title: Sterols as biomarkers in the surface microlayer of the estuarine areas.
abstract: This study aims to determine the concentration of sterols used as biomarkers in the surface microlayer (SML) in estuarine areas of the Selangor River, Malaysia. Samples were collected during different seasons through the use of a rotation drum. The analysis of sterols was performed using gas chromatography equipped with a flame ionisation detector (GC-FID). The results showed that the concentrations of total sterols in the SML ranged from 107.06 to 505.55 ng L(-1). The total sterol concentration was found to be higher in the wet season. Cholesterol was found to be the most abundant sterols component in the SML. The diagnostic ratios of sterols show the influence of natural sources and waste on the contribution of sterols in the SML. Further analysis, using principal component analysis (PCA), showed distinct inputs of sterols derived from human activity (40.58%), terrigenous and plant inputs (22.59%) as well as phytoplankton and marine inputs (17.35%).
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Department of Marine Chemistry and Pollution, Faculty of Marine Science and Environment, Hodeidah University, Yemen.
authors: Murad Ali
authors: MA
authors: Alsalahi
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Centre for Tropical Climate Change System (IKLIM), Institute for Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. Electronic address: talib@ukm.my.
authors: Mohd Talib
authors: MT
authors: Latif
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Masni Mohd
authors: MM
authors: Ali
authors: Centre for Tropical Climate Change System (IKLIM), Institute for Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Doreena
authors: D
authors: Dominick
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Centre for Tropical Climate Change System (IKLIM), Institute for Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Md Firoz
authors: MF
authors: Khan
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Nur Ili Hamizah
authors: NI
authors: Mustaffa
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Centre for Tropical Climate Change System (IKLIM), Institute for Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Mohd Shahrul Mohd
authors: MS
authors: Nadzir
authors: School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Department of Marine Chemistry and Pollution, Faculty of Marine Science and Environment, Hodeidah University, Yemen.
authors: Essam
authors: E
authors: Nasher
authors: Environmental Forensics Research Centre (ENFORCE), Faculty of Environmental Studies, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
authors: Mohamad Pauzi
authors: MP
authors: Zakaria
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002849:Chromatography, Gas; D004784:Environmental Monitoring / Q000379:methods*; D063366:Estuaries; D006801:Humans; D008296:Malaysia; D045483:Rivers / Q000737:chemistry*; D012621:Seasons; D013261:Sterols / Q000032:analysis*
chemical_list: D015415:Biomarkers; D013261:Sterols
keywords: Diagnostic ratio; Organic compounds; Principal component analysis; Selangor River