PURGE-AND-TRAP EXTRACTION WITH GC-MS DETERMINATION OF VOLATILE ORGANIC-COMPOUNDS IN TABLE-READY FOODS

A purge and trap procedure has been developed for the determination of volatile organic compounds (VOCs) in table-ready foods. VOC analytes are collected on a Vocarb 3000 trap, thermally desorbed, and cryofocused directly on a capillary DB-624 column with GC-MS quantification. Adequate precision was achieved for 45 of the 60 analytes of U.S. EPA Method 524.2. Recoveries from 9 food samples fortified with these 45 analytes at 100 ppb and analyzed in duplicate ranged from 75.1 to 117% and from 61.3 to 160% for those fortified at 10 ppb. Average percentage of recovery standard deviation (%RSD) values were 11.3 and 20.4, respectively. Additionally, 234 table-ready foods of the FDA Total Diet Program were analyzed. A total of 77 foods showed residues >50 ppb, 43 > 100 ppb. Only 47 items contained no residues. Toluene was the most common residue encountered, with residues in 91 foods. Cake doughnuts contained the highest total VOC residues (802 ppb).