Percentage Recovery Values Research Articles

Vortex-Assisted Magnetic Solid-Phase Extraction of Heavy Metals in Water and Food Samples Using Iron Oxide Nanoparticle-Impregnated Carboxymethyl-β-Cyclodextrin.

The excessive accumulation of heavy metals has adverse effects on the human body. Here, magnetic iron oxide-impregnated carboxymethyl-β-cyclodextrin was synthesized. The synthesized material was employed as a magnetic solid-phase extracting adsorbent for specific heavy metals like lead (Pb), nickel (Ni), copper (Cu), and cobalt (Co). Characterization was performed by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller, and Fourier-transform infrared spectroscopy. The analytical merits, like detection limits (Pb: 1.38ng/mL, Ni: 0.5ng/mL, Co: 0.14ng/mL, and Cu: 0.55ng/mL) andquantification limits (Pb: 4.14ng/mL, Ni: 1.62ng/mL, Co: 1.85ng/mL, and Cu: 1.82ng/mL) were calculated. Similarly, the preconcentration and enhancement factors (15) and relative standard deviation (Pb: 3.5, Ni: 0.92, Co: 2.7, and Cu: 1.5) were also calculated. The interfering study shows that the method is highly selective. For validation, it was applied to certified reference materials such as the Institute of Nuclear Chemistry and Technology ornamental Basma tobacco leaves and trace metal double addition 63.4 environmental water with good percent recovery values (92%-99%). Real water and food samples were also used with satisfactory (90%-99%) recovery results.

Nessler Method Verification for Determining Ammonia in Shrimp Pond Wastewater and Its Application in the Ammonia Adsorption Test with Lampung Natural Zeolite

Ammonia levels exceeding 0.50 mg/L can threaten organisms in aquatic environments. The Nessler method is one of the ammonia analysis methods based on the reaction between ammonia in a basic solution and Nessler reagent (K<sub>2</sub>HgI<sub>4</sub>), forming a colloidal dispersion with a brownish-yellow colour. The colour intensity is determined by spectrophotometry. This research aims to verify the Nessler method for determining ammonia levels in shrimp pond wastewater. The research results indicate that the Nessler method shows good linearity in the range of ammonia concentrations from 1 to 5 mg/L, with a correlation coefficient (R<sup>2</sup>) value of 0.9962. The precision value was determined from repeatability, expressed as %RSD (Relative Standard Deviation), i.e., 1.92%, and it meets acceptance criteria, which should be less than 0.5 of the Horwitz RSD. The accuracy obtained from the standard addition method provides a percentage recovery value of 99.25%, meeting the AOAC acceptance criteria. The detection limit and quantification limit of the technique are 0.3883 mg/L and 1.2943 mg/L, respectively. The verified method is then applied to analyze shrimp pond wastewater samples from Sriminosari Village, East Lampung, resulting in an ammonia concentration of 1.52 mg/L. The ammonia levels were then reduced by adsorption with natural zeolite Lampung, decreasing ammonia levels by 20.30%. Meanwhile, adsorption with an activated zeolite reduced the ammonia levels by 45.30%.

Efficient and environmentally friendly spectrofluorimetric determination of cariprazine: An analytical and green chemistry approach.

Cariprazine represents a new generation of antipsychotic medication, characterized by its heightened affinity for the D3 receptor. It has recently obtained approval as an adjunctive treatment option for patients diagnosed with major depressive disorder. In this study, a novel approach utilizing fluorescence spectroscopy was developed to analyze cariprazine. The methodology involves the transformation of cariprazine into a fluorescent compound by means of chemical derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl). Following excitation at 470 nm, the fluorescent derivative displayed peak fluorescence emission at 550 nm. The factors influencing the derivatization process were optimized. Upon reaching the optimal reaction conditions, a linear correlation (r2=0.9995) was observed between the fluorescence intensity and concentrations of cariprazine ranging from 20 to 400 ng/ml. Detection and quantitation limits were determined to be 5.85 and 17.74 ng/ml, respectively. The approach was accurate and precise, with percent recovery values ranging from 98.14% to 99.91% and relative standard deviations of less than 2%. Application of the method to the analysis of cariprazine in bulk and commercial capsules forms yielded accurate results. Moreover, adherence to environmentally friendly analytical practices was evident through alignment with the principles of green analysis, as demonstrated by the analytical eco-scale, AGREE, and GAPI greenness assessment tools.

