Separations

18 pages, 4480 KiB

Open AccessArticle

Polyaniline/Glauconite Nanocomposite Adsorbent for Congo Red Dye from Textile Wastewater

by Doaa Salah, Ahmed Hamd, N. K. Soliman, Ali M. Elzanaty, Abdulaziz M. Alanazi, Mohamed Shaban, Refat El-Sayed and Sayed A. Ahmed

Separations 2022, 9(11), 384; https://doi.org/10.3390/separations9110384 - 21 Nov 2022

Cited by 9 | Viewed by 2932

Abstract

Glauconite (Gl), a naturally occurring clay material, was utilized as an affordable and ecologically friendly adsorbent to explore its capturing capacity towards Congo red (CR) dye from textile industrial waste effluent. To improve adsorption and removal effectiveness, a modification technique utilizing polyaniline (PAN) [...] Read more.

Glauconite (Gl), a naturally occurring clay material, was utilized as an affordable and ecologically friendly adsorbent to explore its capturing capacity towards Congo red (CR) dye from textile industrial waste effluent. To improve adsorption and removal effectiveness, a modification technique utilizing polyaniline (PAN) was investigated. An X-ray diffractometer (XRD), a scanning electron microscope (SEM), and Fourier transformer infrared (FTI-R) were applied as strong familiar characterization techniques for all used adsorbents. The effects of starting concentration, contact duration, adsorbent dose, pH, and temperature on the adsorption process were also studied. The reusability of the adsorbent was studied over four adsorption cycles. The results show that PAN modification of Gl enhances the effectiveness of CR elimination. The clearance efficiency of raw and modified glauconite at 25 °C and pH 7 was 77% and 91%, respectively. The kinetics and isotherms of Congo red dye adsorption were investigated using batch studies to determine the impacts of various experimental conditions. The maximum adsorption capacity of the glauconite/polyaniline (Gl/PAN) nanocomposite rose from 11.9 mg/g for Gl to 14.1 mg/g in accordance with the isotherm analysis, which shows that the Langmuir isotherm properly characterizes the experimental data. The pseudo-second-order model (R² = 0.998) properly expresses the experimental data. The reusability research proved that the adsorbents may be reused effectively. The overall results suggest that the modified Gl by PAN might be used as a low-cost, natural adsorbent for eliminating CR color from textile effluent. Full article

(This article belongs to the Special Issue Applications of Porous Materials in Adsorption)

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18 pages, 1646 KiB

Open AccessArticle

Tribulus terrestris Cytotoxicity against Breast Cancer MCF-7 and Lung Cancer A549 Cell Lines Is Mediated via Activation of Apoptosis, Caspase-3, DNA Degradation, and Suppressing Bcl-2 Activity

by Ali Mohamed Alshabi, Saad Ahmed Alkahtani, Ibrahim Ahmed Shaikh, Mohamed A. A. Orabi, Basel A. Abdel-Wahab, Ismail A. Walbi, Mohammed Shafiuddin Habeeb, Masood Medleri Khateeb, Arun K. Shettar and Joy H. Hoskeri

Separations 2022, 9(11), 383; https://doi.org/10.3390/separations9110383 - 21 Nov 2022

Cited by 1 | Viewed by 2781

Abstract

The primary objective of this research was to use flow cytometry to gain mechanistic insights into the cytotoxic effects of Tribulus terrestris extracts on breast cancer (MCF7) and lung cancer (A549) cell lines. T. terrestris was extracted using a Soxhlet apparatus in a [...] Read more.

The primary objective of this research was to use flow cytometry to gain mechanistic insights into the cytotoxic effects of Tribulus terrestris extracts on breast cancer (MCF7) and lung cancer (A549) cell lines. T. terrestris was extracted using a Soxhlet apparatus in a progressive process. GC–MS was used to establish the phytochemical constituents. The amounts of phenolic compounds and flavonoids in the plant extracts were calculated using spectrophotometric analysis. The cytotoxicity of plant extracts was initially evaluated in non-malignant L929 cells, then in carcinogenic MCF-7 and A549 cell lines. Then, we performed an Annexin V assay, an anti-Bcl-2 assay, a Caspase-3 assay, and a DNA fragmentation (TUNEL) assay, using flow cytometry to investigate the underlying molecular processes. Based on the data, the methanolic extract of T. terrestris contained the highest amounts of phenolic compounds and flavonoids, with values of 169.87 µg GAE/g dwt and 160.12 µg QE/g dwt, respectively. Analysis by GC–MS revealed the presence of bioactive phytochemicals with proven cytotoxicity. Based on the MTT experiment, we determined that the IC₅₀ values for the methanol extract’s effect on the viability of the MCF-7 and A549 cell lines were 218.19 and 179.62 µg/mL, respectively. The aqueous and methanol extracts were less cytotoxic when tested against the cancer-free L929 cell line (IC₅₀ = 224.35 µg/mL). In both breast and lung cancer cells, the methanolic extract was found to activate caspase-3 and inhibit the Bcl-2 protein, resulting in early and late apoptosis and cell death via DNA damage. These findings point to cytotoxic effects of T. terrestris methanol extract against breast and lung cancer cell lines. Due to its potential as a source of anti-cancer chemotherapeutic medicines, T. terrestris warrants further investigation. Full article

(This article belongs to the Special Issue Isolation, Elucidation and Synthesis of Bioactive Natural Products)

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28 pages, 4810 KiB

Open AccessArticle

A New Partially Phosphorylated Polyvinyl Phosphate-PPVP Composite: Synthesis and Its Potentiality for Zr (IV) Extraction from an Acidic Medium

by Antoaneta Ene, Hesham M. H. Zakaly, Amany R. Salem, Ayman A. Gouda, Khalid Althumayri, Khaled F. Alshammari, Hamdi A. Awad, Shams A. M. Issa, Ahmad A. Alluhaybi, Salah A. Zaki, Hala A. Ibrahim, Mohamed A. Gado, Enass M. El-Sheikh and Bahig M. Atia

Separations 2022, 9(11), 382; https://doi.org/10.3390/separations9110382 - 21 Nov 2022

Cited by 5 | Viewed by 2450

Abstract

A newly synthesized partially phosphorylated polyvinyl phosphate derivative (PPVP) was functionalized to extract Zirconium (IV) from Egyptian zircon sand. The specifications for the PPVP composite were approved effectively via different techniques, namely, FT-IR, XPS, BET, EDX, TGA, ¹H-NMR, ¹³C-NMR, GC-MS, XRD [...] Read more.

A newly synthesized partially phosphorylated polyvinyl phosphate derivative (PPVP) was functionalized to extract Zirconium (IV) from Egyptian zircon sand. The specifications for the PPVP composite were approved effectively via different techniques, namely, FT-IR, XPS, BET, EDX, TGA, ¹H-NMR, ¹³C-NMR, GC-MS, XRD and ICP-OES analyses, which demonstrated a satisfactory synthesis of PPVP and zircon dissolution from Egyptian zircon sand. Factors controlling parameters, such as pH values, shaking time, initial zirconium concentration, PPVP dose, nitrate ions concentration, co-ions, temperature and eluting agents, have been optimized. At 25 °C, pH 0, 20 min shaking, 0.05 mol/L zirconium ions and 0.5 mol/L nitrate ions, PPVP has an exciting preservation potential of 195 mg/g, equivalent to 390 mg/L zirconium ions. From the extraction–distribution isotherm, the practical outcomes of Langmuir’s modeling are better than the Freundlich model. With a theoretical value of 196.07 mg/g, which is more in line with the experimental results of 195 mg/g. The zirconium ions adsorption onto the PPVP composite follows the pseudo-second-order kinetics with a theoretical capacity value of 204.08 mg/g. According to thermodynamic potential, the extraction process was expected to be an exothermic, spontaneous and beneficial extraction at low temperatures. The thermodynamic parameters ΔS (−0.03 kJ/mol), ΔH (−12.22 kJ/mol) and ΔG were also considered. As the temperature grows, ∆G values increase from −2.948 kJ/mol at 298 K to −1.941 kJ/mol at 338 K. Zirconium ions may be eluted from the working loaded PPVP by 0.025M HNO₃, with a 99% efficiency rate. It was found that zirconium ions revealed good separation factors towards some co-ions such as Hf⁴⁺ (28.82), Fe³⁺ (10.64), Ti⁴⁺ (28.82), V⁵⁺ (86.46) and U⁶⁺ (68.17). A successful alkali fusion technique with NaOH flux followed by the extraction with PPVP is used to obtain a high-purity zirconia concentrate with a zircon content of 72.77 % and a purity of 98.29%. As a result of this, the improved factors could finally be used. Full article

