中文摘要：

采用GC/MS 分析方法测定了珠江三角洲4个沉积柱（分别采自东江东莞段、珠江广州段、北江中段和西江入海口）中短链（ SCCPs）和中链氯化石蜡（ MCCPs）的含量，分析了CPs垂向变化规律及沉积过程中的脱氯降解行为．4个沉积柱中SCCPs浓度范围为224-3800 ng·g-1，MCCPs浓度范围为692-12000 ng·g-1．CPs在沉积柱中的垂向分布结果表明，珠江三角洲地区近年来CPs的使用量持续上升，且MCCPs所占比例呈递增趋势．沉积柱中CPs的氯含量均出现随深度增加氯含量降低的现象，显示CPs在沉积埋藏过程中可能存在脱氯的降解过程，短链（ C10-11）高氯代（ Cl9-10）的同类物具有较高的脱氯降解能力．

英文摘要：

Short-chain and medium-chain chlorinated paraffins （ SCCPs and MCCPs ） in four sediment cores collected in the Pearl River Delta were determined using GC/MS to comprehensively investigate the temporal distributions of CPs. The concentrations of SCCPs and MCCPs in sediment varied from 224 to 3800 ng·g-1 , and from 692 to 12000 ng·g-1 , respectively. The vertical profile of CPs in the sediment core indicated a rapid increase in the usage of CPs and a shift to more MCCPs in recent years. The decreased chlorine content of CPs with increasing sediment depth indicated that the dechlorination occurred after deposition of CPs in sediment. The dechlorination potential of higher chlorinated and lower carbon chain congeners was higher than those of long carbon chain and lower chlorinated congeners.