Sensitive electrochemical determination of 3-nitro-1,2,4-triazol-5-one (NTO) by the gold nanoparticles-decorated glassy carbon and smartphone-integrated screen-printed electrodes based on polyethyleneimine linked with crosslinking agent glutaric dialdehyde

Rapid and sensitive voltammetric methods for 3-nitro-1,2,4-triazol-5-one (NTO) determination are scarce in the literature. In the present research, we reported a crosslinked polyelectrolyte-based modified electrode decorated with gold nanoparticles that can be easily formed on the surfaces of both screen-printed electrodes (SPEs) and glassy carbon electrodes (GCEs) for the first time, as well as a voltammetric method for the electrochemical determination of NTO. Cobalt-amine sites formed between PEI and cobalt(II)-acetylacetonate (CoAcAc, an electrocatalyst) are used as a redox mediator. Electrochemical reduction of NTO in the concentration range of 1.3–13 mg L−1 was carried out by both the developed DPV method and a smartphone application. LOD and LOQ values were found to be 0.4 mg L−1 and 1.25 mg L−1 for the developed DPV method and 0.26 mg L−1 and 0.82 mg L−1 for the smartphone implementations, respectively. By taking advantage of the restricted solubility of some other nitro-explosives in water, the solvent medium and the pH of the supporting electrolyte (the pH value at which NTO exists in anionic form, not valid for other explosives) were optimized. In the presence of other nitro explosives, such as trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), 2,4-dinitro toluene (DNT), and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), the percentage recovery values range from 90.1 to 105.2 % according to the DPV results measured in admixtures with NTO. Surface morphologies of the modified electrode were characterized using scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR), whereas electrochemical studies were performed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The detection method proposed was not adversely affected by common soil ions as well as detergents, sugar, sweeteners, caffeine, and paracetamol-based painkillers as camouflage materials for explosives, the negative impacts of which were either nonexistent or eliminable.

Kinerja Analitik Mikrokapsul Magnetit - Alginat (MNPs-ALG) untuk Analisis Ion Logam Cu(II) dan Aplikasinya pada Sampel Alam

Research has been carried out regarding the synthesis of Magnetite-Alginate microcapsules (MNPs-ALG) and applied to Cu (II) metal ions. The nature of magnetic nanoparticles, Fe3O4 which easily form aggregations can be overcome by this encapsulation process, but a very efficient separation process is also very much needed in the analytical separation process.The process of making magnetite nanoparticle compounds is carried out first using FeCl2.4H2O and FeCl3.6H2O and adding concentrated ammonia at a temperature of 90οC until the solution becomes blackish in color. The dry magnetite, Fe3O4, nanoparticles were then dissolved in distilled water and thickened with Na-Alginate then dropped slowly into a 1 M CaCl2 solution. The results of characterization using SEM showed that there were differences in morphology before and after contact, and there was 0.98% mass of Cu elements on the EDS results.The microcapsule adsorption optimization test gave results for the best adsorption percentage >90% on a mass variation of magnetite (MNPs) of 0.3 grams; pH 5; contact time of 30 minutes and retention capacity of 185.95 mg/gram, at a Cu(II) concentration of 800 ppm. Analytical performance shows the best results with linearity parameters with a correlation coefficient of 0.999; the detection limit and quantitation limit are 0.0516 ppb and 0.1720 ppb with a lifetime of four times. The application of samples in the form of river water samples shows a percent recovery value of around >90%, indicating that there is no matrix that significantly influences the measurements.