(This article belongs to the Special Issue Photocatalysis and Adsorption Techniques in Water and Wastewater Treatment)

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15 pages, 2417 KiB

Open AccessArticle

Preparation and Adsorption Properties of Magnetic Molecularly Imprinted Polymers for Selective Recognition of 17β-Estradiol

by Lanbo Bi, Jimin Shen, Zhuoran Yao, Jing Kang, Shengxin Zhao, Pengwei Yan, Binyuan Wang and Zhonglin Chen

Separations 2022, 9(11), 381; https://doi.org/10.3390/separations9110381 - 21 Nov 2022

Cited by 1 | Viewed by 1804

Abstract

In this paper, magnetic molecularly imprinted polymers (MMIPs) were fabricated on the surface of Fe₃O₄ by surface molecular imprinting technology, which can selectively adsorb 17β-estradiol (E2). The optimized experiments demonstrated that MMIPs possessed the best adsorption capacity when methanol was [...] Read more.

In this paper, magnetic molecularly imprinted polymers (MMIPs) were fabricated on the surface of Fe₃O₄ by surface molecular imprinting technology, which can selectively adsorb 17β-estradiol (E2). The optimized experiments demonstrated that MMIPs possessed the best adsorption capacity when methanol was used as the solvent and MAA was used as the crosslinking agent, with a molar ratio of E2: MMA: EGDMA as 1:4:50. SEM, FTIR, and XRD were employed to investigate the morphologies of MMIPs and the results demonstrated that the MMIPs that can selectively adsorb E2 were successfully prepared on Fe₃O₄ particles. The adsorption experiments showed that 92.1% of E2 was adsorbed by the MMIPs, which is higher than the magnetic non-molecularly imprinted polymers (MNIPs). The Freundlich isotherm model was more suitable to describe the adsorption process of E2 by MMIPs. Meanwhile, MMIPs had a better recognition ability for E2 and its structural analogs such as estrone and estriol. The MMIPs still had good adsorption performance after methanol regeneration five times. The prepared MMIPs had the advantages of efficient adsorption ability and high reusability, so they can be applied for selective recognition and removal of E2. Full article

(This article belongs to the Special Issue Development of Materials for Separation and Detection of Metals and Chemicals)

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23 pages, 1592 KiB

Open AccessReview

Extraction, Separation, Antitumor Effect, and Mechanism of Alkaloids in Sophora alopecuroides: A Review

by Ruixia Zhang, Ruizhou Wang, Shipeng Zhao, Dan Chen, Fusheng Hao, Bo Wang, Jin Zhang, Yingying Ma, Xingyi Chen, Xiaojuan Gao, Lu Han and Changcai Bai

Separations 2022, 9(11), 380; https://doi.org/10.3390/separations9110380 - 20 Nov 2022

Cited by 4 | Viewed by 2239

Abstract

Malignant tumors pose a serious threat to human health, reducing quality of life. Natural antitumor drugs play a vital role in the treatment of cancer. Sophora alopecuroides, a traditional Chinese medicine not a part of the Chinese Pharmacopoeia, grows in the arid [...] Read more.

Malignant tumors pose a serious threat to human health, reducing quality of life. Natural antitumor drugs play a vital role in the treatment of cancer. Sophora alopecuroides, a traditional Chinese medicine not a part of the Chinese Pharmacopoeia, grows in the arid desert and edge zone of grassland. Previous studies have extensively investigated the antitumor effects of S. alopecuroides and its major alkaloids. Of these, aloperine, matrine, oxymatrine, sophoridine, and sophocarpine have received the most attention. In recent years, a variety of extraction and separation methods have been applied to the study of the alkaloids of Sophora alopecuroides, which has greatly promoted the study of the chemical constituents and pharmacological activities of the plant. S. alopecuroides has been shown to impede cancer cell growth, induce cell cycle arrest, enhance apoptosis and cellular differentiation, and impede cancer metastasis and invasion. Several mechanisms have been proposed for modulating cancer signaling and molecular pathways or targets based on multitudinous studies in various types of cancerous cells. This review provides an in-depth overview of the antitumor effects of S. alopecuroides and the potential targets of 12 alkaloids in S. alopecuroides via a pharmacophore mapping approach and offers a scientific basis for the further exploration of the mechanism related to the antitumor effects of this plant. Full article

(This article belongs to the Collection Recent Trends in the Separation of Natural Products and Pharmaceuticals)

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28 pages, 4645 KiB

Open AccessArticle

Antioxidant, Anti-Cancer Activity and Phytochemicals Profiling of Kigelia pinnata Fruits

by Khaled M. A. Ramadan, Hossam S. El-Beltagi, Heba I. Mohamed, Tarek A. Shalaby, Ahmed Galal, Abdallah Tageldein Mansour, Mohamed M. Aboul Fotouh and Eslam S. A. Bendary

Separations 2022, 9(11), 379; https://doi.org/10.3390/separations9110379 - 18 Nov 2022

Cited by 16 | Viewed by 4083

Abstract

Over the past few years, research studies on the therapeutic benefits of medicinal plants with potent antioxidant activity and few side effects have grown significantly. This has sparked interest in determining whether naturally occurring antioxidants could take the place of synthetic antioxidants, which [...] Read more.

Over the past few years, research studies on the therapeutic benefits of medicinal plants with potent antioxidant activity and few side effects have grown significantly. This has sparked interest in determining whether naturally occurring antioxidants could take the place of synthetic antioxidants, which are currently being constricted because of their toxic and carcinogenic properties. The identification and quantification of phytochemicals in the methanolic extract of Kigelia pinnata fruits was measured using gas chromatography–mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography–mass spectrometry (UPLC-MS/MS) techniques. Additionally, the methanolic extract of fruits was used to determine antioxidant activity. Free radical-scavenging (DPPH) and ferric ion-reducing antioxidant power were measured using spectrophotometry, and total antioxidant capacity (TAC) was compared with two common antioxidants, vitamin C and α-tocopherol. Moreover, mature fruits have high DDPH, ferric ion-reducing antioxidant power and total antioxidant capacity. Furthermore, mature fruits have high levels of total phenolic, flavonoid, and tannin content; these compounds are thought to be the sources of the antioxidant activity. The major constituents of the methanolic extracts from the mature fruits of K. pinnata were found to be larixinic acid, 3,5-Dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one (DMDP), and 5-Hydrxoymethylfurfural. We performed the elemental analysis of the whole fruit. Huh-7 (liver cancer), PANC-1 (pancreatic cancer), Colo-205 (colorectal cancer), HT-29 (colorectal cancer), SNU-16 (gastric carcinoma), SW620 (colorectal adenocarcinoma) and HCT116 (colon carcinoma) were tested in vitro for anticancer activity. Both methanolic and ethyl acetate extracts of mature fruits had a positive effect on all cancer cell lines as compared to the doxorubicin drug. In addition, the methanolic extracts of mature fruits showed more potent cytotoxic effects than the ethyl acetate extracts. Moreover, the most pronounced cytotoxic effects of the methanolic extract were detected in SW620 (colorectal adenocarcinoma), with an IC₅₀ value of 6.79 μg/mL, SNU-16 (gastric carcinoma), with and IC₅₀ value of 8.69 μg/ ml, and in PANC-1 (pancreatic cancer) with an IC₅₀ value of 10.34 μg/mL. Moreover, the results show that the water, ethyl acetate and methanolic extracts of mature fruits have antioxidant capacity, ferric ion-reducing antioxidant power, DPPH scavenging activity and also anticancer activity. Therefore, the present study suggests that the phytochemical profiles of mature fruits of K. pinnata may be used as potential natural antioxidants and anti-cancer cell lines. Full article

(This article belongs to the Special Issue Exclusive Papers Collection of Scholars Invited by Editorial Board Members of Separations)

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11 pages, 2565 KiB

Open AccessArticle

In-Line Vis-NIR Spectral Analysis for the Column Chromatographic Processes of the Ginkgo biloba L. Leaves. Part II: Batch-to-Batch Consistency Evaluation of the Elution Process

by Wenlong Li, Xi Wang, Houliu Chen, Xu Yan and Haibin Qu

Separations 2022, 9(11), 378; https://doi.org/10.3390/separations9110378 - 18 Nov 2022

Cited by 1 | Viewed by 1738

Abstract

An in-line monitoring method for the elution process of Ginkgo biloba L. leaves using visible and near-infrared spectroscopy in conjunction with multivariate statistical process control (MSPC) was established. Experiments, including normal operating batches and abnormal ones, were designed and carried out. The MSPC [...] Read more.

