Pesticide residue analysis in foodstuffs applying capillary gas chromatography with mass spectrometric detection: State-of-the-art use of modified DFG-multimethod S19 and automated data evaluation

• Published in: Journal of Chromatography A Vol. 892; no. 1; pp. 347 - 377
• Main Author: Stan, Hans-Jürgen
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2000; Elsevier
• Subjects: Analytical chemistry; Automation; Biological and medical sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Evaluation Studies as Topic; Exact sciences and technology; Food Analysis; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Gas chromatographic methods; Gas Chromatography-Mass Spectrometry - methods; Pesticide Residues - analysis; Pesticides; Food analysis; Pesticides; Trace analysis; Automation; Chemical analysis; Liquid liquid extraction; Coupled method; Foodstuff; Fruit vegetable; Solvent extraction; Contamination; Gel permeation chromatography; Gas chromatography; Analysis method; Sample preparation; Residue; Qualitative analysis; Mass spectrometry; Quantitative analysis
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(00)00308-3

This paper focuses on recent developments in the author’s laboratory and reports on the “ultimate” analysis scheme which has evolved over the last 20 years in our laboratory. This demonstrates the feasibility of screening analyses for pesticide residue identification, mainly by full scan GC–MS, down to the 0.01 ppm concentration level in plant foodstuffs. It is based on a miniaturized DFG S19 extraction applying acetone for extraction followed by liquid–liquid extraction with ethyl acetate–cyclohexane followed by gel permeation chromatography. The final chromatographic determination is carried out with a battery of three parallel operating gas chromatographic systems using effluent splitting to electron-capture and nitrogen–phosphorus detection, one with a SE-54 the other with a OV-17 capillary column and the third one with a SE-54 capillary column and mass selective detection for identification and quantitation. The method is established for monitoring more than 400 pesticides amenable to gas chromatography. These pesticide residues are identified in screening analyses by means of the dedicated mass spectral library PEST.L containing reference mass spectra and retention times of more than 400 active ingredients and also metabolites applying the macro program AuPest (Automated residue analysis on Pesticides) for automated evaluation which runs with Windows based HP ChemStation software. The two gas chromatographic systems with effluent splitting to electron-capture and nitrogen–phosphorus detection are used to check the results obtained with the automated GC–MS screening and also to detect those few pesticides which exhibit better response to electron-capture and nitrogen–phosphorus detection than to mass spectrometry in full scan.