珠江澳门河口沉积物柱样品正构烷烃研究

报道了珠江澳门河口沉积物柱芯榈中正构烷烃的浓度和分布类型，并通过因子分析方法对正构烷烃的来源加以初步探讨。沉积物柱芯样品于１９９７年３月采自珠江澳门河口区，沉积年龄以＾２１０Ｐｂ法稳恒初始放射性模式（ＣＡ模式）测定。样品中的有机污染物以二氯甲烷／丙酮混合溶剂索氏提取后，正构烷烃组分以ＧＣ／ＭＳＤ定量分析测定。研究结果表明，该现代沉积物桩芯样品沉积时间约历时４０ａ，桩芯样品中正构烷烃的含量范围为０．

The study of n-alkanes in a sedimentary core from Macao Estuary, Pearl River

Concentrations and different distribution patterns of n-alkanes in a sediment core are represented. Factor analysis statistical method was used to discuss the contaminated sources of alkanes. The core sample collected in Macao Estuary. Pearl River at March 1997 was dated by ~(210)Pb techniques in a CA Model. Organic pollutants were extracted from sediments using soxhlet procedure with Solvents of dichloromethane and actone. Concentrations of n-alkanes in the sediment core were analyzed by chromatography / mass spectrometry used an internal standard material to quantify the concentrations of n-alkanes. The result of this study shows that the sedimentary core represented about 40 years of depositional times, which represents a high-resolution deposition record of the environment for the studied areas. The concentration for the total n-alkanes ranges from 0. 47 ~ 27. 5 mg/kg (dry weight) and 42 - 2 528 mg/kg as TOC in dry weight for the core. Two samples with sedimentary time of 1988 - 1990 and with very high concentration of n-alkanes were contaminated by oil, because the distribution pattern and compositional index of these sediments indicated that the alkanes mainly came from crude oils. Factor analysis reveals that there may be 4 types contaminated sources, among that the contribution of land-runoff is the largest one, accounting for proportion to the total 52. 5%, and the four types of contaminant sources correspond to four different composition characteristics of n-alkanes in sedimentary cores. Several composition indexes of the alkanes in the sediment core were also computed to discuss the possible contamination sources.