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

• Main Authors: Fabiano A. S. Oliveira, Fernando D. Madureira, Renata P. Lopes, Marina G. Ferreira, Benito Soto-Blanco, Marília M. Melo
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 2014-01-01
• Series: Química Nova
• Subjects: pesticides; milk; multiresidue analysis; mass spectrometer
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422014001000020&lng=en&tlng=en

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%.