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Food-grade PVC film containing 28.3% dioctyladipate (DOA) plasticizer was used to wrap chicken meat samples, with and without skin, contained in a polystyrene tray. Samples were then irradiated with gamma-radiation [60Co] at doses equal to 4 kGy and 9 kGy corresponding to "cold pasteurization". Irraddiation was carried out at 8-10 degrees C and samples were subsequently stored at 4-5 degrees C. Contaminated chicken meat samples were analysed for DOA at intervals between 7 h and 240 h of contact, using an indirect GC method. Identical non-irradiated (control) samples were also analysed for their DOA content. Results showed no statistically significant differences in migrated amounts of DOA between irradiated and non-irradiated samples. Neither were differences observed between samples irradiated at 4 kGy and 9 kGy. This was supported by identical IR spectra recorded for irradiated and non-irradiated samples and leads to the conclusion that, at such intermediate radiation doses ( < or = kGy), the migration characteristics of PVC film are not affected. DOA migration was found to be time dependent, approaching equilibrium after approximately 170 h for the chicken flesh plus skin samples and 120 h for the chicken flesh samples. The amount of DOA migrated into chicken flesh plus skin samples was significantly greater (3.2-22.3 mg/dm2) than that for chicken flesh samples (0.9-8.9 mg/dm2). After 240 h of sample/film contact under refrigeration, loss of DOA was approximately 35.6% for chicken flesh plus skin samples and 14.3% for chicken flesh samples. Sample spoilage, as demonstrated by off-odour development, occurred after approximately 120 h of refrigerated storage. Diffusion coefficients for DOA were calculated and were found to be lower for chicken flesh (1 x 10(-13) than for flesh plus skin (4.4 x 10(-13)) samples.

A method for the measurement of dicarboxylic acids in amniotic fluid was developed that utilizes isolation of the acids by liquid partition chromatography and quantification by ammonia chemical ionization selected ion monitoring, gas chromatography-mass spectrometry. The concentrations of dicarboxylic acids in ten normal samples of amniotic fluid (mumol/l +/- 1 S.D.) were glutaric acid 0.91 +/- 0.15, adipic acid 0.33 +/- 0.08, suberic acid 0.27 +/- 0.08, and sebacic acid 0.21 +/- 0.10. A highly elevated concentration of 14.48 mumol/l glutaric acid was found in the amniotic fluid of a pregnancy in which the fetus was affected with glutaric aciduria type II. Adipic, suberic and sebacic acids were also significantly elevated. The dicarboxylic acids were normal in the amniotic fluid of a pregnancy at risk for glutaric aciduria type II in which the fetus was unaffected. This method is suitable for the rapid prenatal diagnosis of glutaric aciduria types I and II and of potential value for the prenatal diagnosis of other inherited disorders in which dicarboxylic acids accumulate.