Determination of Specific Iron Chelator by Using LC-ICP-MS and LC-ESI-MS

Identification and quantification of siderophore type chelate was undertaken using recently developed high-performance liquid chromatography-mass spectrometry methods. Five different siderophore type chelates were detected and the compounds comprised of two groups; ferrioxamines. In the dissolved phase, three types of hydroxamate siderophore have been identified; Ferioxamine B (FOB), Ferrioxamine G (FOG) and ferrioxamine E (FOE). Concentration of dissolved FOB, FOG and FOE are extremely low between 0–135 x 10-18 M, and their distribution is spatially and temporally variable in this region. The concentration and diversity of siderophore type chelates determined during this study, was lower than those reported previously for dissolved ferrioxamine siderophore concentrations at lower latitudes in the Atlantic Ocean. The initial data from this study suggested that dissolved siderophores in this region is not an important fraction (< 0.1%) of the natural organic Fe(III) binding ligand pool

Identification and quantification of marine siderophores using high-performance liquid chromatography with electrospray ionization mass spectrometry

Siderophores are low-molecular-weight organic compounds (500 - 1500 Da) produced by heterotrophic bacteria and highly selective for Fe(III). These complexation of iron by siderophores has the potential to affect both the solubility and bioavailability of iron (III) in seawater. We have determined the ferrioxamine siderophores in the seawater samples from high latitude North Atlantic Ocean The identification and quantification of this siderophore type chelate was done by using recently developed high-performance liquid chromatography-mass spectrometry methods. Five different siderophore type chelates were detected and the compounds comprised of two groups; ferrioxamines and amphibactins group. In the dissolved phase, three types of hydroxamate siderophore have been identified; Ferioxamine B (FOB), Ferrioxamine G (FOG) and ferrioxamine E (FOE). Concentration of dissolved FOB, FOG and FOE are extremely low between 0–135 x 10-18 M. Our present data indicated the presence of low concentrations of dissolved siderophores in the high latitude of the Atlantic Ocean and suggest that siderophore distributions are both spatially and temporally variable

How to perform solah with upper limb injuries

Solah is one of the Five Pillars of Islam. The task of performing solah is of utmost importance for all Muslims. The order of performing solah was bestowed directly to Prophet Muhammad S.A.W during Israk Mikraj. This highlights the greatest priority of performing solah even in injurious conditions. In patients with upper limb injuries and limited function, solah is compulsory and must be performed with any remaining physical functions. A group of undergraduate medical students researched and discussed the correct method of performing ablution and solah in injured patients with a facilitator from Kulliyyah of Islamic Revealed Knowledge, IIUM. The issues discussed were the options available in performing ablution prior to solah which either was with water, tayammum (dust), or both. The method of performing solah in upper limb injuries was highlighted. We conclude that the tayammum is the most practical and feasible ablutions method for patients with upper limb injuries prior to perform solah

Sikap dan motivasi murid Bajau dalam mempelajari bahasa Melayu sebagai bahasa kedua

Kajian ini dijalankan untuk mengenal pasti sikap dan motivasi yang dimiliki oleh murid-murid Bajau sekolah rendah pedalaman yang mempelajari Bahasa Melayu sebagai bahasa kedua. Kajian ini bertujuan untuk mengenal pasti sama ada terdapat perbezaan sikap dan motivasi antara murid Bajau berdasarkan jantina dalam mempelajari bahasa Melayu. Seramai 56 orang murid Bajau tahun 4, 5, dan 6 dari 3 buah sekolah rendah pedalaman di daerah Beluran dipilih sebagai responden menggunakan kaedah pensampelan bertujuan. Instrumen kajian yang digunakan untuk mengutip data adalah soal selidik yang mengandungi 36 item dan terbahagi kepada dua konstruk iaitu sikap dan motivasi. Dapatan kajian menunjukkan murid-murid Bajau sekolah rendah mempunyai sikap yang positif dan motivasi yang tinggi dalam mempelajari bahasa Melayu sebagai bahasa kedua. Hasil dapatan kajian juga menunjukkan terdapat perbezaan sikap dan motivasi antara murid lelaki dengan murid perempuan yang mempelajari bahasa Melayu. Kesimpulannya, murid-murid Bajau menunjukkan sikap yang positif serta motivasi yang tinggi dalam mempelajari bahasa Melayu sebagai bahasa kedua

Determination of natural organic Fe (III) binding ligand at Pulau Perhentian

The organic ligands concentrations [FeL] ranged between 432.8-900.6 nM and showed conditional stability constants (log K') between 22.68 and 24.63 in the surface waters of the Pulau Perhentian. Dissolved Fe was therefore largely complexed by organic ligands (100%). The organic ligand concentrations ([FeL]) were always in excess of [dFe] throughout the water column. The ligands are thought to play an important role in keeping Fe in solution and hence regulating Fe availability to organisms. The ratio of [FeL]/[dFe] was used to analyse trends in Fe speciation observed during this study. An enhanced and variable FeL]/[dFe] ratio (1.0-1.2) was determined throughout the water column. These observations indicate the importance of phytoplankton in maintaining the ratio by Fe uptake and ligand production. This observation indicates that the Fe binding ligand sites become occupied and even almost saturated at the study area

