Wan Nazihah Wan Ibrahim
Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia

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Alginate-Graphene Oxide Biocomposite Sorbent for Rapid and Selective Extraction of Non-Steroidal Anti-Inflammatory Drugs Using Micro-Solid Phase Extraction Mohammad Salim Tabish; Nor Suhaila Mohamad Hanapi; Wan Nazihah Wan Ibrahim; Nor’ashikin Saim; Noorfatimah Yahaya
Indonesian Journal of Chemistry Vol 19, No 3 (2019)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (18.127 KB) | DOI: 10.22146/ijc.38168

Abstract

In this work, a bio-composite sorbent, alginate incorporated graphene oxide (Alg/GO) is prepared for the micro solid phase extraction of non-steroidal anti-inflammatory drugs (NSAIDs) from water samples. The sorbent was prepared in a suspended solution form at a ratio of 0.3:1 (w/v %) of graphene oxide (GO) and alginate (Alg). The chemical structure, morphology and surface area of the composite beads were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and Brunauer–Emmett–Teller (BET). GO showed good miscibility and well dispersion through intermolecular hydrogen bonds and electrostatic interactions within the Alg matrix. The synthesized sorbent was applied for the determination of the selected drugs in a tap water sample using micro-solid phase extraction technique and was analyzed by high-performance liquid chromatography-ultraviolet detector (HPLC-UV). The results showed good linearity in the range of 10–1000 µg L–1 with correlation coefficients (r ≥ 0.9979), low detection limits (LOD) between 3.1–4.6 µg L–1, excellent relative recoveries in the range of 99.6–102.1% and good reproducibility (RSD ≤ 3.9%). Thus, these validated results showed that Alg/GO could be potential and useful as a bio-composite sorbent for micro-solid phase extraction for the analysis of targeted drugs from aqueous matrices.
Magnetic Mesoporous Silica Composite for Enhanced Preconcentration of Selected Organophosphorus Pesticides in Fruits Nur Husna Zainal Abidin; Wan Nazihah Wan Ibrahim; Nor Suhaila Mohamad Hanapi; Nor’ashikin Saim
Indonesian Journal of Chemistry Vol 20, No 4 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (716.695 KB) | DOI: 10.22146/ijc.42935

Abstract

In the present work, MCM-41 coated magnetic particles (Fe3O4-MCM-41) composite was synthesized and employed as an effective adsorbent in magnetic solid phase extraction (MSPE) of three selected organophosphorus pesticides (OPPs) namely chlorpyrifos, diazinon and parathion methyl from grape and strawberry samples prior to high performance liquid chromatography with UV detection (HPLC-UV). The synthesized sorbent was physicochemically and morphologically characterized via Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and N2 adsorption analysis. The main parameters on the extraction efficiency of selected OPPs, including extraction time, desorption solvent, desorption time, and sorbent dosage, were thoroughly optimized. Compared to MCM-41 sorbent, the newly synthesized Fe3O4-MCM-41 adsorbent shows a linear response (0.1-5.00 mg L–1) with good determination coefficients ranging from 0.9900 to 0.9980, low limits detection (LODs), 0.02-0.15 mg L–1 and low limit quantifications (LOQs), 0.06-0.40 mg L–1. The precision as relative standard deviation (%RSD) of the proposed MSPE method was studied at low and high concentration (0.1-5.0 mg L–1) based on intra-day (1.0 to 6.0%, n = 3) and inter-day (1.0 to 7.0%, n = 3), respectively. Fruit matrices were used to assess the field applicability of the sorbents. Comparatively, Fe3O4-MCM-41 achieved excellent percent recovery (85–120%) compared to the MCM-41 (70–110%). The result revealed that the Fe3O4-MCM-41 composite was efficient sorbent with good capability for the preconcentration of selected OPPs from fruit samples.
Adsorption-Desorption Profile of Methylene Blue Dye on Raw and Acid Activated Kaolinite Nurul Ain Safiqah Md Sandollah; Sheikh Ahmad Izaddin Sheikh Mohd Ghazali; Wan Nazihah Wan Ibrahim; Ruhaida Rusmin
Indonesian Journal of Chemistry Vol 20, No 4 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (19.55 KB) | DOI: 10.22146/ijc.43552

Abstract

The efficiencies of raw (RK) and acid activated (0.5 M AAK) kaolinite clay minerals to remove methylene blue (MB) dyes in aqueous solution were investigated and compared. The 0.5 M AAK was prepared by treatment of RK in dilute 0.5 M HCl aqueous solution under reflux. Kaolinite adsorbents were characterized and their MB removal performances were evaluated via the batch method. MB desorption from spent kaolinites was investigated at pH 4 to 8. The MB removal was increased with increasing initial dye concentration, agitation speed and adsorbent dosage in 60 min reaction time at pH 6. Both kaolinites showed high MB removal (up to 97%). The Freundlich model has the best-fit equilibrium adsorption isotherm model for RK and 0.5 M AAK. The kinetic data for both adsorbents showed strong agreement with the pseudo second order kinetic model (r2 > 0.98). Nevertheless, the spent RK adsorbent demonstrated a significant higher MB retention than 0.5 M AAK in desorption experiments. Kaolinite clays have great potential as cost-effective materials for dyes removal in wastewater treatment.
Selective Determination of Acidic Drugs in Water Samples Using Online Solid Phase Extraction Liquid Chromatography with Alginate Incorporated Multi-Walled Carbon Nanotubes as Extraction Sorbent Nurzaimah Zaini @ Othman; Nor Suhaila Mohamad Hanapi; Nor’ashikin Saim; Wan Nazihah Wan Ibrahim; Ahmad Lutfi Anis
Indonesian Journal of Chemistry Vol 20, No 5 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (20.631 KB) | DOI: 10.22146/ijc.43703

Abstract

A rapid and effective method is developed for selective determination of five selected acidic drugs (salicylic acid, naproxen, diclofenac, ibuprofen and mefenamic acid) in water samples by using online solid phase extraction (Online-SPE) prior to liquid chromatography diode array detector (LC-DAD) analysis. In this study, Alginate incorporated multi-walled carbon nanotubes (Alg-MWCNT) beads were prepared and utilized as solid phase extraction sorbent. Optimization of online SPE-LC operating parameters such as valve switching time, composition of acetonitrile and buffer pH was conducted using Box-Behnken Design of Response Surface Methodology (RSM) to evaluate the interactive effects of these three variables. Under the optimized conditions (valve switching time: 1.5 min, composition of acetonitrile: MSA, 60:40 and buffer pH: pH 2), the method showed good linearity (1–500 μg L−1) with coefficient of determination (R2) of 0.9971–0.9996 and low limits of detection ≤ 0.018 µg L–1. The method showed high relative recoveries in the range of 75–110% for river water and tap water samples, respectively with RSDs of ≤ 7.8 (n = 3). This method was successfully applied to the determination of acidic drugs in river and tap water samples. In addition, Alg-MWCNT sorbent offered high degree of selectivity and efficiency for online SPE-LC-DAD analysis.