Evaluation of analytical methods for determining pesticides in baby food

Three extraction methods and two detection techniques for determining pesti cides in baby food were evaluated. The extraction techniques examined were supercritical fluid extraction (SFE), enhanced solvent extraction (ESE), an d solid phase extraction (SPE). The detection techniques used were enzyme-l inked immunosorbent assay (ELISA) and gas chromatography/mass spectrometry (GC/MS). Different SFE and ESE conditions were considered, and the resultin g extracts were analyzed by either ELISA or GC/MS. The use of C-18 SPE cart ridges to extract pesticides from baby food was also evaluated. Using SFE-E LISA, recoveries of most spiked pesticides were less than 50% in both non-f at and fatty baby food. Using SFE-GC/MS, recoveries of target pesticides were greater than 80% in d ried baby food, but 10-60% of the spiked pesticides were lost during the fr eeze-drying process. Off-Line coupling of SPE-GC/MS provided a quantitative measure (>80%) of the pesticides in non-fat baby food (fruits and vegetabl es). Direct ELISA applied to diluted non-fat food also gave a quantitative measure of the target pesticides. The ESE-ELISA method provided a quantitat ive determination of atrazine in both non-fat and fatty baby food. (C) 1999 Elsevier Science B.V. All rights reserved.