An in-line monitoring method for the elution process of Ginkgo biloba L. leaves using visible and near-infrared spectroscopy in conjunction with multivariate statistical process control (MSPC) was established. Experiments, including normal operating batches and abnormal ones, were designed and carried out. The MSPC model for the elution process was developed and validated. The abnormalities were detected successfully by the control charts of principal component scores, Hotelling T², or DModX (distance to the model). The results suggested that the established method can be used for the in-line monitoring and batch-to-batch consistency evaluation of the elution process. Full article

(This article belongs to the Special Issue Separation, Extraction and Purification of Natural Products from Plants)

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11 pages, 993 KiB

Open AccessArticle

Establishing and Verifying a Robust Liquid Chromatography-Tandem Mass Spectrometry Method to Simultaneously Measure Seven Androgens Present in Plasma Samples

by Songlin Yu, Yutong Zou, Yicong Yin, Jialei Yu, Qianqian Li, Shaowei Xie, Wei Luo, Xiaoli Ma, Danchen Wang and Ling Qiu

Separations 2022, 9(11), 377; https://doi.org/10.3390/separations9110377 - 17 Nov 2022

Cited by 3 | Viewed by 1937

Abstract

Objectives: To develop a robust liquid chromatography-tandem mass spectrometry (LC–MS/MS) method to simultaneously measure seven human plasma androgens, namely testosterone (T), dihydrotestosterone (DHT), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 11-ketotestosterone (11-KetoT), and 11β-hydroxytestosterone (11β-OHT). Design and Methods: Plasma was extracted via a [...] Read more.

Objectives: To develop a robust liquid chromatography-tandem mass spectrometry (LC–MS/MS) method to simultaneously measure seven human plasma androgens, namely testosterone (T), dihydrotestosterone (DHT), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 11-ketotestosterone (11-KetoT), and 11β-hydroxytestosterone (11β-OHT). Design and Methods: Plasma was extracted via a solid phase extraction method, and the analytical performance of the assay was validated according to the Clinical & Laboratory Standards Institute guidelines. Overall, 73 apparently healthy volunteers were recruited to evaluate the distribution of these seven androgens; their levels in 25 females with acne and 33 obese females were also evaluated. Results: The developed method exhibited a good precision, with the total coefficient variations (CV) and the intra-assay CVs being within 10%. Furthermore, the recoveries of T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT were 90.3–105.8, 88.7–98.1, 92.4–102.5, 90.5–106.7, 87.6–99.9, 93.3–105.3, and 90.2–104.4%, respectively, and no significant matrix effect was observed after internal standard correction (<20%). Moreover, the limits of quantification were 0.01, 0.01, 0.01, 0.10, 5.00, 0.02, and 0.02 ng/mL for T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT, respectively, which are adequate for their accurate measurement in human plasma samples. It was also determined that patients diagnosed with acne had significantly higher levels of DHT, A4, and DHEAS, while those suffering from obesity had significantly higher levels of T and A4 but lower levels of DHT. Conclusions: A robust LC-MS/MS method for the simultaneous determination of seven androgens in plasma samples was successfully established and validated, which plays important roles in clinical application. Full article

(This article belongs to the Special Issue Chromatographic Analysis of Biological Samples)

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14 pages, 2407 KiB

Open AccessArticle

Development of an HPLC-DAD Method for the Extraction and Quantification of 5-Fluorouracil, Uracil, and 5-Fluorodeoxyuridin Monophosphate in Cells and Culture Media of Lactococcus lactis

by Petros Mavromatis, Kyriaki Stampouli, Angeliki Vliora, Anna Mayilyan, Victoria Samanidou and Maria Touraki

Separations 2022, 9(11), 376; https://doi.org/10.3390/separations9110376 - 17 Nov 2022

Cited by 4 | Viewed by 3824

Abstract

The drug 5-fluorouracil (5-FU) is a common cancer chemotherapeutic, presenting toxicity. Mild toxicity is treated with administration of probiotics. The interaction of these probiotics with the drug may have a crucial effect on its therapeutic efficacy. In the present work, a method for [...] Read more.

The drug 5-fluorouracil (5-FU) is a common cancer chemotherapeutic, presenting toxicity. Mild toxicity is treated with administration of probiotics. The interaction of these probiotics with the drug may have a crucial effect on its therapeutic efficacy. In the present work, a method for the quantification of uracil, 5-FU, and its active metabolite 5-fluorodeoxyuridin monophosphate in cells and culture medium of the probiotic L. lactis is presented. Extraction using H₂O containing 0.05% v/v formic acid (1:5 v/v) was followed by ammonium sulphate protein precipitation and SPE. Analysis was conducted in a Nucleosil column using a gradient of water, formic acid, and acetonitrile. Calibration curves were constructed for 5-FU (5–100 μg/mL), uracil (5–20 μg/mL), and 5-fluorodeoxyuridin monophosphate (5–20 μg/mL) using 5-bromouracil as the internal standard (R² ≥ 0.999). The photodegradation of 5-FU amounted to 36.2% at 96 h. An administration experiment in the dark revealed a decline in 5-FU concentration in the culture media (88.3%) and uptake by the cells, while the uracil and FdUMP levels increased in the cells. The inactive metabolite 5,6 dihydrofluorouracil was detected in the medium. Our results demonstrate that uptake and metabolism of 5-FU in L. lactis cells leads to a decline in the drug levels and in the formation of both the active and the inactive metabolites of the drug. Full article

(This article belongs to the Special Issue Women in Separations)

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3 pages, 201 KiB

Open AccessEditorial

Removal of Dye from Aquatic Environments: State-of-the-Art and Future Perspectives

by Amin Mojiri

Separations 2022, 9(11), 375; https://doi.org/10.3390/separations9110375 - 17 Nov 2022

Cited by 3 | Viewed by 1482

Abstract

Surface water sources play a vital role in numerous aspects of societal demand, including as sources of drinking water and water used for agricultural and industrial purposes [...] Full article

10 pages, 3732 KiB

Open AccessArticle

Bioaccumulation of Heavy Metals by Suaeda salsa in the Tidal Flat of the Liaohe Estuary

by Quan Liu, Tongxin Yi, Qiuyu Li, Huiyun Ju and Haifeng Wei

Separations 2022, 9(11), 374; https://doi.org/10.3390/separations9110374 - 16 Nov 2022

Cited by 1 | Viewed by 1421

Abstract

In order to explore the bioaccumulation of heavy metals by Suaeda salsa and its ecological restoration capacity in the tidal flat of the Liaohe estuary, the absorption and reduction effect of Suaeda salsa on heavy metals was determined via a combination of on-site [...] Read more.

In order to explore the bioaccumulation of heavy metals by Suaeda salsa and its ecological restoration capacity in the tidal flat of the Liaohe estuary, the absorption and reduction effect of Suaeda salsa on heavy metals was determined via a combination of on-site monitoring and experimental tests. The results showed that, under a high-salt environment, Suaeda salsa had a decreasing effect on heavy metals zinc, copper and lead, and the bioaccumulation coefficient BCF_S_s–Zn > BCF_S_s–Cu > BCF_S_s–Pb. When the concentration of heavy metal ions was high, Suaeda salsa could still survive, but the absorptivity was low, reducing its ability to repair heavy metal pollution. By correlating the research data with the population density of Suaeda salsa, the total removal of heavy metals was obtained, about 2008.6 kg Zn²⁺, 347.5 kg Cu²⁺, 376.1 kg Pb²⁺. This paper could provide a theoretical basis and technical support for the promotion and application of ecological restoration via Suaeda salsa. Full article

(This article belongs to the Section Environmental Separations)

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16 pages, 3037 KiB

Open AccessArticle

Solid-Phase Extraction and Characterization of Quercetrin-Rich Fraction from Melastoma malabathricum Leaves

by Mohd Azrie Awang, Lee Suan Chua and Luqman Chuah Abdullah

Separations 2022, 9(11), 373; https://doi.org/10.3390/separations9110373 - 15 Nov 2022

Cited by 2 | Viewed by 2267

Abstract

This study was focused on the recovery of quercetrin from the crude extract of Melastoma malabathricum leaves using the technique of solid-phase extraction. The process variables and their ranges were screened using one-factor-at-a-time and statistically optimized using the response surface methodology. The results [...] Read more.

