Multiresidue analysis and monitoring of pesticides in rice by pressurized liquid extraction

Abstract

The aim of this study was to assess the performance of a method of analyzing pesticides in rice by using pressurized liquid extraction (PLE) and to perform a preliminary monitoring by using that method. The instrumental quantification limit, instrumental detection limit, method quantification limit, and method detection limit were determined. PLE temperature was also optimized for 6 target pesticides. Mean recoveries of spiked rice with target pesticides (4 ng/g and 40 ng/g) were 83%–109% with the repeatability of the analysis, represented as relative standard deviations, ranged from 1.3% to 11% (n = 5) for PLE at 130°C. These results were satisfactory according to the method of positive list in Japan. In a preliminary analysis of 10 target pesticides in 54 commercial rice samples, ferimzone was detected in only one unpolished rice sample.

Keywords:

• Pressurized liquid extraction
• pesticide analysis
• pesticide residue
• pesticide monitoring
• rice

Acknowledgments

This work was supported by KAKENHI (Grant-in-Aid for Young Scientists (Start-up), No. 19890282).

Notes

^a The precision is indicated as relative standard deviation (RSD) (n = 4).

^b The absolute amount of analyte that gives a signal-to-noise ratio (S/N) = 10.

^c The absolute amount of analyte that gives S/N = 3.

^d 3 × MDL.

^e The minimum concentration that can be detected in a sample.