LC/MS Analysis of 4-Methoxy-6-methyl-1,3,5-triazin-2-yl-Containing Sulfonylurea Herbicides in Soil

A multiresidue method for the determination of chlorsulfuron, metsulfuron-methyl, thifensulfuron-methyl, and triasulfuron in soil by high-performance liquid chromatography/electrospray/mass spectrometry (LC/ES/MS) is reported. A clay loam soil, spiked at 6.0 μg kg - 1 with all four herbicides, was extracted with 0.1 M ammonium carbonate, and the extract was cleaned up by C 18 -SPE. The herbicides were quantified using selected ion monitoring. The percent recoveries were as follows: chlorsulfuron, 80.1 ± 7.9%; metsulfuron-methyl, 99.4 ± 8.6%; thifensulfuron-methyl, 95.9 ± 5.9%; and triasulfuron 100.5 ± 24.3%. We have shown that we can analyze and confirm four 4-methoxy-6-methyl-1,3,5-triazin-2-yl-containing sulfonylurea herbicides in soil by LC/ES/MS. This multiresidue method should also be appropriate for other sulfonylurea and polar herbicides.