This study was focused on the recovery of quercetrin from the crude extract of Melastoma malabathricum leaves using the technique of solid-phase extraction. The process variables and their ranges were screened using one-factor-at-a-time and statistically optimized using the response surface methodology. The results found that 9.13 mg/mL of crude extract required 18.24 mL of 70.5% methanol as the eluent to yield an 86.6% w/w fraction containing 36.02 mg/g of quercetrin. The process increased quercetrin from 1% w/w in the crude extract to 4% w/w in the fraction. Quercetrin was likely to be the compound contributing to antiradical and antidiabetic activities. In silico simulation showed that quercetrin had low binding energy and mostly bound with charged (Glu and Arg) and aromatic (Tyr and Phe) amino acids via hydrogen bonds. Its inhibitory progress against DPP-IV was faster than crude extract at low concentration (<100 µg/mL). Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

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13 pages, 3003 KiB

Open AccessArticle

Mitigation Mechanism of Membrane Fouling in MnFeOx Functionalized Ceramic Membrane Catalyzed Ozonation Process for Treating Natural Surface Water

by Hui Guo, Yanxiao Chi, Yifan Jia, Manman Li, Yuxuan Yang, Haiyong Yao, Kunlun Yang, Zengshuai Zhang, Xueli Ren, Peng Gu and Hengfeng Miao

Separations 2022, 9(11), 372; https://doi.org/10.3390/separations9110372 - 15 Nov 2022

Cited by 2 | Viewed by 1533

Abstract

In order to efficiently remove NOMs in natural surface water and alleviate membrane pollution at the same time, a flat microfiltration ceramic membrane (CM) was modified with MnFeO_X (Mn-Fe-CM), and a coagulation–precipitation–sand filtration pretreatment coupled with an in situ ozonation-ceramic membrane filtration [...] Read more.

In order to efficiently remove NOMs in natural surface water and alleviate membrane pollution at the same time, a flat microfiltration ceramic membrane (CM) was modified with MnFeO_X (Mn-Fe-CM), and a coagulation–precipitation–sand filtration pretreatment coupled with an in situ ozonation-ceramic membrane filtration system (Pretreatment/O₃/Mn-Fe-CM) was constructed for this study. The results show that the removal rates of dissolved organic carbon (DOC), specific ultraviolet absorption (SUVA) and NH₄⁺-N by the Pretreatment/O₃/Mn-Fe-CM system were 51.1%, 67.9% and 65.71%, respectively. Macromolecular organic compounds such as aromatic proteins and soluble microbial products (SMPs) were also effectively removed. The working time of the membrane was about twice that in the Pretreatment/CM system without the in situ ozone oxidation, which was measured by the change in transmembrane pressure, proving that membrane fouling was significantly reduced. Finally, based on the SEM, AFM and other characterization results, it was concluded that the main mitigation mechanisms of membrane fouling in the Pretreatment/O₃/Mn-Fe-CM system was as follows: (1) pretreatment could remove part of DOC and SUVA to reduce their subsequent entrapment on a membrane surface; (2) a certain amount of shear force generated by O₃ aeration can reduce the adhesion of pollutants; (3) the loaded MnFeO_X with a higher catalytic ability produced a smoother active layer on the surface of the ceramic membrane, which was conducive in reducing the contact among Mn-Fe-CM, O₃ and pollutants, thus increasing the proportion of reversible pollution and further reducing the adhesion of pollutants; (4) Mn-Fe-CM catalyzed O₃ to produce ·OH to degrade the pollutants adsorbed on the membrane surface into smaller molecular organic matter, which enabled them pass through the membrane pores, reducing their accumulation on the membrane surface. Full article

(This article belongs to the Special Issue Recent Advances in Membrane Technologies for Water/Wastewater Treatment)

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51 pages, 4273 KiB

Open AccessReview

Assessment of the Equilibrium Constants of Mixed Complexes of Rare Earth Elements with Acidic (Chelating) and Organophosphorus Ligands

by Maria Atanassova

Separations 2022, 9(11), 371; https://doi.org/10.3390/separations9110371 - 14 Nov 2022

Cited by 2 | Viewed by 1931

Abstract

A survey of the experimental equilibrium constants in solution for the mixed complexes of 4f ions with acidic (chelating) and O-donor organophosphorus ligands published in the period between 1954 and 2022 is presented. These data are widely used in both analytical and solvent [...] Read more.

A survey of the experimental equilibrium constants in solution for the mixed complexes of 4f ions with acidic (chelating) and O-donor organophosphorus ligands published in the period between 1954 and 2022 is presented. These data are widely used in both analytical and solvent extraction chemistry. Important data evaluation criteria involved the specification of the essential reactions, process conditions and the correctness of techniques and calculations used, as well as appropriate equilibrium analysis of experimental data. Higher-quality data have been evaluated, compiled and presented herein, providing a synoptic view of the unifying theme in this area of research, i.e., synergism. Full article

(This article belongs to the Section Chromatographic Separations)

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28 pages, 1968 KiB

Open AccessEditor’s ChoiceReview

Metal-Chelating Peptides Separation Using Immobilized Metal Ion Affinity Chromatography: Experimental Methodology and Simulation

by Rachel Irankunda, Jairo Andrés Camaño Echavarría, Cédric Paris, Loïc Stefan, Stéphane Desobry, Katalin Selmeczi, Laurence Muhr and Laetitia Canabady-Rochelle

Separations 2022, 9(11), 370; https://doi.org/10.3390/separations9110370 - 14 Nov 2022

Cited by 16 | Viewed by 7006

Abstract

Metal-Chelating Peptides (MCPs), obtained from protein hydrolysates, present various applications in the field of nutrition, pharmacy, cosmetic etc. The separation of MCPs from hydrolysates mixture is challenging, yet, techniques based on peptide-metal ion interactions such as Immobilized Metal Ion Affinity Chromatography (IMAC) seem [...] Read more.

Metal-Chelating Peptides (MCPs), obtained from protein hydrolysates, present various applications in the field of nutrition, pharmacy, cosmetic etc. The separation of MCPs from hydrolysates mixture is challenging, yet, techniques based on peptide-metal ion interactions such as Immobilized Metal Ion Affinity Chromatography (IMAC) seem to be efficient. However, separation processes are time consuming and expensive, therefore separation prediction using chromatography modelling and simulation should be necessary. Meanwhile, the obtention of sorption isotherm for chromatography modelling is a crucial step. Thus, Surface Plasmon Resonance (SPR), a biosensor method efficient to screen MCPs in hydrolysates and with similarities to IMAC might be a good option to acquire sorption isotherm. This review highlights IMAC experimental methodology to separate MCPs and how, IMAC chromatography can be modelled using transport dispersive model and input data obtained from SPR for peptides separation simulation. Full article

(This article belongs to the Section Bioanalysis/Clinical Analysis)

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19 pages, 2209 KiB

Open AccessArticle

Deep Eutectic Solvents for the Separation of Toluene/1-Hexene via Liquid–Liquid Extraction

by Mohamed K. Hadj-Kali, Lahssen El Blidi, Sarwono Mulyono, Irfan Wazeer, Emad Ali and Jagan Rallapalli

Separations 2022, 9(11), 369; https://doi.org/10.3390/separations9110369 - 14 Nov 2022

Cited by 5 | Viewed by 2420

Abstract

The separation of aromatic/olefin mixtures is a difficult task in the petrochemical industry, since the boiling points of these hydrocarbons are very similar. This work aims to use deep eutectic solvents (DESs) for the extraction of toluene from 1-hexene by liquid–liquid extraction. A [...] Read more.