Simultaneous biosorption of acid violet and reactive yellow dyes by Cladosporium cladosporioides

The synthetic dye mixture of Acid Violet 90 and Reactive Yellow 145 was treated with dead Cladosporium cladosporioides biomass. The individual concentrations were calculated with the first-order derivative spectrophotometric method. The calibration curves were plotted at wavelengths of 578.4 nm and 318.2 nm in the derivative spectrum for Acid Violet 90 and Reactive Yellow 145, respectively. The calculated limit of quantitation value is ~ 2.5 mg/L for Acid Violet 90 and ~ 1.5 mg/L for Reactive Yellow 145. The achieved mean recovery percentage values are around 100%. The highest removal efficiency (100%) was obtained for both dyes at pH 4 using 0.25 g biomass and 50 mg/L of each dye in 60 min reaction time with 150 rpm shaking speed. The hydrochloric acid solution was used for biomass regeneration, and the removal efficiencies remained at 99% and 89% for Acid Violet 90 and Reactive Yellow 145 in the third cycle.Graphical abstractBiosorption process

Porous Zinc Oxide and Functionalized Multiwalled Carbon Nanotubes Composite as Electrode Material for Enhanced Electrochemical Sensing of an Anticancer Drug, Dasatinib

An anticancer drug, dasatinib (DAS), is used to treat prostate cancer, chronic myelogenous leukaemia, and acute lymphoblastic leukaemia. In the present work, we describe the preparation of zinc oxide (ZnO) nanoparticles (NPs) using Averrhoa bilimbi leaf extract. These ZnO NPs were combined with functionalized multi-walled carbon nanotubes (f-MWCNT) to prepare a ZnO@f-MWCNT nanocomposite for electrochemical sensing of DAS. The prepared electrode materials, ZnO NPs, f-MWCNT, and ZnO@f-MWCNT, were characterised by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), the Fourier-transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), zeta potential, and the dynamic light scattering (DLS) techniques. DAS exhibited a significant enhancement (18-fold) in the oxidation peak current at ZnO@f-MWCNT, 10-fold at f-MWCNT, and 6-fold at ZnO NPs as compared to that at bare GCE. Under optimised conditions, a linear relationship was noticed among the peak current and concentration of DAS in the range of 0.03–82.65 μM and 0.01–122.45 μM for the differential pulse voltammetric (DPV), and square wave voltammetric (SWV) methods, respectively. Further, the applicability of the proposed sensor was demonstrated by analysing pharmaceutical and biological samples containing DAS. Higher percentage recovery values, and lower relative standard deviation (RSD) values highlighted the accuracy and precision proposed electrochemical methods.

A simple and effective graphene oxide-zinc oxide nanocomposite based solid phase extraction method for the determination of cadmium in tea matrix at trace levels by flame atomic absorption spectrophotometry

In this study, an easy, environmentally friendly and fast approach was introduced for the synthesis of GO-ZnO nanocomposite (NC). Characterization tools including X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to verify the synthesized nanomaterial. Afterward, the combination of GO-ZnO NC based dispersive solid phase microextraction (dSPME) and flame atomic absorption spectrophotometry (FAAS) was used to preconcentrate and determine Cd with high precision and accuracy. In the optimization experiments, all parameters that affecting extraction yield were optimized. Limit of quantification (LOQ) and detection (LOD) values for the GO-ZnO NC-dSPME-FAAS system were calculated as 12.76 µg L−1 and 3.83 µg L−1, respectively. In order to check the applicability and accuracy of the developed method, recovery experiments were performed on three different hibiscus tea samples. The percent recovery values calculated from the spike experiments were in the range of 84 – 111%.

A low-cost voltammetric sensor based on multi-walled carbon nanotubes for highly sensitive and accurate determination of nanomolar levels of the anticancer drug Ribociclib in bulk and biological fluids.

In this study, we present the development and comprehensive characterization of the first electrochemical sensor utilizing multi-walled carbon nanotubes (MWCNTs) for the sensitive and precise detection of Ribociclib (RIBO), an important anticancer drug. The sensor underwent systematic optimization, focusing on critical parameters such as pH, deposition potential, and cumulative time to enhance its electrocatalytic activity and expand the linear range for RIBO determination. The MWCNTs/GCE sensor exhibited excellent reproducibility and repeatability, ensuring reliable and consistent results. The applicability and feasibility of the sensor for real sample analysis were extensively evaluated by analyzing human serum, urine, and tablet samples using the standard addition method. The obtained percent recovery values demonstrated the sensor's exceptional accuracy and precision. Furthermore, interference studies revealed the sensor's remarkable selectivity, with minimal impact from common interfering substances. The developed sensor displayed a wide linear range of 0.01 μM to 5.0 μM, with a limit of detection (LOD) and limit of quantification (LOQ) calculated to be 0.69 nM and 2.31 nM, respectively, affirming its high sensitivity for detecting low RIBO concentrations. The MWCNTs/GCE sensor demonstrates substantial promise for diverse practical applications with its simplicity, cost-effectiveness, and excellent analytical performance.

