title: Accurate mass analysis of ethanesulfonic acid degradates of acetochlor and alachlor using high-performance liquid chromatography and time-of-flight mass spectrometry.
abstract: Degradates of acetochlor and alachlor (ethanesulfonic acids, ESAs) were analyzed in both standards and in a groundwater sample using high-performance liquid chromatography-time-of-flight mass spectrometry with electrospray ionization. The negative pseudomolecular ion of the secondary amide of acetochlor ESA and alachlor ESA gave average masses of 256.0750+/-0.0049 amu and 270.0786+/-0.0064 amu respectively. Acetochlor and alachlor ESA gave similar masses of 314.1098+/-0.0061 amu and 314.1153+/-0.0048 amu; however, they could not be distinguished by accurate mass because they have the same empirical formula. On the other hand, they may be distinguished using positive-ion electrospray because of different fragmentation spectra, which did not occur using negative-ion electrospray.
authors.affiliation: U.S. Geological Survey, Lawrence, KS 66049, USA. ethurman@usgs.gov
authors.forename: E M
authors.initials: EM
authors.lastname: Thurman
authors.forename: Imma
authors.initials: I
authors.lastname: Ferrer
authors.forename: Rick
authors.initials: R
authors.lastname: Parry
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D000476:Alkanesulfonates / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006540:Herbicides / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D014052:Toluidines / Q000737:chemistry*
chemical_list: D000081:Acetamides; D000476:Alkanesulfonates; D006540:Herbicides; D014052:Toluidines; C000188:alachlor; C002634:ethane sulfonate; C043377:acetochlor