Deternination of aliphatic and aromatic hydrocarbon concentration in he surficial sediments off the coast of Pulau Pinang

Abstract

The surficial sediment from 10 stations oof the coast of Pulau Pinang were collected, and analysed for the concentration of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) by using Gas Chromatography-Mass Spectrometer (GC-MS) right after the extraction and separation processed. Sediment were extract using ultrasonication method followed by fractionation using silica-alumina column. 27 targeted aliphatic hydrocarbon ranging from n-Dodecane (C12) to n­ Hexatiracontane (C36), and 19 targeted species identified and quantified by matching their retention time with a aliphatic and PAH standards respectively. Total aliphatic hydrocarbons (TAH) and PAHs (IPAH) found in this study ranged 233.91-1698.26 ng/g and 1.87-787.85 ng/g respectively. The concentration of TAH and IPAH were affected by the characteristic of area near to the stations. IP AH and other ratios such as low molecular weight/high molecular weight (LMW/HMW); Benz[ a] anthracene/binz[ a] anthracene+chrysene (BaAfI228); Phenanthrene/ Anthracene (Phe/ Ant); Anthracene/ ( Anthracene+ Phenanthrene) Ant/(Ant+Phe) in each station indicated that, the study areas were considered as low pollution area and were affected by the type of PAH sources. For TAH, Carbon Preference Index (CPI) 13-35, alkanes ratio for terrigenous over aquatic input (TAR), and ratio of low molecular weight /high molecular weight (LMW /HMW) indicated that the biogenic inputs were significantly higher than the anthropogenic inputs.