Objective To explore the relationship between the concentration of t, t-2, 4-DDE in cooking oil fume(COF) and the cooking temperature. Methods The temperature control system of oil heating was developed, the activated carbon was used to collect gaseous pollutants. Six samples were prepared at 60, 90, 120, 150, 180, 210, 240 and 270 ℃. The concentration of t, t-2, 4-DDE in COF was analyzed by GC-FID. Results The concentration of t, t-2, 4-DDE in COF was below the detection limit when the oil temperature was not higher than 120 ℃. Among the 150 ℃ and 270 ℃ groups, the concentration of t, t-2, 4-DDE showed a significant increase. Conclusion The concentration of t, t-2, 4-DDE in COF may obviously increase as the cooking temperature is not lower than 150℃.

Objective To establish a method of GS-MS for determination of polychlorinated biphenyls (PCBs) in human cerumen. Methods The PCBs in cerumen samples was separated by n-hexane extraction, liquid-liquid extraction separation and column chromatography purification, then was analyzed quantitatively by gas chromatography and affirmed qualitatively by mass spectroscopy. Results The detection limit, average recovery rate and precision of this method were 0.15 ?g/g fat, 92.1% and 3.0%-4.6% (n=12) respectively. The contents of PCBs in 90 cerumen samples collected in polluted and control areas were detected. The levels(0.00-18.42 ?g/g fat) of PCBs in cerumen collected in polluted area were significantly higher than that in the control area(P