OBJECTIVETo investigate the feasibility of using the concentration of 1,2-DCE in blood as a biological monitoring indicators and build the determination method of 1,2-DCE in blood.

METHODSDose-response relationship of the exposure of 1,2-DCE and the level of 1,2-DCE in rat blood were investigated using the Pearson's correlation analysis. The concentration of 1,2-DCE in blood was determined using Headspace Sampler-Gas Chromatography-Mass Spectrometer (HS-GC-MS). 3.0 ml blood sample diluting with 2.0 ml 1,2-DCE standard serial solution was placed in 15 headspace bottles respectively and heated at 80 ℃ for 20 min.The vapor upon the headspace bottle was separated by capillary column and the concentration of 1,2-DCE was determined by massspectrum in SIM mode to draw a standard work curve. The within-run precision and the between-run precision were calculated by the relative standard deviation (RSD) of the concentration of 1,2-DCE in blood which was determined 6 times in a day and 6 times within 3 days respectively. The recovery rate was calculated by P=(C2 -C0)/C1 × 100%.

RESULTSWhen the treatment groups were exposed at dosage of 1,472, 2,550, 3,093, 3,976, and 4 418 mg/m(3), the average concentration of 1,2-DCE in rat blood was 24.1,231.6,344.3,395.1,538.5 μg/L. There was a positive correlation between the concentration of 1,2-DCE in rat blood and the exposed level of 1,2-DCE.The equation of dose-response relationship was y=0.162x -195.8,r=0.982 2,P=0.003 and the precision of exposure experiments was 7.04% -13.15%. 1,2-DCE contents within 0.259 -2 587 μg/L showed a good linear relationship and the regression equation was y=47 901x -357 446, r= 0.999 8. When the blood containing 0.259 μg/L 1,2-DCE was determined for six times, the average peak/peak signal-to-noise ratio was 56.55. The limit of detection (LOD) was 0.014 μg/L and the limit of quantification (LOQ) was 0.046 μg/L. The within-run precision was 1.23% -2.76% and the between-run precision was 2.21% -4.64%. The average recovery rate was 93.3% - 98.6%.

CONCLUSIONThe concentration of 1,2-DCE in blood could be used as a biological monitoring indicator. The method of the concentration of 1,2-DCE in blood determining by HS-GC-MS was characterized by high sensitivity, wide linear range, small interference, high precision and easy operation.