Effect of long term freezing on extraction of fat and 2378-TCDD from milk
Cow`s milk was spiked at 100 ppt with 14-C 2378-TCDD, homogenized, sub-divided into l00 ml aliquots and frozen at -21 C. After time intervals of zero days to one year the milk was thawed at room temperature during two to four hours with occasional shaking. The lipid fraction containing 14-C TCDD was extracted by means of liquid-liquid partitioning at basic pH (sodium oxalate, methanol, diethylether and hexane) and the emission from 14-C was determined. No effects of freezing period were observed on the extractability of fat nor 14-C TCDD. Neither was the variability of sub-dividing thawed milk affected. However, increasing the thawing time to more than 24 hours allowed bacterial transformation of the milk which became very heterogeneous. This drastically reduced extractability of fat and 14-C TCDD. The ratio of extractable 14-C TCDD to extractable fat remained constant in all samples independent of the fat recovery.
Bibliographic Reference: Paper presented: 8th International Symposium on Chlorinated Dioxins and Related Compounds, Umea (SE), Aug 21-26 1988
Availability: Available from (1) as Paper EN 34092 ORA
Record Number: 198910202 / Last updated on: 1994-12-01
Original language: en
Available languages: en