Sulfide-modified magnetic titanium dioxide microparticles for the adsorption and solid-phase extraction of toxic metals in aqueous samples

In this work, sulfide-modified magnetic titanium dioxide microparticles (magnetic TiO2-µPs@S) were synthesized and studied for adsorption-based removal and extraction of Cd(II), Co(II), Cu(II), Mn(II), and Ni(II) ions in aqueous solutions before FAAS analysis. The magnetic TiO2-µPs@S was well characterized by UV-vis, FTIR, XRD, SEM, and EDS techniques, and the material was well functionalized, pure, and had a slightly rod-like morphology. Under optimized conditions, initial concentration of 10 mg/L, sample solution pH of 7, adsorbent dose of 0.5 g/L, agitation speed of 200 rpm, and contact time of 45 min, the magnetic TiO2-µPs@S exhibited an adsorption capacity of 24.0, 34.9, 37.6, 38.5, and 27.9 mg/g for Cd(II), Co(II), Cu(II), Mn(II), and Ni(II), respectively. Then after, the desorption experiment was conducted using 5 mL of 0.2 M HNO3 as an eluting solvent. The method showed excellent linearity (R 2 ≥ 0.998) in 0.05–10 mg/L concentration range. The limits of detection and quantification of the developed method were found to be in the range of 0.14–0.81 and 0.47–2.73 µg/L, consecutively, indicating high sensitivity of the proposed method, and <3% RSD was obtained. Furthermore, its practical applicability was assessed on tap water, lake water, and wastewater samples, and satisfactory percent recovery values, 84.5–114%, were acquired. These results indicate the potential applicability of the developed method. In general, the magnetic TiO2-µPs@S can be used as an effective adsorbent for removing heavy metals, and the adsorbent-based solid-phase extraction can be considered a promising technique for extracting and enriching heavy metals from aqueous solutions.

Development of Visible Spectrophotometric Method and its Validation for Dolutegravir in Tablet Dosage Form

Objective: There are several methods for analyzing the same, however, they are time-consuming and costly. We created a new spectrophotometric method for determining Dolutegravir (DLT) in tablet dosage forms that is simple, accurate, and precise. We developed and validated a simple, accurate, and precise colorimetric method for the quantitative analysis of Dolutegravir in bulk and dosage form by ICH recommendations in this study. Methodology: There are several methods for analyzing the same, however, they are time-consuming and costly. We created a new spectrophotometric method for determining Dolutegravir (DLT) in tablet dosage forms that is simple, accurate, and precise. In methanol, the initial stock solution of Dolutegravir was prepared. The method is based on the formation of a blue color chromogen complex from Dolutegravir oxidation-reduction with Ferric chloride in the presence of potassium ferricyanide. Result: The color complex was measured at 710nm. Beers law was observedin the concentration range of 3.5-6.5μg/ml witha coefficient of correlation (R2) was 0.998. The system suitability criteria were found to be within the limits. The LOD and LOQ were found to be 0.91 and 2.47, indicating that the method is sensitive. Conclusion: The relative standard deviation (RSD) and percent recovery values were found to be satisfactory, indicating that the proposed method is suitable, accurate, and precise and that it can be used in routine analysis of Dolutegravir in tablet dosage forms, with relatively low-cost solvents.

