Determination of benzoylurea insecticides in food by pressurized liquid extraction and LC-MS

J Sep Sci. 2010 Jan;33(1):1-10. doi: 10.1002/jssc.200900314.

Abstract

A method based on pressurized liquid extraction and LC-MS/MS has been developed for determining nine benzoylureas (BUs) in fruit, vegetable, cereals, and animal products. Samples (5 g) were homogenized with diatomaceous earth and extracted in a 22 mL cell with 22 mL of ethyl acetate at 80 degrees C and 1500 psi. After solvent concentration and exchange to methanol, BUs were analyzed by LC-MS/MS using an IT mass analyzer, which achieved several transitions of precursor ions that increase selectivity providing identification. LOQs were between 0.002 and 0.01 mg/kg, which are equal or lower than maximum residue limits established by the Codex Alimentarius. Excellent linearity was achieved over a range of concentrations from 0.01 to 1 mg/kg with correlation coefficients 0.995-0.999 (n=7). Validation of the total method was performed by analyzing in quintuplicate seven different commodities (milk, eggs, meat, rice, lettuce, avocado, and lemon) at three concentration levels (0.01, 0.1, and 1 mg/kg). The recoveries ranged from 58 to 97% and the RSDs from 5 to 19% depending on the compound and the commodity. The combination of pressurized liquid extraction with LC-MS/MS provides a sensitive and selective method for the determination of BUs in food.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromatography, Liquid / methods*
  • Food Contamination / analysis*
  • Fruit / chemistry
  • Insecticides / analysis*
  • Limit of Detection
  • Mass Spectrometry / methods*
  • Meat / analysis
  • Methylurea Compounds / analysis*
  • Molecular Structure
  • Pesticide Residues / analysis
  • Reproducibility of Results
  • Solvents / chemistry
  • Vegetables / chemistry

Substances

  • Insecticides
  • Methylurea Compounds
  • Pesticide Residues
  • Solvents