*2.4. Sample Measurement*

There were five types of pollutant in the GTP category. However, in the analysis of each sample, the identification of microplastics, PAH, and heavy metal contaminants was prioritized, while the identification of pesticide residues and medical waste was not prioritized to limit the publication's scope. However, these two types of contaminants can be viewed, together with PAH, based on GC/MS chromatogram data:


AAS absorption at the maximum wavelength (Pb: λmax. 228.9 nm and Cu: λmax. 324.7 nm) [33,34,80]. The method for determining the pollutant concentrations of Pb+2 and Cu+2 first makes a calibration curve to make ten series of Pb+2 and Cu+2 standard solutions whose estimated sample concentrations fall within the range of the standard solution, then the absorption of each concentration is measured. Then, the standard deviation and slope determination calculations are carried out. The concentration of each sample (Pb+2 and Cu+2) was calculated based on the absorption obtained from AAS after being plotted into the regression equation [22,33,80]. Determination of pollutant concentrations of Pb+2 and Cu+2 carried out measurements of three replications for each type of sample obtained at three different sampling points. The data from the measurement results were calculated on average and summarized in a table. The quality of seawater according to the quality standard for pollutants Pb+2 and Cu+2 is a maximum of 0.05 mg/L. The quality standard for fish and other non-spongy biota is a maximum of 0.008 mg/L [55,76,80–82]. The maximum limit is not specified for sponges because they are included in the category of biota that are not eaten. The maximum limit of Pb+2 and Cu+2 for sediment is 0.10 μg/g. The quality of seawater and fish in BCI is determined by comparing the average pollutant concentration calculated compared to the standard for seawater and fish [4,10,59,83].
