The Distribution Of N-alkane And PAH In Particulate Matter Within The Huanghe Estuary And Huanghe River

This paper based on the task of 973"Study on carbon flux of the typical river in China". According to the approach which can be useful in studying the source of organic matter. We studied n-alkanes and Polycyclic aromatic hydrocarbons (PAH) for biomakers and discussed the source of organic matter and temporal-spatial distribution in the different streams and estuary of Huanghe River. We also analysis n-alkanes and PAH in the size-fractions of total suspended soild (TSS). The conclusion is as follow:We analyse n-alkanes and PAH by gas chromatography(GC), the approach which can be useful in studying n-alkanes and PAH. The recovery of PAH and n-alkanes in TSS extraced by Accelerated Solvent Extraction (ASE) ranged from 79.0% to 140.2% and 72.6% to 138.0%, the recovery of PAH and n-alkanes in sediment extraced by Soxhlet apparatus ranged from 68.4% to 128.0% and 61.0% to 112.0%.Results show that a unimodal distribution of particulate n-alkanes in the upper stream, and bimodal distribution in the middle stream and downriver. Distinct seasonal variations are found in Huayuankou samples also. The levels of n-alkanes in TSS from aquatic biological origin are compared among four seasons: the highest values is occurrence in the autumn, the higher is in the summer and spring, and the lowest in the winter. Particulate n-alkanes show a bimodal distribution in the spring, summer and autumn, but unimodal distribution in the winter in the middle stream of river. The concentration and distribution pattern represent a invariant characteristics between in flood period and in level period, but the levels of alkanes are significantly higher in August owing to water and sediment regulation, at least by one order of magnitude, than levels measured in other months.The concentrations of the odd number (except nC21, nC33 ) n-alkanes, nC16, nC18, nC24, nC28, nC30 decrease with increasing the size of particle in TSS, and the levels of these compound in the fine particle are much higher than in the large size particle. But the concentrations of nC20, nC21 are relative low, which increase with increasing the size of particle. The levels of nC14, nC22, nC26, nC32 and nC33 show no variation to be dependent on the size of particle. But The levels of nC14, nC22 and nC26 in the fine particle are higher than in the large size particle. PAHs in TSS of Huanghe estuary and off the estuary are mostly pyrogenic origin. The levels of four-rings PAH, benzo[b]fluoranthene and benzo[k]fluoranthene decrease with increasing the size...