DETERMINATION OF ACIDIC HERBICIDES USING LIQUID-CHROMATOGRAPHY WITH PNEUMATICALLY ASSISTED ELECTROSPRAY-IONIZATION MASS-SPECTROMETRIC AND TANDEM MASS-SPECTROMETRIC DETECTION
B. Koppen et Nh. Spliid, DETERMINATION OF ACIDIC HERBICIDES USING LIQUID-CHROMATOGRAPHY WITH PNEUMATICALLY ASSISTED ELECTROSPRAY-IONIZATION MASS-SPECTROMETRIC AND TANDEM MASS-SPECTROMETRIC DETECTION, Journal of chromatography, 803(1-2), 1998, pp. 157-168
Citations number
10
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Liquid chromatography-pneumatically assisted electrospray mass spectro
metry with negative ionization has been used for the determination of
acidic herbicides in ground water. Eighteen pesticides or pesticide de
gradation products belonging to several different groups of acidic her
bicides (phenoxy acids, sulfonylureas, phenols, etc.) were covered in
the study. Optimization of electrospray inlet conditions is described
as well as results from investigations of the linearity of the detecto
r response. Conditions for tandem mass spectrometry (MS-MS) detection
of characteristic daughter ions formed by collision-induced dissociati
on (CID) of the parent ion are described and a comparison of obtainabl
e instrument detection limits by single MS and MS-MS was made. Detecti
on limits using MS in the selected ion monitoring (SIM) mode were gene
rally in the order of 1 mu g/l or below, whereas detection limits were
three-four times higher using MS-MS detection. A principle of analysi
s is proposed based on single quadrupole MS as a method for quantitati
ve determination followed by verification of positive findings by CID
MS-MS. Application of the method for detecting acidic herbicides resid
ues in a ''real-world'' ground water sample is demonstrated. (C) 1998
Elsevier Science B.V.