Simultaneous determination of residual agricultural chemicals in food by GC-MS/MS - Sensitivity of standard solution 1ppb and linearity of calibration curve-

Sample and Method

A pesticide standard solution from FUJIFILM Wako Pure Chemical Corporation (PL series) was used that consisted of equal amounts of PL 1, 2, 3, 4, 5, 6, 11, and 12. Afterwards, the solution was diluted to 1, 5, 10, 50 and 100 ppb. PEG 300 was used to protect the pesticides from thermal decomposition in the GC injection liner. In this work, both the sensitivity and the linearity of the calibration curve were examined for 150 pesticides. Table 1 shows the measurement conditions used for the analysis.

Table 1 Measurement condition

[GC-TQMS condition]

Results and Discussion

Figure 1 shows the calibration curves from 1-100ppb as well as the SRM chromatograms for 4 pesticides at 1ppb. The JMS-TQ4000GC showed excellent linearity and sensitivity for this range of concentrations. Fig 2 shows the retention times (R.T.), SRM information, and correlation coefficient for 150 pesticide calibration curves. Since the uniform criterion of the positive list system is 10 ppb, when the concentration ratio in the sample pretreatment is equal, the criteria concentration in the measurement sample for GC-MS/MS is also 10 ppb. A number of pesticides were detected with good sensitivity at 1 ppb which is 1/10 of criteria concentration. These results suggest that the JMS-TQ4000GC is the most effective tool for pesticide analysis.

Fig.1 　Calibration curves (1-100ppb) and SRM chromatograms for 1ppb data

Table 2 Calibration curve information for 150 pesticides using 1, 5, 10, 50 and 100 ppb standard solutions (n=3 each)

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