Paijens, Claudia, et al. Water, Air, & Soil Pollution, 2020, 231(5), 210.
High performance liquid chromatography-tandem mass spectrometry was used to analyze 18 hydrophilic and hydrophobic biocides in dissolved and particulate fractions of urban and surface water. Three isotopically labeled internal standards (IS, including mecoprop-d3, isoproturon-d6, and terbuthylazine-d5) were used to quantify the target compounds to compensate for any matrix effects or experimental problems. They were added before injection.
Quantification and Quality Control
· Mecoprop-d3 was employed for quantifying mecoprop, the only compound that ionizes in negative mode. To achieve optimal linearity, the other biocides were assigned to the two remaining internal standards. Isoproturon-d6 was utilized for the quantification of BIT, diuron, IPBC, isoproturon, and OIT, while terbuthylazine-d5 was used for benzalkonium compounds (C12-C16), carbendazim, CMIT, DCOIT, cybutryn, MIT, tebuconazole, terbuthylazine, terbutryn, and thiabendazole.
· Calibration curves were generated from spiked standards in a mobile phase (A/B, 80/20, v/v) at concentrations of 0.05, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 10, 25, 75, 150, and 250 μg/L, with 5 μL of internal standard solution added (final concentration of 50 μg/L). The calibration curves were established by calculating the ratio of each standard area to its corresponding internal standard area using quantification transitions. Blanks were injected every 5-6 samples, and a control at 10 μg/L was injected at the beginning, middle, and end of the analytical sequence.
