Mohd Lias Kamal

Marine Environmental Risk Assessment of Sungai Kilim, Langkawi, Malaysia: Heavy Metal Enrichment Factors in Sediments as Assessment Indexes

Concentrations of Cd, Co, Pb, and Zn in riverbed sediments from six sampling stations along the Sungai Kilim, Langkawi, Malaysia, were determined by using the Teflon Bomb Digestion. From this study, the concentrations of heavy metals in riverbed sediments were found ranging between 6.10 and 8.87 μg/g dry weight for Co, 0.03 and 0.45 μg/g dry weight for Cd, 59.8 and 74.9 μg/g dry weight for Zn, and 1.06 and 11.69 μg/g dry weight for Pb. From the observation, these areas were polluted by domestic waste, aquaculture, and tourism activities. For clarity, enrichment factor index was used to determine the level of sediment contamination in the study area. From this study, the average EF value is a bit high for Cd () followed by Zn (), Pb (), and lastly, Co (). Based on the contamination categories, Cd was categorised as moderately enriched, while the rest of the metals studied were in deficient-to-minimally enriched by the anthropogenic sources.

Distribution of Heavy Metals, Organic Matter and Mean Size in Sediment at the Perlis River

The distributions of heavy metals (As, Cd, Cr, Cu, Pb and Zn), organic matter and mean size were determined in the riverbed sediment by means of 10 sampling points in Perlis River. From this study, mean of heavy metals concentration in the sediment was dominated primarily by Cr with the concentration of 97.02 ± 9.34 mg/kg dry weight, followed by Zn (80.84 ± 31.68 mg/kg dry weight), Pb (58.67 ± 32.63 mg/kg dry weight), Cu (26.69 ± 10.34 mg/kg dry weight), As (24.52 ± 8.77 mg/kg dry weight) and Cd (0.11 ± 0.03 mg/kg dry weight). The distribution of organic matter ranged between 3.90 and 7.56 %, while mean size ranged between 6.95 and 7.55 respectively. The average of each heavy metal except Cd and Zn were found to be above the ISGQ standard which was proposed by Canadian Sediment Quality Guidelines. Correlation analysis showed that all metals except Cu were significantly correlated with the distribution of organic matter. This finding is crucial to determine the metals level in the sediment as well as to update the current status of metals pollution in the Perlis River.

Identification of Alkaloid compounds and Antioxidant Activity of Rafflesia Cantleyi and Its Host, Tetrastigma Tuberculatum

Alkaloid compounds in Rafflesia cantleyi and host, Tetrastigma tuberculatum were identified using the phytochemical screening method and HPLC technique. The results showed positive test for the host, T. tuberculatum which indicates the presence of alkaloid whereas the screening test for R. cantleyi showed that alkaloid is absenced. Both extract were then subjected to HPLC for alkaloid identification and caffeine was used as standard. The spectroscopic data from HPLC revealed the presence of caffeine in both methanol extracts. The methanol extract of both samples were also tested for antioxidant activity by using DPPH free radical scavenging activity. Result showed that the radical scavenging activity of R. cantleyi and T. tuberculatum are comparable to the standard reference, BHT but higher than the standard alpha tocopherol.