Analytica

17 pages, 3181 KiB

Open AccessArticle

Development of Noninvasive Method for the Automated Analysis of Nine Steroid Hormones in Human Saliva by Online Coupling of In-Tube Solid-Phase Microextraction with Liquid Chromatography–Tandem Mass Spectrometry

by Takashi Hitomi and Hiroyuki Kataoka

Analytica 2024, 5(2), 233-249; https://doi.org/10.3390/analytica5020015 - 9 May 2024

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Abstract

Accurate measurement of steroid hormones is crucial to elucidate new mechanisms of action and diagnose steroid metabolism-related diseases. This study presents a simple, sensitive, and automated analytical method for nine representative steroid hormones. The method involves on-line coupling of in-tube solid-phase microextraction (IT-SPME) [...] Read more.

Accurate measurement of steroid hormones is crucial to elucidate new mechanisms of action and diagnose steroid metabolism-related diseases. This study presents a simple, sensitive, and automated analytical method for nine representative steroid hormones. The method involves on-line coupling of in-tube solid-phase microextraction (IT-SPME) with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The steroid hormones were extracted and enriched on a Supel-Q PLOT capillary column using IT-SPME. Subsequently, they were separated and detected within 6 min using a Discovery HS F5-3 column and positive ion mode multiple reaction monitoring system via LC–MS/MS. Calibration curves of these compounds using each stable isotope-labeled internal standard (IS) showed linearity with correlation coefficients greater than 0.9990 in the range of 0.01–40 ng/mL, with limits of detection (S/N = 3) of 0.7–21 pg/mL. Moreover, intra- and inter-day variations were lower than 8.1 and 15% (n = 6), respectively. The recoveries of these compounds from saliva samples were in the range of 82–114%. The developed IT-SPME/LC–MS/MS method of steroid hormones is a highly sensitive, specific, and non-invasive analytical method that allows extraction and enrichment with no organic solvents, and enables direct automated online analysis by simply ultrafiltrating a small sample of saliva. Full article

(This article belongs to the Section Sample Pretreatment and Extraction)

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14 pages, 2081 KiB

Open AccessArticle

Quantification of Recycled PET in Commercial Bottles by IR Spectroscopy and Chemometrics

by Alessandro Zappi, Alessandra Biancolillo, Nicholas Kassouf, Valentina Marassi, Pietro Morozzi, Laura Tositti and Dora Melucci

Analytica 2024, 5(2), 219-232; https://doi.org/10.3390/analytica5020014 - 8 May 2024

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Abstract

A novel approach for the quantification of recycled polyethylene terephthalate (r-PET) in commercial bottles is presented. Fifty-eight bottle samples from several brands and producers containing different percentages of r-PET were purchased from the market. Samples were analyzed by two spectroscopic methods: near-infrared (NIR) [...] Read more.

A novel approach for the quantification of recycled polyethylene terephthalate (r-PET) in commercial bottles is presented. Fifty-eight bottle samples from several brands and producers containing different percentages of r-PET were purchased from the market. Samples were analyzed by two spectroscopic methods: near-infrared (NIR) spectroscopy and attenuated total reflection (ATR) spectroscopy in the mid-infrared (MIR) region. No chemical pre-treatment was applied before analyses. The spectra were analyzed by partial-least squares (PLS) regression, and two models for NIR and MIR data were computed. Then, a multi-block regression was applied to join the two datasets. All models were validated by cross-validation and by excluding and projecting onto the model the replicated spectra of one sample at a time. Results demonstrated the potential of this approach, especially considering the variability of commercial samples in terms of additives, shape, or thickness of the bottles: for samples close to the centroids of the models (i.e., from 10 to 50% r-PET), the predictions of multi-block method seldom departed from the expected values of ±10%. Only for samples with 0% declared r-PET, the models showed poor prediction abilities. Full article

(This article belongs to the Section Chemometrics)

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16 pages, 3469 KiB

Open AccessArticle

Treatment of Water Contaminated by Ship Oil: Study of Adsorption in a Fixed-Bed Column

by Rachel de M. Ferreira, Bernardo Dia Ribeiro, Danielle M. A. Stapelfeldt and Maria de F. R. Moreira

Analytica 2024, 5(2), 203-218; https://doi.org/10.3390/analytica5020013 - 1 May 2024

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Abstract

Aquatic macrophytes like Salvinia sp. have rapid proliferation and a great capacity for ecological adaptation. In addition to these characteristics, this study points to their ability to adsorb contaminants such as dyes, metals, and oils. This work aims, through an adsorption study, to [...] Read more.

