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United States Department of Agriculture

Agricultural Research Service

Title: Application of Analyte Protectants to Improve Accuracy and Ruggedness of Routine Gc-Ms Analysis of Multiple Pesticide Residues in Food Matrices

item Mastovska, Katerina - INST. OF CHEM. TECH.
item Lehotay, Steven
item Anastassiades, Michelangelo - CVUA STUGGART GERMANY

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 4, 2003
Publication Date: June 10, 2004
Citation: Mastovska, K., Lehotay, S.J., Anastassiades, M. 2004. Application of analyte protectants to improve accuracy and ruggedness of routine gc-ms analysis of multiple pesticide residues in food matrices. Meeting Abstract.

Technical Abstract: Essentially, analyte protectants are compounds that strongly interact with active sites in the gas chromatographic (GC) system, thus decreasing degradation and/or adsorption of co-injected analytes. Therefore, the application of analyte protectants can minimize losses of susceptible analytes and significantly improve their peak shapes (due to reduction of peak tailing). When added to both sample extracts and matrix-free standards, analyte protectants can induce an even response enhancement in both instances, resulting in effective equalization of the matrix-induced response enhancement effect. This approach offers a convenient solution to the problems associated with calibration in routine GC analysis of pesticide residues in diverse food samples. Various combinations of compounds, previously identified as potential analyte protectants, were evaluated, and a mixture of 3-O-ethylglycerol, gulonolactone, and sorbitol (10, 1, and 1 mg/mL, respectively, in acetonitrile extracts) was found to be one of the most effective combinations. Not only did the addition of these analyte protectants effectively compensate for the matrix-induced response enhancement, it also performed very well in terms of ruggedness even after more than 150 GC injections, including 130 samples with analyte protectants and 70 matrix (mixed fruit or vegetable) extracts. These protecting agents improved intensity and peak shape of those pesticides susceptible to losses and peak tailing, thus decreasing their detection limits. Moreover, they also minimized the matrix-induced diminishment effect, resulting in improved ruggedness and, consequently, reduced need for frequent GC system maintenance.

Last Modified: 4/20/2014
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