Green electrochemical approach for simultaneous quantification of Dapoxetine hydrochloride and Tadalafil integrating design of experiments and functional principal component analysis

To ensure a successful therapy for impotence and erectile ejaculation issues, tablets containing Tadalafil (TD) and Dapoxetine hydrochloride (DP) must be verified for their ingredients. This study presents a green voltammetric technique for the simultaneous determination of DP and TD. The technique is based on the unique electrochemical properties of DP and TD, and it is simple, rapid, and cost-effective. To accomplish this goal, design of experiment (DoE) and functional principle component analysis (FPCA) were applied due to the difficulty of the optimization process. The International Council on Harmonization (ICH) guidelines were used to validate the proposed method, which displayed precision for DP and TD within the concentration range of 6.7–67.0 μg mL−1. The percentage recovery values were (96.83–100.67%) and (98.27–100.90%) for DP and TD respectively. To assess the ecological impact, four greenness evaluation tools were employed, including Eco-Scale Assessment (ESA), Environmental Methods Index (NEMI), Analytical Greenness Calculator (AGREE), and Complex Green Analytical Procedure Index (Complex GAPI). The proposed method was employed on the dosage form and compared statistically to a reported HPLC method, revealing no significant differences at a 95% confidence level. The proposed method is a promising green analytical tool for the simultaneous determination of DP and TD in pharmaceutical dosage forms with good precision and accuracy. Additionally, the method is environmentally friendly, as evidenced by the greenness evaluation results. In addition, this study aims to demonstrate how the latest nonparametric technique for analyzing functional data (curves) can produce reliable results in experimental settings.

Rapid environmentally benign label free detection of heparin using highly fluorescent N,S-CDs sensing probe through a turn-on mechanism

Heparin (HEP) is one of the oldest anticoagulant drugs that currently still in widespread clinical use. It lacks chromophore and not easily derivatized due to its hydrophilic nature. In this work we developed a green, selective, and sensitive fluorescence sensor for detection of HEP in its injection dosage forms. The sensor is composed of nitrogen and sulfur co-doped carbon quantum dots (N,S-CDs) semi quenched by Fe3+. The N,S-CDs were prepared using microwave assisted pyrolysis in 3.5 min and exhibited high emission at 425 nm after excitation at 350 nm with high quantum yield of 96%. Owing to the anionic nature of HEP, it could compete with N,S-CDs for Fe3+ complexation resulting in turning-on the quenched fluorescence. This fluorescence enhancement was linear over a concentration range between 6 and 20 μg/mL (R2 = 0.99) with a limit of detection of 1.41 µg/ml. The accuracy and precision of the proposed sensor were indicated by percentage recovery values between 98% −102% and %RSD less than 2, respectively. Furthermore, the proposed sensor was successfully applied for determination of HEP in injection dosage form. The developed sensor showed excellent greenness on analytical eco-scale (score 93%) and GAPI scale.

Nanosensors: A smart remedy for early detection of clenbuterol contamination in food.

Veterinary drugs which are primarily meant for livestock treatment have now been categorised under potential food contaminant due to its unregulated usage and abuse. Their over usage by animal workers lead to production of contaminated animal-based food products which contain veterinary drug residues. These drugs are also misused as growth promoters to enhance the muscle to fat ratio in human body. This review highlights the misuse of such a veterinary drug; Clenbuterol. In this review, we have comprehensively discussed the usage of nanosensors to detect clenbuterol in food samples. Colorimetric, fluorescent, electrochemical, SERS and electrochemiluminescence are major categories of nanosensors that have been utilized for this purpose. The mechanism through which these nanosensors detect clenbuterol have been discussed in detail. The limit of detection and recovery percentage values of each nanosensor have been compared. This review will impart significant information on various nanosensors for clenbuterol detection in real samples.

Determination of dopamine in blood serum and urine samples by differential pulse voltammetry at an iodine-coated platinum electrode

While platinum electrode shows hyperactivity towards adsorption and surface processes, iodine-coated platinum electrode offers remarkable inertness toward them. Therefore, iodine-coated platinum electrodes lend themselves to probe chemical species in the bulk solution without intervention from adsorption and surface processes. The current work presents utilization of iodine-coated polycrystalline platinum electrode as a voltammetric sensor for determination of dopamine in serum and urine samples. Differential pulse voltammetry (DPV) at iodine coated polycrystalline platinum electrode is the technique of choice whenever higher sensitivity is sought. DPV with a scan rate of 5 mV/s was applied for determination of dopamine in PBS at pH 7. The anodic peak related to dopamine oxidation in the above-mentioned solution was centered at ~0.1V vs. Ag/AgCl quasi reference electrode. The linear range for the developed method was between 1.0 and 100 µM. The anodic peak current showed excellent linearity with dopamine concentration (R2 =0.9977) over the above-mentioned range. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.29 µM and 0.96 µM respectively which attests to the high sensitivity of the developed method. The proposed method was successfully applied to the analysis of dopamine in serum and urine samples. The percent recovery values ranged from 94.4 to 104.5% attesting to the accuracy of the developed method and absence of determinate errors.