Aquatic macrophytes like Salvinia sp. have rapid proliferation and a great capacity for ecological adaptation. In addition to these characteristics, this study points to their ability to adsorb contaminants such as dyes, metals, and oils. This work aims, through an adsorption study, to propose an alternative treatment using chemically modified Salvinia sp. (SOH) biomass to remove oil from water. Batch adsorption experiments were performed to observe the effects of concentration, pH, time, temperature, desorption, and reuse of the biomass. The adsorption mechanisms, performance, kinetics, isotherm, thermodynamics, and reusability of biomass were evaluated. Both adsorbents were well-defined by the Freundlich model isotherm. According to the results obtained, the q_max was 898.0 mg g⁻¹ for SOH in oil-in-salt water emulsion in 15 min and 930.59 mg g⁻¹ for Salvinia sp. in natura (SS) in the oil-in-water emulsion. In the fixed-bed column adsorption, the adsorption capacity was 2.99 g g⁻¹ for SS and 3.49 g g⁻¹ for SOH, and the saturation capacity was 42.89 g g⁻¹ SS and 42.99 g g⁻¹ SOH. According to the adsorption models, the Bohart–Adams model best fits the experimental data of this study. The SOH adsorbed oil recovery test was successful, with 100% oil recovery. Full article

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16 pages, 320 KiB

Open AccessReview

Poly- and Perfluoroalkyl Substance (PFAS) Analysis in Environmental Matrices: An Overview of the Extraction and Chromatographic Detection Methods

by Alessia Iannone, Fabiana Carriera, Cristina Di Fiore and Pasquale Avino

Analytica 2024, 5(2), 187-202; https://doi.org/10.3390/analytica5020012 - 19 Apr 2024

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Abstract

Per- and polyfluoroalkyl substances (PFASs) are carbon–fluorine compounds with widespread industrial and domestic use, posing potential toxicological risks to humans and ecosystems. Several analytical methods have been developed to assess the occurrence of PFASs in the environment, but a standardized method, applicable to [...] Read more.

Per- and polyfluoroalkyl substances (PFASs) are carbon–fluorine compounds with widespread industrial and domestic use, posing potential toxicological risks to humans and ecosystems. Several analytical methods have been developed to assess the occurrence of PFASs in the environment, but a standardized method, applicable to all matrices, is still lacking. This paper reviews the extraction and chromatographic detection methods for PFAS assessment in environmental samples, considering parameters such as the LOD, LOQ, and recoveries. Solid phase extraction (SPE) is commonly used, showing high recovery rates for water, soil, and sediment samples using HBL and WAX polymeric sorbents (85–100% and 93–111.5%, respectively). LC-MS has demonstrated low LODs and LOQs in seawater (0.01–0.08 ng L⁻¹; 0.03–0.24 ng L⁻¹), marine sediment (0.002–0.018 ng g⁻¹; 0.004–0.054 ng g⁻¹), and dust (0.08–0.68 pg g⁻¹; 0.26–2.25 pg g⁻¹), indicating its sensitivity when detecting trace PFAS levels. Evaluating PFASs is crucial for the development of future removal strategies and risk assessments. Potential solutions including the use of PFAS substitutes and innovative adsorption techniques for their adsorption could present promise in reducing their environmental presence. Full article

(This article belongs to the Section Chromatography)

17 pages, 2647 KiB

Open AccessArticle

A Metabolomics Study by ¹H HRMAS NMR: From Sheep Milk to a Pressed-Curd Cheese: A Proof of Concept

by David Castejón, José Segura, Karen Paola Cruz-Díaz, Víctor Remiro, María Encarnación Fernández-Valle, María Dolores Romero de Ávila, Palmira Villa and María Isabel Cambero

