Marinah Mohd Ariffin

A green solvent holder in electro-mediated microextraction for the extraction of phenols in water

Electro-mediated microextraction (EMM) combined with micro-high performance liquid chromatography-ultraviolet detection was successfully developed for the determination of selected phenols, namely 4-chlorophenol (4CP), 2-nitrophenol (2NP) and 2,4-dichlorophenols (2,4 DCP) in water. A solvent-impregnated agarose gel disc was utilized as a solvent holder in this study. Under optimum extraction conditions, the method showed good linearity in the range of 0.1-250µgL-1, 0.3-250µgL-1 and 0.2-500µgL-1 for 4CP, 2NP and 2,4 DCP, respectively with correlation coefficients of ≥ 0.9975, ultra-trace LODs (0.03-0.1µgL-1) and satisfactory relative recovery average (85.0-114.1%) for the analysis of selected phenols. The proposed method was rapid and eco-friendly as the solvent holder was constructed using minute amounts of extraction solvent immobilized within the biodegradable agarose gel disc. A comparative microextraction technique termed solvent-impregnated agarose gel liquid phase microextraction (AG-LPME) was re-optimized and validated for the extraction of phenols in water. The method offered good linearity, ultra-trace LODs ranging 0.1-0.5µgL-1 and satisfactory average of relative recovery (86.1-114.1%). The EMM was superior in terms of sensitivity and time-effectiveness compared to AG-LPME. Both techniques combine extraction and pre-concentration in mini-scaled approaches using an eco-friendly solvent holder that fulfil the green chemistry concept.

A Baseline Assesment on the Distributions and Sources of Aliphatic and Polycyclic Aromatic Hydrocarbons in Abiotic Environment of Terengganu National Park

A baseline study to assess the distributions of aliphatic and polycyclic aromatic hydrocarbons in abiotic environment consisting of soil, sediment and atmospheric particulate samples was carried in Terengganu National Park. Aliphatic hydrocarbons were found in all three media studied whilst polycyclic aromatic hydrocarbon (PAH) compounds were detected, only in the atmospheric particulate samples, at trace levels. The 24 hr-PM10 and Total Suspended Particulate (TSP) concentrations is still below the recommended Malaysian Air Quality Guidelines for the respective parameter. Analyses of the results suggest that terrestrial plant waxes is the main source of aliphatic hydrocarbons in the study area whereas sources for PAHs in the particulate samples are most likely derived from combustion sources. The detection of PAHs in the aerosol samples also suggest possible anthropogenic input of particulate matter to the study area; however the levels are still well below the values reported for other locations in Malaysia.

Characterization Study of a Highly Specific Affinity Membrane for Trypsin Purification

This study aimed to characterize a highly specific affinity membrane for trypsin separation. The basic membrane was fabricated using 15% polysulfone via phase inversion technique. Membrane surface modification was employed by immersing the native membrane into the chitosan solution for 60 minutes dip times. Further modification was performed to activate the PSf/chitosan hybrid membrane using glutaraldehyde before ligand immobilization. The prepared affinity membrane was characterized in term of morphology using scanning electron microscope and the presence of aldehyde group and ovomucoid were confirmed by ATR-FTIR. Performance of affinity membrane was valuted by adsorption study of trypsin enzyme. The observed results show that the developed affinity membrane, with 0.7 mg/ml ligands was able to adsorb trypsin for about 0.219 mg/cm2 membrane