Characterization of Indonesian Bamboo Charcoal for Enhanced Adsorption Capabilities

Bamboo charcoal from four types of Indonesian bamboo species had been successfully prepared and characterized. The yield was 19.67%; 30.86%; 33,16% and 27,34 respectively for Apus bamboo, Javanese bamboo, Ori bamboo and Yellow bamboo. The activation of bamboo charcoal was carried out chemically using KOH and H3PO4. Activated bamboo charcoal was characterized for the content of water, volatile substance, total ash, and carbon, as well as iodine absorption capacity based on the technical standard of activated carbon SNI 06-3730-1995. The activated bamboo charcoal was also characterized using Fourier Transform Infrared (FTIR) to determine the functional groups, SEM to determine morphology and nitrogen adsorption desorption to determine the surface area. The activation process was able to reduce water, ash, volatile substance content; thereby increasing carbon content which has the potential to be used for adsorption, and this is evidenced by the increase in the value of iodine absorption. From the FTIR data activated bamboo charcoal shows the presence of a C=O at 1500-1600 cm-1, O-H at 3400-3500 cm-1 and CO at 1300-1400 cm-1 which has the potential to contribute the active site for adsorptionprocess. Based on SEM data the morphology of activated bamboo charcoal was porous. Enhance quantity of pores would increase the surface area and the adsorption ability. From the results of the surface area data, it was found that the 4 types of activated bamboo charcoal produced a higher surface area, and activation using KOH was more effective than H3PO4in increasing the surface area of activated bamboo charcoal

Microemulsion electrokinetic chromatography coupled with dispersive micro-solid phase extraction for determination of isoflavones in soybean products

A new method based on microemulsion electrokinetic chromatography (MEEKC) coupled with dispersive micro solid phase extraction (D-µ-SPE) was developed for the determination of isoflavones in soy products. D-µ-SPEs of real samples were carried out using multi-walled carbon nanotubes (MWCNTs) as adsorbent prior to MEEKC. Separations of selected isoflavones namely daidzein, genistein and formononetin by MEEKC were carried out using fresh daily-prepared microemulsion background electrolyte (BGE). The optimized MEEKC conditions for the separation of isoflavones were 4 mM borate buffer pH 8.5, 6.6% (w/v) 1-butanol, 0.9% (w/v) sodium dodecyl sulphate, 0.75% (w/v) ethyl acetate, 3% (w/v) acetonitrile at 3 s injection time, 27 kV and 35 °C. Meanwhile, the optimum D-μ-SPE conditions were 5 mg of MWCNTs and 300 µL of methanol as desorption solvent. Under the optimized conditions, the developed D-µ-SPE-MEEKC method showed good linearity in the concentration range of 1-10 mg/L with coefficients of determination (r2) > 0.99 and limits of detection of 0.27-0.95 mg/L. The method was successfully applied to the determination of isoflavones in five soybean products namely soy supplement, tofu, tempeh, egg tofu and fujook and good recoveries were obtained in the range of 74.5-112.5% with RSDs of < 3%. The method has proved to be simple and offers low consumption of organic solvent and relatively short analysis time, thus it is a potentially viable green alternative method for extraction and determination of isoflavones in soybean products

Synthesis and characterization of polydimethylsiloxane-cyanopropyltriethoxysilane-derived hybrid coating for stir bar sorptive extraction

New inorganic-organic hybrid materials were synthesized by hydrolysis and condensation of cyanopropyltriethoxysilane (CNPrTEOS) and polydimethylsiloxane (PDMS) in the presence of hydrochloric acid, HCl catalyst and methyl trimethylmethoxysilane as precursor via sol-gel method and coated on glass encased stir bar for use in stir bar sorptive extraction (SBSE). The cyano part provides polar moiety, which may improve the extraction of polar analytes. The physico-chemical properties and extraction ability of PDMS-CNPrTEOS-derived hybrid coatings can be fine tuned via manipulation of solvents (tetrahydrofuran (THF)-based and dichloromethane (DCM)-based) and PDMS-CNPrTEOS molar concentrations during the sol synthesis. Clear, homogeneous PDMS-CNPrTEOS-derived hybrid sols were obtained using THF and DCM at optimized molar ratios. The optimized molar ratios of THF:CNPrTEOS and THF:PDMS were 5:1 and 25:1, respectively. The optimized molar ratios of DCM:CNPrTEOS and DCM:PDMS were 10:1 and 70:1, respectively. FTIR spectrum showed that the intensity of the CN peak increased with increasing content of CNPrTEOS in the PDMS;CNPrTEOS-derived hybrid. The Field Emission Scanning Electron micrographs of prepared coatings revealed smooth, homogenous surfaces and crack-free coatings with film thickness of 200 nm to 2.5 mu m attributing to different solvent types. All coatings prepared were thermally stable at temperature higher than 200 A degrees C. The DCM-based PDMS-CNPrTEOS-derived coating shows more advantages in terms of physical characteristics and extraction ability compared to THF-based PDMS-CNPrTEOS-derived coatings due to higher cyano part content and its thicker coating. The PDMS-CNPrTEOS-derived hybrid coatings can be used as extraction sorbent for analysis of non steroidal anti-inflammatory drugs namely ketoprofen and diclofenac sodium in SBSE