Study of dissolved copper (II) speciation at coastal water of Peninsular Malaysia

Samples from Perhentian and Pangkor Island Marine Park, Peninsular Malaysia were analyzed for Cu(II) speciation by using CLE-AdCSV. Northeast monsoon effect was studied in Perhentian and compared with Pangkor. Excess concentration of CuL found for all stations in both islands showed >99.5% of total dissolved Cu (dCu) was bound to Cu (II) complexing ligands. The log K’CuL>12 data indicated the presence of strong natural ligands (L1) in Perhentian Island. Lower log K’ (log K’=10 to 12) and two types of ligands (L1 and L2) were found in Pangkor Island. The ratio of CuL/dCu was analysed to see the ligand distributions, and saturation rate with dissolved Cu. Statistical analysis showed weak relationship between the in-situ parameters to log K’ values (p>0.05). The log K’CuL (PP: 12.00-12.96, PG: 10.93-12.840) data suggested that the dissolved Cu are used by marine organisms, thus preventing the free Cu2+ ions to be produced

Optimization of extraction methods and detectors for heavy metal analysis in sediment

The optimization analysis, extractions of metals (Zinc, Cadmium, Lead, and Copper) content in Certified Reference Material, BCR ®-667 of estuarine sediment was carried out by different procedures of acid digestion such hydrochloric acid-nitric acid-hydrofluoric acid, nitric acid-perchloric acid, and sulphuric acid-hydrogen peroxide mixtures. These metals concentrations were determined by using Differential Pulse Stripping Voltammetry (DPSV) and Inductive Coupled Plasma-Mass Spectrometry (ICP-MS). The purpose was to determine these metals (Zn, Cd, Pb, Cu) concentration in sediment samples simultaneously in good precision and accuracy measurement. The results showed both have small standard deviation indicates good precision of metals determinations in both detectors. The accuracy for DPSV ranged from 18.85-154.38% and ICP-MS ranged from 75.28-90.13%. Zn, Cd, Pb, and Cu were simultaneously measured in BCR ®-667. When the optimized method was applied into real sediment samples, both determinations showed a good precision in analysis but ICP-MS was selected as the detector. It measured all the metals of interest (Zn, Cd, Pb, Cu) in the real sediment sample simultaneously

Removal of Fe ion from polluted water by reusing spent coffee grounds

High concentration of iron (Fe) levels (above 1.0 mg/L) in water causes bad taste, staining and deposition in pipes and results in high turbidity in water supplies. Existing treatment technologies (which have been conventionally applied to remove Fe ions), are expensive and cause toxic sludge production. A set of experiments was carried out to evaluate the Fe uptake potential of spent coffee grounds by conducting batch tests in an aqueous solution through a biosorption process. Batch sorption studies were conducted based on pH, contact time, adsorbent dosage and adsorbent particle size. In addition, initial metal concentration was investigated. Flame atomic adsorption spectroscopy analysis revealed that the maximum adsorption recorded was 0.470 mg g-1 by using 0.30 g of 210-355 µm coffee with the maximum uptake percentage of Fe (92.9%) for 60 minutes at pH 4. Adsorption behavior of Fe ions on a surface of coffee grounds was well-interpreted by Langmuir model (R2 = 0.999). A kinetic study indicated that the Fe ions uptake was well-fitted by the pseudo second-order reaction model with good correlation (R2 = 0.993). The study offered an affirmative answer to the hypothesis of reusing eco-friendly and low-cost coffee grounds for removal of Fe ions from polluted waters

Heavy metal exposure from co-processing of hazardous wastes for cement production and associated human risk assessment

This study was carried out to determine the concentration of heavy metals (Cd, Ni, Pb, Cr, Ni and Zn) in ordinary Portland cement (OPC) produced from the co-processing with hazardous waste in comparison with OPC produced using natural raw materials. The results showed that the concentration of heavy metals in cement produced from natural raw material was in the order of Zn > Pb > Cr > Ni > Cu > Cd. Zn and Cd were the highest and the lowest concentrations, respectively, in cements produced from the co-processing activity. The difference between heavy metals concentrations in OPC produced with and without co-processing was found to be statistically significant. The concentration of heavy metals in the cement produced is generally factory dependent. The human risk assessment associated with the heavy metals for non-carcinogenic and carcinogenic risks has been evaluated. The calculated hazard index (HI) and total lifetime cancer risks (LCR) were lower than the acceptable threshold reference values, HI dermal > inhalation