Quantification of the new triketone herbicides, sulcotrione and mesotrione, and other important herbicides and metabolites, at the ng/l level in surface waters using liquid chromatography-tandem mass spectrometry.
The LC/ESI/MSMS method allows the trace quantification (ng/l) of the new triketone herbicides, i.e. sulcotrione and mesotrione, and important herbicides and metabolites, in natural waters. Solid phase extraction (SPE) for sample enrichment is performed with OASIS (recoveries 94-112% for parent herbicides). Neutral and acidic compounds were analyzed separately with ESI in positive and negative mode, respectively. Quantification limits varied between 0.5 and 10 ng/l. The acidic herbicides detection was improved by a neutralizing post-column addition solution. The influence of ion suppression on quantification is discussed in detail. It is shown that we could overcome this problem and achieve reliable quantification using isotope labeled internal standards (ILIS) for every single analyte. The methods performance is illustrated with samples from a lake depth profile.
Freitas
Luciana Gomides
LG
Swiss Federal Institute for Environmental Science and Technology (EAWAG), Uberlandstrasse 133, CH-8600 Dübendorf, Switzerland.
Götz
Christian W
CW
Ruff
Matthias
M
Singer
Heinz P
HP
Müller
Stephan R
SR
D002851:Chromatography, High Pressure Liquid; D003512:Cyclohexanones / Q000032:analysis*; D005618:Fresh Water / Q000032:analysis; D006540:Herbicides / Q000032:analysis*; D013058:Mass Spectrometry; D008698:Mesylates / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis; D015203:Reproducibility of Results; D014874:Water Pollutants, Chemical / Q000032:analysis*
D003512:Cyclohexanones; D006540:Herbicides; D008698:Mesylates; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; C432907:mesotrione; C079906:sulcotrione