Determination of selected heavy metal concentrations in unregistered face whitening creams sold in Johor Bahru, Johor, Malaysia by using inductively coupled plasma optical emission spectroscopy and their health risk assessment

This study determined the concentrations of arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) in unregistered face whitening creams that are commonly accessible in Johor Bahru (Johor, Malaysia) local markets. Three separate brands (marked as Brand X, Brand Y and Brand Z) of unregistered face whitening creams were chosen. Each brand was purchased with five replicates. A total of 15 samples were purchased from five different locations. Microwave digestion process was used to digest the heavy metals out from the cream matrices, and later analysed by using inductively coupled plasma-optical emission spectroscopy (ICP-OES) method. Results showed slightly higher Hg concentrations in Brand X (6.5 ppm), whereas Pb concentration in the whitening creams were below the acceptable limit (ranged 0.1–0.4 ppm) as set by the Malaysia National Pharmaceutical Regulation Act (NPRA). Nevertheless, the Pb concentration exceeded the limit set by the World Health Organisation (WHO) for daily use, which is 0.05 ppm. Besides, As and Cd were not detected significantly in all brands. Health risk assessment for all samples identified with heavy metals, in consideration of the excessive mercury concentration and based on HRI results, could not ignore the fact that Brand X holds possible harmful effects on human health, following its use

Synthesis and characterization of polydimethylsiloxane-cyanopropyltriethoxysilane-derived hybrid coating for stir bar sorptive extraction

New inorganic–organic hybrid materials were synthesized by hydrolysis and condensation of cyanopropyltriethoxysilane (CNPrTEOS) and polydimethylsiloxane (PDMS) in the presence of hydrochloric acid, HCl catalyst and methyl trimethylmethoxysilane as precursor via sol–gel method and coated on glass encased stir bar for use in stir bar sorptive extraction (SBSE). The cyano part provides polar moiety, which may improve the extraction of polar analytes. The physico-chemical properties and extraction ability of PDMS-CNPrTEOS-derived hybrid coatings can be fine tuned via manipulation of solvents (tetrahydrofuran (THF)-based and dichloromethane (DCM)-based) and PDMS-CNPrTEOS molar concentrations during the sol synthesis. Clear, homogeneous PDMS-CNPrTEOS-derived hybrid sols were obtained using THF and DCM at optimized molar ratios. The optimized molar ratios of THF:CNPrTEOS and THF:PDMS were 5:1 and 25:1, respectively. The optimized molar ratios of DCM:CNPrTEOS and DCM:PDMS were 10:1 and 70:1, respectively. FTIR spectrum showed that the intensity of the CN peak increased with increasing content of CNPrTEOS in the PDMS;CNPrTEOS-derived hybrid. The Field Emission Scanning Electron micrographs of prepared coatings revealed smooth, homogenous surfaces and crack-free coatings with film thickness of 200 nm to 2.5 μm attributing to different solvent types. All coatings prepared were thermally stable at temperature higher than 200 °C. The DCM-based PDMS-CNPrTEOS-derived coating shows more advantages in terms of physical characteristics and extraction ability compared to THF-based PDMS-CNPrTEOS-derived coatings due to higher cyano part content and its thicker coating. The PDMS-CNPrTEOS-derived hybrid coatings can be used as extraction sorbent for analysis of non steroidal anti-inflammatory drugs namely ketoprofen and diclofenac sodium in SBSE

Box-Behnken Experimental Design for the Synthesis of Magnetite-Polypyrrole Composite for the Magnetic Solid Phase Extraction of Non-steroidal Anti-inflammatory Drug Residues

