有机碳对土壤中有机氯污染物分布特征的影响

为了研究清洁地区土壤中w(OC)对有机氯污染物分布特征的影响，选择2006年春秋季采集于四川卧龙自然保护区高海拔地区的25个土壤样品，利用GC-HRMS方法测试有机氯污染物的残留量，利用回归分析方法研究有机氯污染物质量分数与w(OC)和海拔高度之间的关系. 结果表明:卧龙自然保护区有机氯污染物的质量分数均小于1 ng/g，与世界上其他边远地区的非农业土壤相似；土壤中w(OC)对有机氯污染物的分布特征有重要影响，分析的10种有机氯污染物质量分数〔以w(OC)校正〕与海拔高度均表现出较好的指数相关，且具有显著的统计学意义；有机氯污染物的质量分数〔以w(OC)校正〕随海拔高度上升而增加，表现出明显的“冷捕集”效应. 因此，在研究清洁地区土壤中有机氯污染物的分布特征时，以w(OC)进行校正是合理和重要的. 

Effect of Organic Carbon Contents on Organochlorine Pollutant Distribution Characteristics in Soil of Pristine Mountain Area

In order to study the effect of soil organic carbon contents on the distribution characteristics of organochlorine pollutants in pristine mountain area, 25 soil samples were collected at high altitude sites in both spring and autumn of 2006 in Wolong Nature Reserve. Typical organochlorine pollutants were measured by gas chromatography-high resolution mass spectrometry. Regression analysis was used to study the relationship between organochlorine pollutants and organic carbon contents as well as the altitude. The results showed that the concentrations of organochlorine pollutants were less than 1 ng/g in the Wolong Nature Reserve, which was similar to those of non-agricultural soils in other remote areas in the world. There is significant impact of the soil organic carbon contents on the distribution characteristics of organochlorine pollutants. The concentrations after organic carbon calibration for the ten organochlorine pollutants revealed a good exponential relationship to altitude, and positive coefficients showed significant statistical significance, exhibiting an obvious “cold-trapping” phenomenon. Therefore, it was reasonable and important to use organic carbon contents to calibrate the concentrations of organochlorine pollutants for this kind of study.