Abstract
The analytical method using frit/fast atom bombardment (FAB)-liquid chromatography/mass spectrometry (LC/MS) was developed for the quantitative determination of nonvolatile and thermolabile pesticides in water. A sample water was passed through a polystyrene solid phase extraction (SPE) cartridge to extract pesticides. The reextraction of the pesticides was performed by back-flushing the cartridge with acetonitlile. The eluate with an addition of 2-phenoxybutyric acid as internal standard was analyzed by frit/FAB-LC/MS-selected ion monitoring (SIM) method without any derivatization procedure as a pretreatment.
The recovery ratio of 11 pesticides (2,4-D, bensultap, MCPA, MCPB, MCPP, mefenacet, methomyl, NAC, thiuram, tricyclazole and pyrazolate) spiked into ground water, river water and tap water were shown a figure such as 70% or more except bensultap for the routine analysis of them. In addition, their coefficient of variation (relative standard deviation) except bensultap ranged from 2.6 to 23.3% at detection limit level. Therefore, we have concluded this analytical method has an advantage to reduce the pretreatment of sample such as derivatization of nonvolatile and thermolabile pesticides.
However, some pesticides such as bensultap, methomyl and thiuram showed less quantitative accuracy, and so it needs further studies such as developing more efficient extraction procedure.
