Abstract:

The combination of QuEChERS and gas chromatography-mass spectrometry (GC-MS) was employed to establish
a new method for the rapid screening 17 pesticide residues in rice, including dichlorvos, molinate, omethoate, quintozene,
propanil, chlorpyrifos-methyl, fenitrothion, pirimiphos-methyl, malathion, chlorpyrifos, phenthoate, procymidone, butachlor,
isoprothiolane, triazophos, bifenthrin and deltamethrin. Samples were extracted with a mixture of acetonitrile/acetic acid (99:1,
V/V) and salted out with anhydrous MgSO4 and NaCl. After the incorporation of N-propyl ethylenediamine (PSA) and C18 sorbent
for the purification process, GC-MS and NAGINATA™ software were used for the detection and analysis, respectively. The results
showed that the limits of detection (LOD) of the 17 pesticide residues using the established method were in the range of 0.002–
0.050 mg/kg, and their average recovery rates in a blank sample were 80%–110% with relative standard deviations (RSDs) of
1.7%–12.3%. This method was sensitive without the need for any complicated pre-treatments or expensive equipment and was
suitable for the fast screening of pesticide residues in rice. Finally, we adopted the new method to detect pesticide residues in
25 rice samples. The results showed that 3 pesticides including chlorpyrifos, triazophos and isoprothiolane were analyzed, and their
levels were lower than the MRL stipulated by the national standard of China (GB 2763—2014).

Key words: QuEchERS, gas chromatography-mass spectrometry (GC-MS), NAGINATA&trade, software, pesticide residues