Optimization and Selection of Mobile Phase for the Determination of Multiple Pesticide Standards Using Liquid Chromatography-Tandem Mass Spectrometry

Authors : Abubakar LAWAL, Richard Chee Seng WONG

Pages : 263-278

Doi:10.18596/jotcsa.778786

View : 10 | Download : 13

Publication Date : 2021-02-28

Article Type : Research Paper

Abstract :The selection of the best mobile phase setup is one of the most important factors to be considered prior to quantitative instrumentation of multiple pesticides. Usually, mobile phases comprises of water insert ignore into journalissuearticles values(A); and an organic solvent insert ignore into journalissuearticles values(B); are the setup used in liquid chromatography instruments for the analysis of pesticide residues in various samples. Unfortunately, most of the analysis are being carried out without optimization and selection of the best mobile phase setup to improve the sensitivity of the instrument. For that reason, the comparative analysis of the reportedly used mobile phases and some few suggested ones was carried out on the multi-pesticide mixture of 0.1 mg/kg insert ignore into journalissuearticles values(100 µg/kg); standard solutions and quantified with liquid chromatography-tandem mass spectrometry insert ignore into journalissuearticles values(LC-MS/MS); instrument. Consequently, the best mobile phases setup that resulted in the sum of average total chromatographic peak areas insert ignore into journalissuearticles values(ATCPAs); and average total chromatographic peak heights insert ignore into journalissuearticles values(ATCPH); for the total ion chromatography insert ignore into journalissuearticles values(TIC); scans as an index that correspond to the concentration levels was selected [0.1 % formic acid in H2O insert ignore into journalissuearticles values(A); and 0.1 % formic acid in acetonitrile insert ignore into journalissuearticles values(ACN); insert ignore into journalissuearticles values(B);]. And further optimization was successfully carried out on the selected mobile phase A and the resulted setup [1 % ACN and 0.1 % formic acid in Milli-Q-water insert ignore into journalissuearticles values(mobile phase A); coupled with 0.1 % formic acid in ACN insert ignore into journalissuearticles values(mobile phase B);] improved the instrumental sensitivity on the targeted analytes. Thus, this justify the potential benefits of optimizing setup of the mobile phases prior to LC-MS/MS instrumentation of multi-pesticide analytes.
Keywords : Mobile phase, Analysis of multi pesticide residues, Liquid chromatography tandem mass spectrometry, Total ion chromatography, Total chromatographic peak areas