title: Simultaneous analysis of 70 pesticides using HPlc/MS/MS: a comparison of the multiresidue method of Klein and Alder and the QuEChERS method.
abstract: Since 2003, two new multipesticide residue methods for screening crops for a large number of pesticides, developed by Klein and Alder and Anastassiades et al. (Quick, Easy, Cheap, Effective, Rugged, and Safe; QuEChERS), have been published. Our intention was to compare these two important methods on the basis of their extraction efficiency, reproducibility, ruggedness, ease of use, and speed. In total, 70 pesticides belonging to numerous different substance classes were analyzed at two concentration levels by applying both methods, using five different representative matrixes. In the case of the QuEChERS method, the results of the three sample preparation steps (crude extract, extract after SPE, and extract after SPE and acidification) were compared with each other and with the results obtained with the Klein and Alder method. The extraction efficiencies of the QuEChERS method were far higher, and the sample preparation was much quicker when the last two steps were omitted. In most cases, the extraction efficiencies after the first step were approximately 100%. With extraction efficiencies of mostly less than 70%, the Klein and Alder method did not compare favorably. Some analytes caused problems during evaluation, mostly due to matrix influences.
authors.affiliation: Technical University Dresden, Institute of Food Chemistry, Bergstrasse 66, D-01069 Dresden, Germany. melanie.riedel@bayercropscience.com
authors.forename: Melanie
authors.initials: M
authors.lastname: Riedel
authors.forename: Karl
authors.initials: K
authors.lastname: Speer
authors.forename: Sven
authors.initials: S
authors.lastname: Stuke
authors.forename: Karl
authors.initials: K
authors.lastname: Schmeer
mesh_terms: D002498:Centrifugation; D002851:Chromatography, High Pressure Liquid; D005504:Food Analysis / Q000379:methods* / Q000592:standards*; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D010573:Pesticide Residues / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D012015:Reference Standards; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D007202:Indicators and Reagents; D010573:Pesticide Residues; D010575:Pesticides