New validated Ultra High Performance Liquid Chromatographic method for Estimation of Quercetin

Background: A new Ultra performance liquid chromatographic analytical method was developed and validated for estimation of Quercetin in bulk powder. The reverse phase chromatographic elution using UPLC was carried out in gradient mode on C-18 column (Phenomenex Luna 5 µm, 150 mm X 4.6 mm) as stationary phase utilizing a mobile phase composed of Acetonitrile: 0.1 % formic acid buffer (50:50 v/v) with a flow rate of 1 ml/min and injection volume of 10µl. The analysis was performed at temperature of 400C and detection of eluent was carried out using photo diode array at 371 nm. The newly developed Ultra performance liquid chromatography method was validated in terms of linearity and range, system suitability, specificity, precision, sensitivity, robustness, ruggedness and accuracy as per ICH guidelines. Results: The retention time of quercetin was found to be at 3.9 min with total run time of analysis is 7 minutes. The linearity was observed between the concentration ranges from 0.5 to 16µg/ml with correlation coefficient 0.999. The precision assays values were found to be less than 2% for both the drugs. The Limit of Detection and Limit of Quantification were 0.47µg/ml and 1.44µg/ml for Quercetin. The mean percentage recovery values were found to be within the range of 90-110 %. Conclusion: The proposed method was found to be simple, specific, precise, sensitive, robust, rugged and accurate and can be used for routine quality control analysis of Quercetin.

RP-HPLC Method Development, Validation Including Stability Indicating and Forced Degradation Studies for the Estimation of Pemetrexed in API and Pharmaceutical Dosage Form

Stability indicating analytical RP-HPLC (Reverse Phase- High performance Liquid Chromatography) method was developed for the analysis of the drug in the presence of its degradation products and subsequent validation of Pemetrexed that was conducted in API and pharmaceutical dosage form. Pemetrexed was subjected to different stress conditions as per International Conference on Harmonization (ICH) guidelines, stress conditions applied were including the effect of acid, base, oxidative, hydrolysis, thermal and photolytic degradation conditions. Chromatographic separation of API (Active Pharmaceutical ingredient) was achieved on Water’s HPLC instrument and ODS C18, 250x4.6 mm, 5µm particle size column with gradient elution of 0.1% ortho phosphoric acid buffer: Acetonitrile 80:20 ratio was taken as the eluent (mobile phase). The buffer pH was maintained at 3, the flow rate was 1.0 ml/min and wavelength were detected at 225 nm. The Retention time (RT) of Pemetrexed was Found at 2.9 minutes, column temperature was kept ambient and the runtime was 6 min. System suitability parameters like theoretical plates, tailing factor, and Asymmetry values were showed at 3391, 1.41, and 1.101 respectively. The percentage drug purity was found to be 99.99%. Validation of the method was proved that linear relationship over the range of 25-150 µg/mL, with linear regression curve (correlation coefficient) r2 value was noticed at 0.999 and LOD (limit of detection), LOQ (limit of quantification) values was established at 0.33µg/mL, 0.99µg/mL respectively. Recovery studies carried out at the concentrations of 50%, 100% and 150% with percentage recovery values of 100.06, 99.8 and 99.87 respectively. The precision of intraday was 0.64% and inter-day was 0.95%. Robustness of flow rate and mobile phase was changed even though the method was Robust. Forced degradation studies were also conducted to check the stability and suitability of this method to resolve the degradation products. Method validation was proved to be accurate, precise, linear, repeatable and robust. Thus, the accepted method can be proceeded for the estimation of Pemetrexed in pharmaceutical dosage form in a daily basis, due to their simplicity, suitability, accuracy, robustness and reproducibility.

