| Abstract
| - Due to the great potential of atrazine in contaminatinggroundwater, its use has been banned in several countriesand often replaced by terbuthylazine (CBET). Little isknown on the fate of CBET in soil. The purpose of thiswork has been (1) to develop a general method for analyzingCBET and its degradation products (DPs) in soil and (2)to use this method for elucidating the fate of CBET incubatedin both surface and subsurface samples of an agriculturalsoil which had been receiving repeated CBET spills.This method involves analyte extraction from soil at 100°C by phosphate-buffered water. Analytes coming out of theextraction cell were collected by a graphitized carbonblack extraction cartridge. After analyte elution with asuitable solvent mixture, the final extract was analyzed by LC-MS. From an aged soil, our method extracted altogetherquantities of CBET and its DPs respectively 2.1 and 1.4 timeslarger than those by two previously reported methods.For the analytes considered, limits of quantification (S/N10) ranged between 0.22 and 5.5 ng per gram of soil. Thelaboratory CBET degradation experiment showed that (1)similarly to atrazine, remarkable amounts of hydroxylatedmetabolites were formed; (2) when the subsoil microflorawas in the presence of rather large amounts of CBET, itdegraded the herbicide with a rate similar to that of thetopsoil microflora.
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