Determination of Multi-Residues and Efficacy of Some Pesticides Newly Registered for Agricultural Products in North Vietnam ☆

A simple and accurate method based on the modification of QuEChERS extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed for determination of residues of some newly registered pesticides for agricultural products in North Vietnam. The residues of seven pesticides were detected and quantified by LC-MS/MS method using 6410 triple quadrupole mass spectrometer coupled to an Agilent LC1100 high performance liquid chromatography system. To minimize the matrix effect, the matrix matched calibration technique was used. The method showed a good performance in the concentrations ranges from 0.001 to 0.16 mg/kg. The LOQ values were lower than 0.01 mg/kg for all pesticides in the tests. Spike recoveries were from 80 to 115% and the repeatability was lower than 7% RSD. Our method has been applied successfully for many types of agricultural products including dragon fruits, tomato, tea, cabbage, cucumber and longan.