A magnetite–polypyrrole composite adsorbent was synthesized and applied for the magnetic solid phase extraction of three non-steroidal anti-inflammatory drugs in aqueous solution and systematically investigated using Box–Behnken design. The synthesized composite adsorbent was characterized using Fourier-transform infrared spectroscopy, transmission electron microscopy, the Brunauer–Emmett–Teller method, vibrating sample magnetometry, and X-ray diffraction. The material was successfully modeled by Box–Behnken design (R2 = 0.94–0.98, p value: <0.001%) by monitoring the extraction efficiencies of naproxen, diclofenac sodium, and mefenamic acid. The analytes were determined using high-performance liquid chromatography with ultraviolet detection. The polymerization time was found to be the most significant factor, followed by amount of oxidant and monomer in the synthesis of the composite with a fixed Fe3O4 mass. Box–Behnken design was employed for the optimization of four parameters affecting the magnetic solid phase extraction: sample pH, salt addition, adsorption, and desorption time (R2 = 0.88–0.94). The optimized conditions for the procedure were validated, providing low detection limits (0.9–3.5 µg L−1) with good reproducibility (<7.16% relative standard deviation) and excellent recoveries (97.87–100.49%) for tap, river, and wastewater samples. The synthesized adsorbent demonstrated good adsorption efficiency for the simultaneous determination of the non-steroidal anti-inflammatory drug residues

Toxic metals in perna viridis mussel and surface seawater in Pasir Gudang coastal area, Malaysia, and its health implications

Contamination of toxic metals in P. viridis mussels has been prevalently reported; hence, health risk assessment for consuming this aquaculture product as well as the surrounding surface seawater at its harvesting sites appears relevant. Since Kampung Pasir Puteh, Pasir Gudang is the major harvesting site in Malaysia, and because the last heavy metal assessment was done in 2009, its current status remains unclear. Herein, flame atomic absorption spectrometry and flow injection mercury/hydride system were used to determine the concentrations of Pb, Cd, Cu and total Hg in P. viridis mussels and surface seawater (January–March 2015), respectively. Significantly higher concentrations of these metals were found in P. viridis mussels (p < 0.05) than that of surface seawater samples. The concentrations for Pb (4.27–6.55 μg/g) and Cd (1.55–2.21 μg/g) in P. viridis mussels exceeded the maximum permitted proportion prescribed by the Malaysian law. The concentrations of all metals in surface seawater also violated the Malaysia Marine Water Quality Criteria and Standards. Significant (p < 0.05) and high strength of association (r = 0.787) observed between Pb concentration in P. viridis mussel with the surface seawater indicates its possible application for inferring Pb concentrations in the mussel. Since both the calculated target hazard quotient and hazard index for Pb and Cd exceeded 1, the possible detrimental health impacts on human for consuming P. viridis mussels from this rearing site cannot be ignored. Hence, promoting continuous monitoring programmes and developing efficient toxic metal removal techniques prior to entering the market are required

Magnetic sporopollenin-cyanopropyltriethoxysilane-dispersive micro-solid phase extraction coupled with high performance liquid chromatography for the determination of selected non-steroidal anti-inflammatory drugs in water samples

A facile dispersive-micro-solid phase extraction (D-μ-SPE) method coupled with HPLC for the analysis of selected non-steroidal anti-inflammatory drugs (NSAIDs) in water samples was developed using a newly prepared magnetic sporopollenin-cyanopropyltriethoxysilane (MS-CNPrTEOS) sorbent. Sporopollenin homogenous microparticles of Lycopodium clavatum spores possessed accessible functional groups that facilitated surface modification. Simple modification was performed by functionalization with 3-cyanopropyltriethoxysilane (CNPrTEOS) and magnetite was introduced onto the biopolymer to simplify the extraction process. MS-CNPrTEOS was identified by infrared spectrometrywhile the morphology and the magnetic property were confirmed by scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), respectively. To maximize the extraction performance of ketoprofen, ibuprofen, diclofenac and mefenamic acid using the proposed MS-CNPrTEOS, important D-μ-SPE parameters were comprehensively optimized. The optimum extraction conditions were sorbent amount, 40 mg; extraction time, 5 min; desorption time; 5 min; sample volume, 15 mL; sample pH 2.0; and salt addition, 2.5% (w/v). The feasibility of the developed method was evaluated using spiked tap water, lake water, river water and waste water samples. Results showed that ketoprofen and ibuprofen were linear in the range of 1.0–1000 μg L−1 whilst diclofenac and mefenamic acid were linear in the range 0.8–500 μg L−1. The results also showed good detection limits for the studied NSAIDs in the range of 0.21–0.51 μg L−1 and good recoveries for spiked water samples in the range of 85.1–106.4%. The MS-CNPrTEOS proved a promising dispersive sorbent and applicable to facile and rapid assay of NSAIDs in water samples