JEOL : Simultaneous analysis of pesticides regulated in water supply using gas chromatograph-mass spectrometer

Pesticides in drinking water are subject to simultaneous analysis by solid-phase extraction-gas chromatography-mass spectrometry. In this report, 139 pesticides were analyzed simultaneously, and the linearity of calibration curves and reproducibility were confirmed for 91 components related to the water quality control target items that were applied on April 1, 2022.

Standard solutions were prepared by diluting pesticide mixture standard solutions WQ1, 2, 5, 10 (Fujifilm Wako Pure Chemical Corporation) and others with dichloromethane to concentrations of 1, 5, 10, 50, and 100 µg/L. 9-bromoanthracene, anthracene-d10, and chrysene-d12 were used as internal standards, and added to each standard solution at 50 µg/L. The measurement conditions of the gas chromatograph-mass spectrometer JMS-Q1600GC UltraQuad™ SQ-Zeta used are shown in Table 1.

From the obtained measurement results, the calibration curves and the EIC of 1 µg/L for both chlornitrofen (CNP) and CNP-amino are shown in Fig. 1. Note: The target concentration of CNP (0.1 µg/L) is the total of CNP and CNP-amino conversion concentration. CNP has the lowest target value among the regulated pesticides, and the final concentration of the test solution is extremely low at 0.5 µg/L, even after pretreatment with 500-fold concentration in accordance with the notification method. Although the concentration measured in this report was twice that level, it was detected with sufficient sensitivity, and the linearity of the calibration curve was good.

Figure. 1 Calibration curves (1, 5, 10, 50, 100μg/L) and EIC at 1μg/L concentration of CNP and CNP-amino

The correlation coefficients of the calibration curves at 1, 5, 10, 50, and 100 µg/L and the coefficient of variation for three consecutive measurements of 5 µg/L standard solution are shown in Table 2. For all components, the correlation coefficients of the calibration curves were more than 0.999 and the coefficient of variation at 5 µg/L was less than 10%.

Table. 2 Correlation coefficient of calibration curve, and coefficient of variation at 5μg/L(n = 3), sorted by retention time

* Internal Standard material

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Jeol Ltd. published this content on 18 March 2024 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 18 March 2024 10:14:58 UTC.