胶州湾滩涂养殖区沉积物脂肪烃的特征参数

Characteristic parameters of aliphatic hydrocarbon of sediments on tidal flat culture zone in Jiaozhou Bay

本文研究了胶州湾滩涂养殖区沉积物中脂肪烃组成特征、特征参数及其来源解析.采集了9个站位的养殖区表层沉积物样品,经正己烷/二氯甲烷(体积比,1∶1)混合溶剂超声提取,旋转蒸发、净化浓缩后进行GC-MS检测分析.结果表明,各站位沉积物正构烷烃峰型十分相似,呈双峰态分布,显示了陆源与海源双重贡献特征.前峰型为主、陆/水生类脂物比值TAR均值为0.60、C31/C19均值为0.63,同时表明海相来源贡献大于陆相来源.奇偶优势指数OEP、Pr/Ph比值较低,均值分别为1.67、0.70,与C30βα莫烷/C30αβ藿烷、Ts/Tm、C29甾烷αββ/(αββ+ααα)一致,表明研究区沉积物有机质成熟度较高.结合碳优势指数CPI、短链/长链比L/H、∑n-Alk/C16、C29甾烷20S/(20S+20R)、C31藿烷22S/(22S+22R)、C32藿烷22S/(22S+22R)多个特征参数综合分析,证实了滩涂养殖区内存在石油及其衍生品的污染.较高的Ts/Tm值反映了研究区为强还原沉积环境,与Pr/Ph指示的沉积环境一致.

The composition and characteristic parameters of 9 surface sediment samples collected from Jiaozhou Bay were investigated. The samples were extracted with a mixture of 1∶1 （ V/V ） dichloromethane-haxane and analyzed by GC-MS after purification and concentration. n-Alkanes distribution patterns in all stations were characterized by double peak-cluster, which indicates dual sources from terrestrial and marine origins. The more abundant peak is the former one, while the average value of TAR and C31/C19 ratio are 0. 60, 0. 63, respectively, which show that marine contribution is higher than terrestrial source. The ratio of Pristane/Phytane （ Pr/Ph） and Odd-Even Predominance （OEP） are low and their average value are 1.67, 0.70. Combined with C30βα/C30αβ, Ts/Tm、C29αββ/（αββ＋ααα） , all these indices consistently suggest that the maturity of organic matters in sediments is high. Comprehensive analysis with other characteristic parameters, such as Carbon Preference Index （CPI）,L/H,∑n-Alk/C16,C29ααS/（S＋R）,C31αβS/（S＋R）,C32αβS/（ S＋R） indicates that beach culture area is contaminated by Petroleum or its derivatives. Higher Ts/Tm value reflects the study area is a strongly reducing sedimentary environment, which is consistent with the indicated rsults by Pr/Ph.