土壤-水悬浊液体系全量置入红外光度法测定土壤中的总石油烃

Soil-Water Turbid Liquid System for Determination of Total Petroleum Hydrocarbons in Soils by One-Time Extraction Infrared Spectrophotometry

从考虑土壤本身复杂性而引起的基体效应出发,建立了土壤-水悬浊液体系以探求更合理可靠的土壤总石油烃测定的前处理过程。研究了土壤-水悬浊液体系中以CCl4为萃取剂全量置入提取土壤中总石油烃(TPH)红外光度法(IR)测定的可行性及其影响因素,阐明了应用该体系提取总石油烃的优化条件为:当水土比例(V/m)为12.5∶1、振荡强度为150 r/min、振荡时间为4 h、实验温度为55℃时,对土壤中的总石油烃可获得最佳提取效率。在优化条件下,土样的柴油(D ROs)和标准矿物油(MOOs)加标回收率均值分别为100%和96%,其相对标准偏差RSD分别为4.8%和4.6%。基于该体系在99%置信水平上的方法检出限(MDL)为2.5 mg/kg,定量检测限(RQL)为10.0 mg/kg。

According to the matrix effect of the soil resulted from its complex properties, a soil-water turbid liquid system was developed to search for a more reasonable and reliable pretreatment process of determining total petroleum hydrocarbons in soils. This paper studies the feasibility of soil-water turbid liquid system with tetrachloromethane for extracting agent to determine total petroleum hydrocarbons （TPH） in soils by infrared spectrophotometry（IR） and the factors that affect the system. Optimum conditions for the best extraction efficiency were found to be based on the suitable water/soil proportion（12.5 ： 1-15： 1）, oscillation intensity （150 r/min）, oscillation time （4 hours） and extracting temperature （55℃）. Quantitative recoveries for diesel range organics （DROs） and mineral oil organics （MOOs） were obtained using the optimized conditions. The DROs recovery averaged 100% and the MOOs recovery averaged 92% with 4.8% and 4.6% RSD（relative standard deviation） respectively. The method detection limit （MDL） was 2.5 mg/kg and the reliable quality limit （RQL） was 10. 0 mg/kg based on the system on the level of confidence in 99%.