Direct Determination of Atrazine Residue on Chinese Cabbage Leaf Using Desorption Electrospray Ionization-Tandem Mass Spectrometry and Its Application for Diagnosing Atrazine Drift Phytotoxicity

A method was developed for the determination of atrazine residue and phytotoxicity on a nontargeted plant, the Chinese cabbage. The analysis was done by desorption electrospray ionization combined with ion trap MS/MS. Within the range of 63.13 to 2525 pg/mm2 of atrazine on the specimen, the linear relationship of the average peak area of extracted product ion m/z 174 (y) versus the surface concentration of atrazine (x) was estimated as y 5066.5x 85779; r was 0.9994, with RSD between 3.37 and 26.17. The LOQ of atrazine on the leaf surface was lower than 63.13 pg/mm2. The method is highly applicable to detect atrazine residue and evaluate atrazine phytotoxicity on Chinese cabbage leaf with good accuracy, selectivity, sensitivity, and specificity.