Evaluation of analytical methods for determining pesticides in baby food

Three extraction methods and two detection techniques for determining pesticides in baby food were evaluated. The extraction techniques examined were supercritical fluid extraction (SFE), enhanced solvent extraction (ESE), and solid phase extraction (SPE). The detection techniques used were enzyme-linked immunosorbent assay (ELISA) and gas chromatography/mass spectrometry (GC/MS). Different SFE and ESE conditions were considered, and the resulting extracts were analyzed by either ELISA or GC/MS. The use of C-18 SPE cartridges to extract pesticides from baby food was also evaluated. Using SFE-ELISA, recoveries of most spiked pesticides were less than 50% in both non-fat and fatty baby food. Using SFE-GC/MS, recoveries of target pesticides were greater than 80% in dried baby food, but 10-60% of the spiked pesticides were lost during the freeze-drying process. Off-Line coupling of SPE-GC/MS provided a quantitative measure (>80%) of the pesticides in non-fat baby food (fruits and vegetables). Direct ELISA applied to diluted non-fat food also gave a quantitative measure of the target pesticides. The ESE-ELISA method provided a quantitative determination of atrazine in both non-fat and fatty baby food. (C) 1999 Elsevier Science B.V. All rights reserved.