Suprapto Suprapto; Yessy I. Riwayati; Yatim L. Ni’mah
Abstract
In this study, the differential pulse voltammetry (DPV) method was used to simultaneously determine bismuth and copper concentrations. A 25 bismuth and copper mixtures at the designed ratio were measured using the DPV technique. However, the overlapping differential pulse voltammograms obtained made ...
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In this study, the differential pulse voltammetry (DPV) method was used to simultaneously determine bismuth and copper concentrations. A 25 bismuth and copper mixtures at the designed ratio were measured using the DPV technique. However, the overlapping differential pulse voltammograms obtained made it difficult to quantitatively analyze the concentrations based on adaptive peak current selection. To address this issue, the voltammograms were preprocessed using derivatization and peak subtraction. The second derivative voltammogram was found to be highly correlated with the copper-bismuth concentration ratio, resulting in improved fit and prediction accuracy. To further improve the accuracy and precision of the training and prediction results, XGBoost and Gradient Boosting regression models were applied. The XGBoost and Gradient Boosting regression models showed high accuracy and precision with r-squared values of 0.877 and 0.993 for copper, and 0.879 and 0.993 for bismuth, respectively. The mean recoveries of copper were 99.84% and 98.07%, while bismuth recoveries were 93.17% and 90.85% for XGBoost and Gradient Boosting, respectively. Additionally, cross-validation using 10 splits produced a mean score of 45.565 and a mean absolute error of 13.051 for copper, and a mean score of 13.600 and a mean absolute error of 10.920 for bismuth. Overall, the results indicate that the proposed method is an accurate and precise way to simultaneously determine bismuth and copper concentrations.
Abdolhamid Hatefi-Mehrjerdi; ُُSoghra Rafiei Boldaji; Mohammad Reza Yaftian; Hassan Shayani-Jam
Abstract
A novel Buprenorphine (BPR) sensor is fabricated based on nanocomposite film of benzene-1,3-disulfonate anion doped overoxidized polypyrrole/multiwalled carbon modified glassy carbon electrode. The carbon nanotubes were drop-casted on bare electrode, and then thin layer of benzene-1,3-disulfonate-doped ...
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A novel Buprenorphine (BPR) sensor is fabricated based on nanocomposite film of benzene-1,3-disulfonate anion doped overoxidized polypyrrole/multiwalled carbon modified glassy carbon electrode. The carbon nanotubes were drop-casted on bare electrode, and then thin layer of benzene-1,3-disulfonate-doped overoxidized polypyrrole formed electrochemically on it. Effect of experimental conditions involving supporting electrolyte pH, carbon nanotubes suspension drop size, and the number of potential cycles in overoxidized polymerization were optimized by monitoring the voltammetry responses of the modified electrode. Then the optimized modified electrode was used for electrochemical sensing of BPR by differential pulse voltammetry, which exhibited a linear growth with high sensitivity in anodic peak currents at the BPR concentration range of 0.06-40 µM, and a detection limit of 28 nM. Finally, the determination of BPR in urine real samples was performed by the new sensor and satisfactory results obtained.
Arash Mohammadinejad; Mahmoud Ebrahimi; Ali Morsali; Zarrin Es’haghi; Hamed Chegini; Abdolhossein Ebrahimitalab
Volume 3, Issue 1 , March 2016, , Pages 27-37
Abstract
In this work, a carbon paste electrode modified with multiwall carbon nanotubes (MWCNTPE) was used for the sensitive voltammetric determination of acetaminophen (AC) in biological and pharmaceutical samples. The electrochemical behavior of acetaminophen was investigated employing cyclic voltammetry. ...
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In this work, a carbon paste electrode modified with multiwall carbon nanotubes (MWCNTPE) was used for the sensitive voltammetric determination of acetaminophen (AC) in biological and pharmaceutical samples. The electrochemical behavior of acetaminophen was investigated employing cyclic voltammetry. It was revealed that the standard electrode potential of half reaction for AC(O), H+/AC(R) was 0.898 V. under the optimized experimental conditions, the oxidation peak current for acetaminophen was found to vary linearly with concentration range of 0.12 to 99 µM with detection limit of 0.06 µM using differential pulse voltammetry. DFT-B3LYP/6-31G (d,p) and HF/6-31G (d,p) calculations were performed for deoxidized acetaminophen (AC(R)) and its oxidized form (AC(O)). The calculated standard electrode potentials are relatively in agreement with experimental data. This electrode was employed for determination of acetaminophen in hospital waste water, hair, blood and pharmaceutical samples considering its high sensitivity, low detection limit, good reproducibility and its non-existent interference at trace levels in clinical and quality control laboratories.
Zarrin Es’haghi; Fatemeh Moeinpour
Volume 1, Issue 2 , September 2014, , Pages 58-64
Abstract
An efficient separation-preconcentration procedure namely hollow fiber solid/liquid phase microextraction (HF-SLPME) was developed for determination of trace amounts of palladium in water samples by differential pulse voltammetry. In this method, a hybrid sorbent utilizing functionalized nanoparticles ...
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An efficient separation-preconcentration procedure namely hollow fiber solid/liquid phase microextraction (HF-SLPME) was developed for determination of trace amounts of palladium in water samples by differential pulse voltammetry. In this method, a hybrid sorbent utilizing functionalized nanoparticles incorporated in an organic solvent was used as the extractor phase. The nanoparticle dispersed in the organic solvent is held in the pores and lumen of a porous polypropylene hollow fiber. It is in contact directly with the aqueous donor phase. The influence of the various analytical parameters such as pH, kind and amounts of nanoparticle and matrix effects, sample volume, extraction time, etc. were studied for the quantitative recoveries of the analyte ions. Under the optimized experimental conditions, the calibration curves for Pd (II) was linear from 0.1 to 500 ng/mL. The relative standard deviation for seven replicate determinations of 0.1 mg/mL palladium in the standard solutions was 3.95 %. The detection limit based on 3Sb for Pd (II) in the standard solutions was 0.01 ng/mL. The proposed method has been applied for determination of trace amounts of palladium in the real water samples and satisfactory results were obtained.
