A fully automated LC/MS method development and quantification protocol targeting 52 carbamates, thiocarbamates, and phenylureas.

Abstract

We have developed a fully automated LC/MS method development and quantification protocol targeting 52 carbamtes, thiocarbamates, and phenylureas. This is a simple LC/MS method with direct injection; no post-column derivatization was required. The method utilized the Waters Alliance HT Chromatography System and the Waters ZQ 2000 mass spectrometer. System control and data processing was by MassLynx 4.0 with QuanLynx Application Manager. Analyte separation was accomplished by Waters Symmetry reversed-phase C8 column. An ammonium acetate water/acetonitrile binary gradient was used for the separation. The MS multichannel ability minimized the LC method development time with less demand on chromatographic peak resolution. Quantification results were obtained for 46 analytes out of the 52 targets. The coefficients of determination ranged from 0.886 to 0.999. The automated LC/MS protocol has sufficient sensitivity to accommodate the current EPA requirements. The limits of detection (3 times the S/N) ranged from 0.091 to 19.3 ng/mL with 50-microL injection. The highly selective MS detector enabled the matrix effect to be minimized. This method was applied to local drinking water and wastewater samples. Each matrix was spiked with the 52 target analytes at 2 and 20 ng/mL. The recoveries were within the EPA acceptance range.