The separation of aromatic/olefin mixtures is a difficult task in the petrochemical industry, since the boiling points of these hydrocarbons are very similar. This work aims to use deep eutectic solvents (DESs) for the extraction of toluene from 1-hexene by liquid–liquid extraction. A total of 53 DESs were studied qualitatively and quantitatively using the COSMO-RS approach to separate the binary mixture of toluene and 1-hexene. The selectivity, capacity, and performance index of all DESs were evaluated by calculating the activity coefficient at infinite dilution. The σ-profile and σ-potential of each component were interpreted to evaluate the interactions between the different species. We then selected three DESs for experimental validation, namely benzyltriphenylphosphonium chloride:triethylene glycol BzTPPCl:TEG (1:8), tetrabutylammonium bromide:triethylene glycol TBABr:TEG (1:3), and tetrabutylammonium bromide:ethylene glycol TBABr: EG (1:4). Experimental liquid–liquid equilibrium data were obtained for the ternary mixtures {1-hexene (1) + toluene (2) + DES (3)} at T = 298.15 K and atmospheric pressure. Based on the selectivity data and the solute distribution ratio, the feasibility of different DESs as extractive solvents was tested. Finally, ¹H NMR was performed to elucidate the extraction mechanism. No DES was found in the raffinate phase, indicating minimal cross-contamination. Full article

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13 pages, 2032 KiB

Open AccessArticle

Development of Novel Formaldehyde-Free Melamine Resin for Retanning of Leather and Reduced Effluent Discharge in Water

by Muhammad Naveed Ashraf, Azhar Ali, Muhammad Bilal Shakoor, Sajid Rashid Ahmad, Fida Hussain and Sang-Eun Oh

Separations 2022, 9(11), 368; https://doi.org/10.3390/separations9110368 - 13 Nov 2022

Cited by 4 | Viewed by 2814

Abstract

The objective of this study was to develop a novel melamine-based resin suitable for producing formaldehyde-free leather with improved retanning properties. The resin was prepared by optimized condensation of melamine, glyoxal and metanilic acid. The novel resin was compared with a commercial resin [...] Read more.

The objective of this study was to develop a novel melamine-based resin suitable for producing formaldehyde-free leather with improved retanning properties. The resin was prepared by optimized condensation of melamine, glyoxal and metanilic acid. The novel resin was compared with a commercial resin against different parameters. Functional group analysis of the polymer structure and the route of synthesis was verified with the help of FT-IR spectroscopy. A Leica metallurgical microscope coupled with a CCD camera was used for SEM analysis. The results revealed that the mechanical and organoleptic properties of the novel resin were better than those of the commercial melamine resin. Tensile strength, tear strength and percentage elongation of leather were increased by 17.43%, 10.41% and 8.62%, respectively, in the direction parallel to the backbone, while the increases in these parameters were 15.17%, 9.79% and 6.0%, respectively, in the direction perpendicular to the backbone at the same dose. We observed a 100% reduction in free formaldehyde content in retanned leather as well as in effluent produced by the novel melamine resin. Pollution load study of effluent showed reductions in chemical oxygen demand, total suspended solids and total dissolved solids by 9.21%, 5.60% and 6.97%, respectively, for the novel melamine resin, reflecting its improved exhaustion. The fiber structure of the leather produced by the novel melamine resin was more orderly arranged, showing its improved retanning. These results prove that the novel melamine resin is an effective retanning agent suitable for producing formaldehyde-free leather with a reduction in effluent pollution load. This work introduces an alternative to formaldehyde for amino resins to address its carcinogenic effects. Full article

(This article belongs to the Special Issue Applications of Porous Materials in Adsorption)

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17 pages, 1065 KiB

Open AccessArticle

Non-Targeted Chemical Characterization of JUUL-Menthol-Flavored Aerosols Using Liquid and Gas Chromatography

by Mark R. Crosswhite, Lena N. Jeong, Patrick C. Bailey, J. Brian Jameson, Anastasia Lioubomirov, David Cook, Clarissa Yang, Adam Ozvald, Matthew Lyndon and I. Gene Gillman

Separations 2022, 9(11), 367; https://doi.org/10.3390/separations9110367 - 11 Nov 2022

Cited by 9 | Viewed by 2734

Abstract

The aerosol constituents generated from JUUL Menthol pods with 3.0% and 5.0% nicotine by weight (Me3 and Me5) are characterized by a non-targeted approach, which was developed to detect aerosol constituents that are not known to be present beforehand or that may be [...] Read more.

The aerosol constituents generated from JUUL Menthol pods with 3.0% and 5.0% nicotine by weight (Me3 and Me5) are characterized by a non-targeted approach, which was developed to detect aerosol constituents that are not known to be present beforehand or that may be measured with targeted methods. Three replicates from three production batches (n = 9) were aerosolized using two puffing regimens (intense and non-intense). Each of the 18 samples were analyzed by gas chromatography electron ionization mass spectrometry and by liquid chromatography electrospray ionization high-resolving power mass spectrometry. All chemical constituents determined to differ from control were identified and semi-quantified. To have a complete understanding of the aerosol constituents and chemistry, each chemical constituent was categorized into one of five groups: (1) flavorants, (2) harmful and potentially harmful constituents, (3) leachables, (4) reaction products, and (5) chemical constituents that were unable to be identified or rationalized (e.g., chemical constituents that could not be categorized in groups (1–4). Under intense puffing, 74 chemical constituents were identified in Me3 aerosols and 68 under non-intense puffing, with 53 chemical constituents common between both regimens. Eighty-three chemical constituents were identified in Me5 aerosol using an intense puffing regimen and seventy-five with a non-intense puffing regimen, with sixty-two chemical constituents in common. Excluding primary constituents, reaction products accounted for the greatest number of chemical constituents (approximately 60% in all cases, ranging from about 0.05% to 0.1% by mass), and flavorants—excluding menthol—comprised the second largest number of chemical constituents (approximately 25%, ranging consistently around 0.01% by mass). The chemical constituents detected in JUUL aerosols were then compared to known constituents from cigarette smoke to determine the relative chemical complexities and commonalities/differences between the two. This revealed (1) a substantial decrease in the chemical complexity of JUUL aerosols vs. cigarette smoke and (2) that there are between 55 (Me3) and 61 (Me5) unique chemical constituents in JUUL aerosols not reported in cigarette smoke. Understanding the chemical complexity of JUUL aerosols is important because the health effects of combustible cigarette smoke are related to the combined effect of these chemical constituents through multiple mechanisms, not just the effects of any single smoke constituent. Full article

(This article belongs to the Special Issue Exclusive Papers Collection of Scholars Invited by Editorial Board Members of Separations)

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17 pages, 3841 KiB

Open AccessArticle

Unveiling the Use of Wide Horizontal Rim Vessels (Bronze Age Northwest Iberian Peninsula)

by César Oliveira, Raquel Vilaça, André Lopes Pereira and Anna Lígia Vitale

Separations 2022, 9(11), 366; https://doi.org/10.3390/separations9110366 - 10 Nov 2022

Cited by 1 | Viewed by 2188

Abstract

This paper addresses a “wide horizontal rim vessel” belonging to the collection of Fundação Sousa d’Oliveira (Azores). Although its provenance and the circumstances of its discovery are currently unknown, the authors contend that this vessel should be attributed to the Iberian Northwest and, [...] Read more.

This paper addresses a “wide horizontal rim vessel” belonging to the collection of Fundação Sousa d’Oliveira (Azores). Although its provenance and the circumstances of its discovery are currently unknown, the authors contend that this vessel should be attributed to the Iberian Northwest and, more specifically, to the Portuguese territory, in line with the highly homogenous distribution of this type of pottery. A morphological and stylistic study has been carried out establishing its singularity with regards to the decorative composition of the rim, which is without parallel amongst dozens of vessels of the same “family”. During the study of this piece, it has been possible to observe traces of soot and organic residues deposited both on its interior and exterior surfaces, which is recurrent in these vessels. The nature of these substances has never been determined in previous studies. In this article, we present and discuss the results obtained from the chromatographic analyses of the organic residue traces found on the vessel. Full article

(This article belongs to the Special Issue Analytical Chromatography Applied to Archaeology)

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15 pages, 2524 KiB

Open AccessArticle

Interaction of Manganese Ions with Scheelite Surfaces and Its Effect on Collector Adsorption and Flotation

by Xiao Wang, Shuming Wen, Qi Zuo, Runpeng Liao, Shengbing Meng, Yuanyuan Tao, Zhihao Shen and Qicheng Feng

Separations 2022, 9(11), 365; https://doi.org/10.3390/separations9110365 - 10 Nov 2022

Cited by 3 | Viewed by 1593

Abstract

Tungsten is a commercially important metal element that usually coexists with a variety of non-ferrous metals, which makes its extraction difficult. Scheelite is a commonly occurring tungsten-containing ore with the formula CaWO₄. Improving the surface properties of scheelite to increase its [...] Read more.