Determination of Lead(II) and Cadmium(II) in Selected Commercially Available Water‐Based Paints of Ethiopia by Anodic Stripping Voltammetry Using a Bismuth‐Modified Glassy Carbon Electrode

AbstractSince the introduction of bismuth‐modified electrodes in Anodic Stripping Voltammetry, it has been used to determine heavy metals in various matrices. However, most reports focused on water samples due to fewer sample treatment requirements. In this study, Square Wave Anodic Stripping Voltammetry technique with a bismuth‐modified glassy carbon electrode is reported for the simultaneous determination of lead and cadmium content in paints. Analysis of paint samples collected from three industries in Ethiopia showed excellent percent recovery values ranging from 97.99–102.07 %. The Pb and Cd contents in these products have not been reported yet. The limits of detection were 0.06 μmol/L for Pb(II) and 0.13 μmol/L for Cd(II). The concentration of Cd(II) is not in the detectable range (ND) in all paint samples. The concentration Pb(II) in paint samples of DH‐Geda (Green 3.41±0.62 ppm, Red 14.05±0.91 ppm, violate 11.23±1.08 ppm and White 12.04±0.57 ppm), Nefas silk (Green 2.95±0.29 ppm, Red 3.16±0.36 ppm, violate 7.42±0.83 ppm, and White 6.93±0.79 ppm) and Tsehay (Green 4.40±0.67 ppm, Red ND, Violate ND, and White ND). These results are cross‐checked with AAS and the result is almost the same. This method is not significantly influenced by the paint matrix and can be used as an alternative analytical method for the determination of heavy metals in the paint matrix. The amount of Pb(II) and Cd(II) in the given paints are below the permissible levels based on the regulation of Ethiopia (90 ppm for Pb). Therefore, they are safe to use in the country.

Trace cadmium determination in lake water matrix by flame atomic absorption spectrometry after manganese ferrite magnetic nanoparticles‐based dispersive solid phase extraction

AbstractIn this study, manganese ferrite magnetic nanoparticles‐based dispersive solid phase extraction (MF‐MNP‐DSPE) was developed for cadmium determination at trace level by flame atomic absorption spectrometry (FAAS). Manganese ferrite‐based magnetic nanoparticles were synthesized to be used as solid phase extraction sorbent. All the analytical conditions were optimized by univariate optimization approach to achieve high enrichment factors. Under the optimum conditions, limit of detection (LOD) and quantification (LOQ) values of the developed method were recorded as 1.3 and 4.3 µg L−1, respectively. Approximately 135‐fold improvement in the detection power by the MF‐MNP‐DSPE‐FAAS system was recorded over the traditional FAAS system based on LOD comparison. Recovery experiments were performed to test the applicability/accuracy of the developed method with lake water spiked at different concentrations. Percent recovery values were obtained between 87% and 112% by employing the matrix matching calibration strategy and this showed that the developed method is applicable for the determination of cadmium in lake water samples with high accuracy and precision.

FLUOKSETİN VE OLANZAPİNİN EŞ ZAMANLI SPEKTROFOTMETRİK TAYİNİ VE YEŞİL KİMYA UYGULAMALARI

Objective: In our study, the simultaneous determination of fluoxetine (FLX) and olanzapine (OLZ) was performed by absorbance subtraction and absorbance correction spectrophotometric methods. Material and Method: The active substances were determined by choosing the isosbestic point of 232 nm in the absorbance subtraction method and 255 nm and 245 nm wavelengths in the absorbance correction method. The accuracy of the methods was determined by applying the percentage recovery studies to the laboratory mixtures. The percent recovery values were found in the range of 98.1-100.2 for OLZ and 96.8-105.3 for FLX. The concentration range studied was 3.12-15.62 and 3.45-17.28 µg/ml for OLZ and FLX, respectively. Result and Discussion: In the study, two active substances used in antidepressant treatment were determined simultaneously. Today, these active substances used in the treatment have started to be used in combination in order to achieve a better effect of the treatment. Therefore, simultaneous analysis of two active substances becomes important. Two different spectrophotometric methods were used for analysis. The methods have been successfully applied and validated for the simultaneous determination of antidepressant active substances. Since the applied methods do not require pre-separation and can be applied directly, the amount of waste generated is reduced. Environmentally sensitive methods have been applied.