Simultaneous Determination of 18 Amide Herbicides in Surface Water by SPE-UPLC-MS/MS

An analytical method of UPLC-MS/MS combined with solid phase extraction (SPE) was developed for simultaneous determination of 18 amide herbicides in surface water. The samples were extracted on an Oasis HLB SPE column with a mixture of acetone and hexane as eluant. Phenanthrene-D10 used as the internal standard was added into the eluent. The analytes were separated on a reverse ACQUITY UPLCTM BEH C18 chromatographic column with a mixture of water and acetonitrile as the mobile phases for gradient elution. ESI and MRM were adopted in MS analysis. Linear relationships were found between the peak areas and the mass concentrations of 18 amide heribicides in defined ranges, with detection limits (3S/N) in the range of 0.4-8.0 ng·L-1, and lower limits of determination in the range of 1.0-10 ng·L-1. Recovery rates obtained by standard addition method were in the range of 80.1%-109% and RSDs (n=6) were in the range of 9.6%-15%.