Tungsten is a commercially important metal element that usually coexists with a variety of non-ferrous metals, which makes its extraction difficult. Scheelite is a commonly occurring tungsten-containing ore with the formula CaWO₄. Improving the surface properties of scheelite to increase its adsorption of the collector for flotation separation is the focus of our current research. In this paper, the effects of manganese ions on scheelite flotation in benzohydroxamic acid (BHA) system were studied by micro-flotation tests, adsorption tests, fourier transform infrared spectroscopy (FTIR), zeta potential, and X-ray photoelectron spectroscopy (XPS) analysis. The addition of Mn²⁺ was found to improve the recovery of scheelite. The addition of Mn²⁺ greatly improved the recovery of scheelite. Infrared spectroscopy, adsorption tests, zeta potential measurements and XPS analysis all confirmed that BHA had a higher adsorption capacity and a stronger bond to the surface of scheelite after the addition of manganese ions, increasing the floatability of scheelite particles. Therefore, Mn²⁺ shows great potential for the improvement of the flotation index of scheelite in a system with BHA. Full article

(This article belongs to the Special Issue Mineral Flotation)

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19 pages, 2891 KiB

Open AccessArticle

Numerical Modeling and Analysis of Harvesting Atmospheric Water Using Porous Materials

by Sadeem S. Alkinani, Mohamed F. El-Amin and Tayeb Brahimi

Separations 2022, 9(11), 364; https://doi.org/10.3390/separations9110364 - 10 Nov 2022

Cited by 3 | Viewed by 3049

Abstract

Nowadays, harvesting water from the atmosphere is becoming a new alternative for generating fresh water. To the author’s best knowledge, no mathematical model has been established to describe the process of harvesting water from the atmosphere using porous materials. This research seeks to [...] Read more.

Nowadays, harvesting water from the atmosphere is becoming a new alternative for generating fresh water. To the author’s best knowledge, no mathematical model has been established to describe the process of harvesting water from the atmosphere using porous materials. This research seeks to develop a new mathematical model for water moisture absorption in porous materials to simulate and assess harvesting atmospheric water. The mathematical model consists of a set of governing partial differential equations, including mass conservation equation, momentum equation, associated parameterizations, and initial/boundary conditions. Moreover, the model represents a two-phase fluid flow that contains phase-change gas–liquid physics. A dataset has been collected from the literature containing five porous materials that have been experimentally used in water generation from the air. The five porous materials include copper chloride, copper sulfate, magnesium sulfate, manganese oxides, and crystallites of lithium bromide. A group of empirical models to relate the relative humidity and water content have been suggested and combined with the governing to close the mathematical system. The mathematical model has been solved numerically for different times, thicknesses, and other critical parameters. A comparison with experimental findings was made to demonstrate the validity of the simulation model. The results show that the proposed mathematical model precisely predicts the water content during the absorption process. In addition, the simulation results show that; during the absorption process, when the depth is smaller, the water content reaches a higher saturation point quickly and at a lower time, i.e., quick process. Finally, the highest average error of the harvesting atmospheric water model is around 1.9% compared to experimental data observed in manganese oxides. Full article

(This article belongs to the Special Issue Photocatalysis and Adsorption Techniques in Water and Wastewater Treatment)

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11 pages, 2062 KiB

Open AccessArticle

GC-MS Analysis, Phytochemical Screening, and Antibacterial Activity of Cerana indica Propolis from Kashmir Region

by Ishfaq Mohiuddin, T. Ramesh Kumar, Mohammed Iqbal Zargar, Shahid Ud Din Wani, Wael A. Mahdi, Sultan Alshehri, Prawez Alam and Faiyaz Shakeel

Separations 2022, 9(11), 363; https://doi.org/10.3390/separations9110363 - 9 Nov 2022

Cited by 8 | Viewed by 3303

Abstract

Propolis is a resinous compound produced by honey bees. It contains bioactive molecules that possess a wide range of biological functions. The chemical composition of propolis is affected by various variables, including the vegetation, the season, and the area from which the sample [...] Read more.

Propolis is a resinous compound produced by honey bees. It contains bioactive molecules that possess a wide range of biological functions. The chemical composition of propolis is affected by various variables, including the vegetation, the season, and the area from which the sample was collected. The aim of this study was to analyze the chemical composition and assess Cerana indica propoli’s antibacterial efficacy from the Kashmir region. Gas chromatography-mass spectrometry (GC-MS) analysis was used to determine the chemical composition of Kashmiri propolis. A range of bacterial strains was tested for antimicrobial activity using different extracts of propolis by agar well diffusion technique. Propolis was found to be rich in alkaloids, saponins, tannins, and resins. The chemical characterization revealed the presence of 68 distinct phytocompounds using GC-MS, and the most predominant compounds were alpha-D-mannopyranoside, methyl, cyclic 2,3:4,6-bis-ethyl boronate (21.17%), followed by hexadecanoic acid, methyl ester (9.91%), and bacteriochlorophyll-c-stearyl (4.41%). The different extracts of propolis showed specific antibacterial efficacy against multidrug-resistant (MDR) strains viz., Pseudomonas aeruginosa (MTCC1688), Escherichiacoli (MTCC443), Klebsiella pneumonia (MTCC19), Cutibacterium acnes (MTCC843), and Staphylococcus aureus (MTCC96). The EEKP showed the highest zone of inhibition against S. aureus (17.33) at 400 µg mL⁻¹. According to the findings of this study, bee propolis contains a variety of secondary metabolites with various pharmacological activities. Furthermore, because of its broad spectrum of positive pharmacological actions and the fact that it is a promising antibacterial agent, more research on propolis is warranted. Full article

(This article belongs to the Special Issue Analysis of Natural Bioactive Compounds in Plant, Food, and Pharmaceutical Products Using Chromatographic Techniques)

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13 pages, 2702 KiB

Open AccessArticle

Evaluating the Applicability of High-Speed Air Flotation Technology for Water Supply: A Case Study in Tianjin Binhai New Area

by Shuyan Gong, Hongpeng Wang, Shuang Zhang, Shaohong Jiang, Xinjuan Zhao and Qidong Hou

Separations 2022, 9(11), 362; https://doi.org/10.3390/separations9110362 - 9 Nov 2022

Cited by 2 | Viewed by 1864

Abstract

The development and application of advanced water purification technology is crucial to guarantee a sufficient supply of clean water. However, conventional water purification technology consumes large amounts of coagulants, with the formation of intractable sludge. Herein, the applicability of high-speed air flotation technology [...] Read more.

The development and application of advanced water purification technology is crucial to guarantee a sufficient supply of clean water. However, conventional water purification technology consumes large amounts of coagulants, with the formation of intractable sludge. Herein, the applicability of high-speed air flotation technology for the purification of actual water sources was evaluated in Tianjin Binhai New Area. During a three-year survey, the raw water exhibited periodic pollution characteristics with algae cells as the main removal targets in all seasons. The raw water had both low temperatures and low turbidity in winter, another obstacle for water treatment. Based on the scientific analysis of the water’s quality, the water purification process was comprehensively optimized via regulating the dosage of agents and operating parameters and using high-speed air flotation equipment. The results showed that a dissolved air pressure of 0.40 MPa, reflux ratio of 8%, and SUEZ-1# dissolved air release head combined with pre-chlorination with PACl plus FeCl₃ (PACl/FeCl₃ ratio = 2:1) were suitable for attaining a good purification performance. High turbidity removal rates (80.9–86.2%) and algae cell removal rates (92.5–98.1%) were obtained even in the high algae period of summer and low turbidity period in the winter, proving the superior stability and applicability of the high-speed air flotation system. Full article

(This article belongs to the Section Environmental Separations)

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21 pages, 2112 KiB

Open AccessArticle

Box–Behnken Design Based Development of UV-Reversed Phase High Performance Liquid Chromatographic Method for Determination of Ascorbic Acid in Tablet Formulations

by Syed Najmul Hejaz Azmi, Umaima Al Hoqani, Juhaina Obaid Said Al Mamari, Buthaina Mohamed Salim Al Mamari, Balaqis Sultan Ali Rashid Al Jassasi, Aziza Saleh Saif Al Rubaiai, Nafisur Rahman, Mohd Nasir, Sk Manirul Haque, Shah Alam Khan, Qamar Uddin Ahmed and Zainul Amiruddin Zakaria

Separations 2022, 9(11), 361; https://doi.org/10.3390/separations9110361 - 9 Nov 2022

Cited by 8 | Viewed by 2848

Abstract

A simple, sensitive, accurate and inexpensive UV-reversed-phase high-performance liquid chromatographic method was developed for the determination of ascorbic acid in tablet formulations. The method was based on the separation of ascorbic acid using a mobile phase of an acetonitrile-NaH₂PO₄-H [...] Read more.

