汕头湿地示范区红树林底栖动物体中石油烃组成特征分析

ANALYSIS OF CHARACTERISTICS OF PETROLEUM HYDROCARBONS IN ZOOBENTHOS FROM SHANTOU MANGROVES

采集了汕头湿地示范区三种红树林常见底栖动物蟹类和螺类,采用有机溶剂超声提取,氧化铝硅胶层析柱净化,气相色谱仪分析的方法,分析了蟹和螺样品石油烃的组成、来源和降解.结果显示,蟹和螺样品都具有很宽的正构烷烃范围,分别是nC13—nC40和nC13—nC36;未分离复杂化合物(UCM)含量范围蟹是10.49μg.g-1—27.40μg.g-1,螺是17.16μg.g-1—41.37μg.g-1;碳优势指数(CPI)值范围蟹为2.70—7.93,螺为1.84—5.56;nC17/Pr比值范围蟹是0.81—2.74,螺是1.57—2.48;nC18/Ph比值范围蟹为0.60—3.65,螺为0.92—1.30.表明螺类体内石油烃兼具有石油源与生源烃的特征,蟹类则具明显高等植物蜡源特征;蟹类和螺类体内都累积了UCM,且螺类累积量高于蟹类累积量;蟹类和螺类体内的正构烷烃都已产生了降解和代谢,且蟹类降解和代谢正构烷烃的速率明显高于螺类.

In order to find out the current status and characteristics of composition and accumulation of petroleum hydrocarbons in zoobenthos inhabited in mangroves, samples of crab and conch were collected from three mangroves in Shantou wetland demonstration site. The samples were extracted by organic solution in ultrasonic, purified by aluminum and silica gel chromatography column and detected by gas chromatography （GC） . The component, source and degradation of petroleum hydrocarbons in samples were analyzed. Results showed that n-alkane distribution in all samples covered a wide range from nC13 to nC40 UCM concentrations ranged from 10. 49 μg .g^-1to 27.40 μg.g^-1 in crabs, and from 17. 16 ~μ .g^-1to 41.37 μg.g^-1 in conchs. CPI minimum in crabs was 2.70, maximum was 7.93, while in conchs they were 1.84 and 5.56, respectively. The ratios of nC17/Pr were from 0. 81 to 2. 74 in crabs, and from 1.57 to 2.48 in conchs. The ratios of nC18/Ph in crabs and conchs were from 0.60 to 3.65, and from 0. 92 to 1.30, respectively. These indicated that the source of petroleum hydrocarbons in conchs was both petrogenic and biogenic, while ＇in crabs they might be from higher plant wax input; UCM has been accumulated, its concentration in conchs was higher than in crabs; n-alkanes have been degraded and metabolized, and the rates of degradation and metabolism was significantly faster in crabs than in conchs.