Analytica 2024, 5(2), 170-186; https://doi.org/10.3390/analytica5020011 - 13 Apr 2024

Viewed by 654

Abstract

For the first time, High-Resolution Magic Angle Nuclear Magnetic Resonance spectroscopy (NMR-HRMAS) was applied to directly identify specific metabolites from a Spanish raw ewe’s milk and enzymatic coagulation pressed-curd cheese (Protected Geographical Indication: Castellano) manufactured by two procedures (traditional/artisanal vs. industrial) and [...] Read more.

For the first time, High-Resolution Magic Angle Nuclear Magnetic Resonance spectroscopy (NMR-HRMAS) was applied to directly identify specific metabolites from a Spanish raw ewe’s milk and enzymatic coagulation pressed-curd cheese (Protected Geographical Indication: Castellano) manufactured by two procedures (traditional/artisanal vs. industrial) and including the ewe’s raw milk. The NMR parameters were optimized to study the complex matrixes of this type of cheese. In addition, conventional overcrowded ¹H-NMR-HRMAS spectra were selectively simplified by a Carr–Purcell–Meiboom–Gill (CPMG) sequence or a stimulated echo pulse sequence by bipolar gradients (DIFF), thus modulating spin–spin relaxation times and diffusion of molecular components, respectively. ¹H-NMR-HRMAS spectroscopy displayed important information about cheese metabolites, which can be associated with different manufacturing processes (industrial vs. traditional) and ripening times (from 2 to 90 days). These results support that this spectroscopy is a useful technique to monitor the ripening process, from raw milk to commercial ripened cheese, using a minimum intact sample, implying the absence of time-consuming sample pretreatments. Full article

(This article belongs to the Collection Analytical and Applied Chemistry: the challenges and opportunities for growth in the 21st century)

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17 pages, 3782 KiB

Open AccessArticle

Headspace-Selected Ion Flow Tube Mass Spectrometry Workflows for Rapid Screening and Quantitation of Hazardous Volatile Impurities in Personal Care Products

by Mark J. Perkins, Colin J. Hastie and Vaughan S. Langford

Analytica 2024, 5(2), 153-169; https://doi.org/10.3390/analytica5020010 - 2 Apr 2024

Viewed by 513

Abstract

Personal care products (PCPs) are intended for regular application by consumers and therefore assuring the safety of these products is very important. Recently, benzene contamination has been highlighted in certain PCPs. The present study applies selected ion flow tube mass spectrometry (SIFT-MS) to [...] Read more.

Personal care products (PCPs) are intended for regular application by consumers and therefore assuring the safety of these products is very important. Recently, benzene contamination has been highlighted in certain PCPs. The present study applies selected ion flow tube mass spectrometry (SIFT-MS) to a simultaneous headspace analysis of benzene, 1,4-dioxane, and formaldehyde—all known or suspected carcinogens—in nine haircare products with supporting qualitative analysis by gas chromatography–mass spectrometry (GC-MS). Headspace-SIFT-MS method development is compatible with the method of standard additions, which is necessary for the quantitation of volatile impurities in these complex emulsions. Benzene was quantified above the low-ng g⁻¹ limit of quantitation (LOQ) in three products, dioxane above the sub-μg g⁻¹ LOQ in all products, and formaldehyde above the low-μg g⁻¹ LOQ in two products, providing a quantitative analysis at concentrations relevant to consumer safety. This study facilitated the development of generic workflows for SIFT-MS method development and application in routine analysis of PCPs. The assessment of workflows for SIFT-MS compared to a conventional GC-MS analysis suggests that 8- to 30-fold throughput enhancements may be possible for quantitative and screening analysis using SIFT-MS. Full article

(This article belongs to the Collection Analytical and Applied Chemistry: the challenges and opportunities for growth in the 21st century)

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Analytica, Volume 5, Issue 2 (June 2024) – 6 articles

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