A simple, sensitive, accurate and inexpensive UV-reversed-phase high-performance liquid chromatographic method was developed for the determination of ascorbic acid in tablet formulations. The method was based on the separation of ascorbic acid using a mobile phase of an acetonitrile-NaH₂PO₄-H₃PO₄ buffer solution (pH = 3) (5:95 v/v) with a UV detection wavelength of 245 nm and a flow rate of 0.8 mL min⁻¹ at ambient column temperature. The variables of the proposed method, such as acetonitrile fraction (%), flow rate (mL min⁻¹) and column temperature (°C), were optimized on the peak area by response surface methodology via the Box–Behnken design. The mobile phase was passed isocratically, and the separation of ascorbic acid was performed at the retention time of 4.1 min. A calibration graph was obtained and found to be linear in the concentration range of 10–180 µg mL⁻¹. The method suitability was assessed and an asymmetry factor of 1.15 was obtained. The proposed method was successfully applied for the determination of ascorbic acid in tablet formulations and statistically compared with the results of the reference method. The performance of the proposed method was excellent and in agreement with the reference method. The recovery percentage of the proposed and reference methods was in the range of 99.98–100.04% and showed compliance (100 ± 2%) with regulatory guidelines. Full article

(This article belongs to the Special Issue HPLC: A Key Tool for Analytical Chemistry)

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12 pages, 1792 KiB

Open AccessArticle

Evaluation of Anti-Venom Potential of Areca catechu Seed Extract on Bungarus caeruleus Venom

by Veena More, Abdullatif Bin Muhsinah, G. S. Latha, Abdulfattah Yahya M. Alhazmi, Osama Abdulaziz Ibrahim, Abdulkarim S. Binshaya, Mater H. Mahnashi, Hassan H. Almasoudi, Harshitha Gangadharappa, Sahana Nagappa Maruthi, Sindhoora Rao, Bhavya Janardhan, Aejaz Abdullatif Khan, Uday M. Muddapur, Ibrahim Ahmed Shaikh and Sunil S. More

Separations 2022, 9(11), 360; https://doi.org/10.3390/separations9110360 - 9 Nov 2022

Cited by 3 | Viewed by 2453

Abstract

Areca catechu seeds and their extract/s are currently used to treat various ailments and infections including snakebites. The purpose of this investigation was to assess the inhibiting/neutralizing effect of ethyl acetate and aqueous ethanolic seed extracts of A. catechu on Bungarus caeruleus (krait) [...] Read more.

Areca catechu seeds and their extract/s are currently used to treat various ailments and infections including snakebites. The purpose of this investigation was to assess the inhibiting/neutralizing effect of ethyl acetate and aqueous ethanolic seed extracts of A. catechu on Bungarus caeruleus (krait) venom. The enzyme activities and their inhibition were evaluated using standard procedures (in vitro). In vivo studies were conducted using chick embryos and murine models. The extracts inhibited hyaluronidase and phospholipase A₂ activities. Protease activity was neutralized by the aqueous ethanolic extract only. The IC₅₀ value of aqueous ethanolic extract for hyaluronidase was 0.001 g/mL, while that for the ethyl acetate extract for phospholipase A₂ was 0.006 g/mL. In addition, both the extracts neutralized the indirect hemolysis and fibrinogenolytic activity induced by B. caeruleus venom. The LD₅₀ for the chick embryos was 4.9 µg/egg. The 50 and 100 µg aqueous ethanolic extracts neutralized the LD₅₀ and the challenging dose (3LD₅₀) of venom effectively in the chick embryo model. The LD₅₀ of B. caeruleus venom in mice was 0.1927 µg/kg; the extract extended the survival time of the mice from 25 min to 30 and 35 min in 1:10 and 1:20 ((w/w) venom:extract) ratios, respectively. The extract also neutralized myotoxic activity. The A. catechu seed extract showed promising inhibitory properties against B. caeruleus venom. In this regard, academia and industries should work collaboratively to develop and formulate a cost-effective first-aid drug. Full article

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26 pages, 1156 KiB

Open AccessArticle

Phytochemical and Biological Characterization of the Fractions of the Aqueous and Ethanolic Extracts of Parthenium hysterophorus

by Miguel A. Alfaro Jiménez, Alejandro Zugasti Cruz, Sonia Y. Silva Belmares, Juan A. Ascacio Valdés and Crystel A. Sierra Rivera

Separations 2022, 9(11), 359; https://doi.org/10.3390/separations9110359 - 9 Nov 2022

Cited by 1 | Viewed by 2783

Abstract

In this study, the fractions of the aqueous (AE) and ethanolic (EE) crude extracts of Parthenium hysterophorus were evaluated for their phytochemical composition, cytotoxic, and antioxidant activity. The two extracts were subjected to a fractionation by vacuum liquid chromatography, obtaining seven fractions for [...] Read more.

In this study, the fractions of the aqueous (AE) and ethanolic (EE) crude extracts of Parthenium hysterophorus were evaluated for their phytochemical composition, cytotoxic, and antioxidant activity. The two extracts were subjected to a fractionation by vacuum liquid chromatography, obtaining seven fractions for each extract. These fractions were evaluated for the presence of phenolic compounds by reverse phase high performance liquid chromatography coupled to mass spectrometer (RP-HPLC-MS) analysis. Their cytotoxic activity was tested with a hemolysis assay. The antioxidant activity was evaluated with the Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and hydroxyl radical (–OH) scavenging assays. In addition, the effect of the fractions on the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), from human erythrocytes, was evaluated. The phytochemical screening by RP-HPLC-MS mainly showed the presence of flavonoids and hydroxycinnamic acids. The hemolysis assay exhibited a low cytotoxic activity by the fractions of the AE, but the fractions of the EE exhibited a hemolytic effect. The fractions of the AE and EE showed significant antioxidant activity to inhibit radicals in the three radical scavenging assays. Moreover, only some fractions of the AE showed a significant increase in the activity of the SOD enzyme, while the activity of CAT exhibited a significant increase by the fractions of the two extracts. The fractions of the AE and EE of P. hysterophorus have phytochemicals with antioxidant activity to inhibit radicals and increase the activity of in vitro antioxidant enzymes. Full article

(This article belongs to the Special Issue Separation, Extraction and Purification of Natural Products)

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8 pages, 2879 KiB

Open AccessFeature PaperArticle

Automated Image Analysis for Retention Determination in Centrifugal Partition Chromatography

by Felix Buthmann, Florian Pley, Gerhard Schembecker and Jörg Koop

Separations 2022, 9(11), 358; https://doi.org/10.3390/separations9110358 - 8 Nov 2022

Cited by 4 | Viewed by 1701

Abstract

In Centrifugal Partition Chromatography, two immiscible liquids are used as mobile and stationary phases. During operation, bleeding of the stationary phase cannot be eliminated completely. For optimal separation performance, however, it is crucial to maintain sufficient amounts of stationary phase in the system, [...] Read more.

