OPTIMIZATION OF CHROMATOGRAPHIC CONDITIONS AND COMPARISON OF EXTRACTION EFFICIENCIES OF FOUR DIFFERENT METHODS FOR DETERMINATION AND QUANTIFICATION OF PESTICIDE CONTENT IN BOVINE MILK BY UFLC-MS/MS

• Published in: Química Nova 2014, Vol.37 (10), p.1699-1706
• Main Authors: Oliveira, Fabiano A. S., Madureira, Fernando D., Lopes, Renata P., Ferreira, Marina G., Soto-Blanco, Benito, Melo, Marília M.
• Format: Article
• Language: English
• Subjects: CHEMISTRY, MULTIDISCIPLINARY; mass spectrometer; milk; multiresidue analysis; pesticides
• ISSN: 0100-4042; 1678-7064
• DOI: 10.5935/0100-4042.20140264

This paper describes the optimization of a multiresidue chromatographic analysis for the identification and quantification of 20 pesticides in bovine milk, including three carbamates, a carbamate oxime, six organophosphates, two strobilurins, a pyrethroid, an oxazolidinedione, an aryloxyphenoxypropionate acid/ester, a neonicotinoid, a dicarboximide, and three triazoles. The influences of different chromatographic columns and gradients were evaluated. Furthermore, four different extraction methods were evaluated; each utilized both different solvents, including ethyl acetate, methanol, and acetonitrile, and different workup steps. The best results were obtained by a modified QuEChERS method that lacked a workup step, and that included freezing the sample for 2 hours at -20 ºC. The results were satisfactory, yielding coefficients of variation of less than 20%, with the exception of the 50 µg L-1 sample of famoxadone, and recoveries between 70 and 120%, with the exception of acephate and bifenthrin; however, both analytes exhibited coefficients of variation of less than 20%.