In Centrifugal Partition Chromatography, two immiscible liquids are used as mobile and stationary phases. During operation, bleeding of the stationary phase cannot be eliminated completely. For optimal separation performance, however, it is crucial to maintain sufficient amounts of stationary phase in the system, which is quantitatively measured by the retention value. With an online measurement of that retention value, it is possible to make predictions about the separation performance of the system. Therefore, an image processing algorithm was developed in this study, allowing quick and effortless online evaluation of retention by image analysis. Finally, the results were compared with proven analysis methods to evaluate the measurements’ validity. With the help of the new algorithm, it was possible to improve the number of pictures analyzed per time and the precision compared to the previously used technique. Full article

(This article belongs to the Collection Feature Paper Collection in Section Chromatographic Separations)

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9 pages, 937 KiB

Open AccessCommunication

A Neglected Issue: Stationary Phase Retention Determination of Classic High-Speed Counter-Current Chromatography Solvent Systems

by Sha Li, Tiandan Li, Xiaochao Hu, Yong Yang, Yangyi Huang and Kai He

Separations 2022, 9(11), 357; https://doi.org/10.3390/separations9110357 - 8 Nov 2022

Cited by 3 | Viewed by 1671

Abstract

Obtaining an ideal solvent system for target compounds is still an obstacle to the wide application of high-speed counter-current chromatography (HSCCC). The partition coefficient and retention of the stationary phase are two key parameters for solvent system selection. The retention of the stationary [...] Read more.

Obtaining an ideal solvent system for target compounds is still an obstacle to the wide application of high-speed counter-current chromatography (HSCCC). The partition coefficient and retention of the stationary phase are two key parameters for solvent system selection. The retention of the stationary phase of the solvent system is roughly judged by settling time using a test tube, which is subjective and inaccurate. In this study, we demonstrated that high-resolution separation of HSCCC is tightly connected with the retention of the stationary phase. Notably, unlike the in vitro test of settling time, we investigated the retention of the stationary phase of classical biphasic solvent systems by a TBE300C HSCCC apparatus. Our results revealed that settling time is not always inversely proportional to the retention of the stationary phase. The n-hexane–ethylacetate–methanol–water solvent systems showed the highest correlation coefficient of settling time and retention of the stationary phase (r = −0.91, n = 16). N-heptane–n-butanol–acetonitrile–water solvent system showed the lowest correlation coefficient (r = −0.26, n = 7). These results may be helpful for HSCCC solvent system selection and accelerate the application of this technique. Full article

(This article belongs to the Special Issue Novel Applications of Separation Technology)

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23 pages, 5474 KiB

Open AccessArticle

Polymer-Based Nano-Adsorbent for the Removal of Lead Ions: Kinetics Studies and Optimization by Response Surface Methodology

by Abdullahi Haruna Birniwa, Sana Kehili, Mujahid Ali, Haruna Musa, Umar Ali, Shamsul Rahman Mohamed Kutty, Ahmad Hussaini Jagaba, Shehu Sa’ad Abdullahi, Elsayed Mohamed Tag-Eldin and Habibun Nabi Muhammad Ekramul Mahmud

Separations 2022, 9(11), 356; https://doi.org/10.3390/separations9110356 - 8 Nov 2022

Cited by 34 | Viewed by 3428

Abstract

This work successfully created a polypyrrole-polyethyleneimine (PPy-PEI) nano adsorbent for the elimination of the lead ion Pb²⁺ from an aqueous solution. An efficient conducting polymer-based adsorbent called as was created using ammonium persulfate (NH4)₂S₂O₈ as an oxidant [...] Read more.

This work successfully created a polypyrrole-polyethyleneimine (PPy-PEI) nano adsorbent for the elimination of the lead ion Pb²⁺ from an aqueous solution. An efficient conducting polymer-based adsorbent called as was created using ammonium persulfate (NH4)₂S₂O₈ as an oxidant (PPy-PEI). The PEI hyper-branched polymer with terminal amino groups was added to the PPy adsorbent to offer heavy metals more effective chelating sites. Pb²⁺ removal from aqueous solution using polyethyleneimine micro adsorbent was successfully accomplished using a batch equilibrium technique (PPy-PEI). The generated water-insoluble polymer nanoadsorbent had enough nitrogen atoms; therefore, an effort was made to link PEI, a water-soluble PPy, with PPy, a conjugated polymer, for lead ion adsorption from an aqueous solution. The generated PPy-PEI nanoadsorbents were discovered to have average particle sizes of 18–34 nm and a Brunauer-Emmet-Teller surface area of 17 m²/g, respectively. The thermal behavior of the composites was investigated using thermo gravimetric and differential scanning calorimetric methods. The lead ion adsorption efficacy of pure polypyrrole was found to be 38%; however, a batch equilibrium technique employing nanoadsorbent revealed with the maximum adsorption capacity of 75.60 mg g⁻¹. At pH 10 and 30 min of contact time at 50 °C, 0.2 g of adsorption was shown to be the ideal dosage. X-ray diffraction analysis, energy-dispersive ray spectroscopy, and Fourier transform infrared ray spectrum support the lead ion adsorption by PPy-PEI nanoadsorbents. The cauli-like structure was visible using field emission scanning electron microscopy. Studying the thermodynamic showed that the adsorption was endothermic as illustrated from the positive value of value of ΔH° is 1.439 kJ/mol which indicates that the uptake of Pb²⁺ onto nanoadsorbent PPy-PEI could be attributed to a physical adsorption process. According to the values of ΔG°, the adsorption process was spontaneous at all selected temperatures. The positive value of ΔS° value (43.52 j/mol) suggested an increase in the randomness at the solid/solution interface during the adsorption process. The adsorption data meet the pseudo-second-order kinetic model and suited the Langumuir isothermal model effectively. Full article

(This article belongs to the Special Issue Separation Technologies in Water and Wastewater Treatment and Resources Recovery)

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16 pages, 2294 KiB

Open AccessArticle

Extraction, Separation and Purification of Bioactive Anticancer Components from Peganum harmala against Six Cancer Cell Lines Using Spectroscopic Techniques

by Huma Mehreen Sadaf, Yamin Bibi, Samha Al Ayoubi, Naila Safdar, Ahmad Sher, Darima Habib, Sobia Nisa, Khafsa Malik, Sunjeet Kumar, Waseem Ahmed and Abdul Qayyum

Separations 2022, 9(11), 355; https://doi.org/10.3390/separations9110355 - 7 Nov 2022

Cited by 4 | Viewed by 2641

Abstract

Conventional cancer treatments normally involve chemotherapy or a combination of radio- and chemotherapy. However, the adverse effects of synthetic medicines encouraged the exploration of novel therapeutic medications of a bio-friendly nature. In an effort to explore anticancer compounds from natural resources, crude extract [...] Read more.

Conventional cancer treatments normally involve chemotherapy or a combination of radio- and chemotherapy. However, the adverse effects of synthetic medicines encouraged the exploration of novel therapeutic medications of a bio-friendly nature. In an effort to explore anticancer compounds from natural resources, crude extract of Peganum harmala (seeds) was fractionated on the basis of polarity, and the fractions were further tested for anticancer activity. Brine shrimp lethality assays and potato disc antitumor assays were used to test each fraction for cytotoxic and antitumor potential. The ethyl acetate fraction was found to be most potent, with LC₅₀ and IC₅₀ values of 34.25 µg/mL and 38.58 µg/mL, respectively. Further activity-guided fractionation led to the isolation of the bioactive compound PH-HM-10 which was identified and characterized by Mass Spectroscopy (MS), Infrared Spectroscopy (IR), Proton Nuclear Magnetic Resonance Spectroscopy (¹HNMR), Carbon Nuclear Magnetic Resonance Spectroscopy (¹³CNMR) and Heteronuclear Single Quantum Correlation (HSQC). Anticancer aspects in the isolated compound were determined against six human cancer cell lines with a maximum anticancer effect (IC₅₀ = 36.99 µg/mL) against the tested human myeloid leukemia (HL-60) cell line, followed by the human lung adenocarcinoma epithelial cell line (A549) and the breast cancer cell line (MCF-7) with an IC₅₀ of 63.5 µg/mL and 85.9 µg/mL, respectively). The findings of the current study suggest that the isolated compound (Pegaharmine E) is significantly active against the tested cancer cell lines and can be further investigated to develop future novel anticancer chemotherapeutic agents. Full article

(This article belongs to the Special Issue Separation, Extraction and Purification of Natural Products)

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Separations, Volume 9, Issue 11 (November 2022) – 61 articles

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