scholarly journals Fully Integrated 3D-Printed Electronic Device for the On-Field Determination of Antipsychotic Drug Quetiapine

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4753
Author(s):  
Katerina Ragazou ◽  
Rallis Lougkovois ◽  
Vassiliki Katseli ◽  
Christos Kokkinos
Keyword(s):  
Electronic Device ◽  
Limit Of Detection ◽  
Quetiapine Fumarate ◽  
Fully Integrated ◽  
Pharmaceutical Tablets ◽  
Site Analysis ◽  
Electrochemical Parameters ◽  
One Step ◽  
3D Printed

In this work, we developed a novel all-3D-printed device for the simple determination of quetiapine fumarate (QF) via voltammetric mode. The device was printed through a one-step process by a dual-extruder 3D printer and it features three thermoplastic electrodes (printed from a carbon black-loaded polylactic acid (PLA)) and an electrode holder printed from a non-conductive PLA filament. The integrated 3D-printed device can be printed on-field and it qualifies as a ready-to-use sensor, since it does not require any post-treatment (i.e., modification or activation) before use. The electrochemical parameters, which affect the performance of the sensor in QF determination, were optimized and, under the selected conditions, the quantification of QF was carried out in the concentration range of 5 × 10−7–80 × 10−7 mol × L−1. The limit of detection was 2 × 10−9 mol × L−1, which is lower than that of existing electrochemical QF sensors. The within-device and between-device reproducibility was 4.3% and 6.2% (at 50 × 10−7 mol × L−1 QF level), respectively, demonstrating the satisfactory operational and fabrication reproducibility of the device. Finally, the device was successfully applied for the determination of QF in pharmaceutical tablets and in human urine, justifying its suitability for routine and on-site analysis.

scholarly journals Pitfalls in the Immunochemical Determination of β‑Lactam Antibiotics in Water

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 298
Author(s):  
Alexander Ecke ◽  
Rudolf J. Schneider
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Degree Of Hydrolysis ◽  
Site Analysis ◽  
Antibody Recognition ◽  
Immunochemical Determination ◽  
Key Factor ◽  
Lactam Ring

Contamination of waters with pharmaceuticals is an alarming problem as it may support the evolution of antimicrobial resistance. Therefore, fast and cost-effective analytical methods for potential on-site analysis are desired in order to control the water quality and assure the safety of its use as a source of drinking water. Antibody-based methods, such as the enzyme-linked immunosorbent assay (ELISA), can be helpful in this regard but can also have certain pitfalls in store, depending on the analyte. As shown here for the class of β-lactam antibiotics, hydrolysis of the β‑lactam ring is a key factor in the immunochemical analysis as it influences antibody recognition. With the antibody used in this study, the limit of detection (LOD) in the immunoassay could be significantly reduced by hydrolysis for the five tested penicillins, with the lowest LOD for carbenicillin (0.2 nmol/L) and the greatest impact on penicillins G and V (reduction by 85%). In addition to enhanced quantification, our strategy also provides access to information about the degree of hydrolysis in water samples as shown for the most abundant penicillin amoxicillin.

scholarly journals Determination of Atenolol and Trimetazidine in Pharmaceutical Tablets and Human Urine Using a High Performance Liquid Chromatography-Photo Diode Array Detection Method

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Walaa El-Alfy ◽  
Omnia A. Ismaiel ◽  
Magda Y. El-Mammli ◽  
Abdalla Shalaby
Keyword(s):  
Human Urine ◽  
Limit Of Detection ◽  
Pure Form ◽  
Urine Samples ◽  
Dihydrogen Phosphate ◽  
Simple Liquid ◽  
Pharmaceutical Tablets ◽  
Limit Of Quantitation ◽  
Precision And Accuracy

A simple RP-HPLC-PDA method for determination of atenolol (ATN) and trimetazidine (TMZ) in human urine and tablets has been developed. Analytes were separated on a Caltrex BI column (125× 4.0 mm, 5 μm) with 25mM potassium dihydrogen phosphate pH 3.3, methanol, and acetonitrile mobile phases. The PDA detector was operated at 210 nm for TMZ and 225 nm for ATN and the flow rate was 1.0 mL/ min. Linearity was obtained over a concentration range of (1.0-100 μg/mL) for both analytes in standard solutions and the method was successfully applied for determination of target analytes in their pharmaceutical tablets. Excellent linearity was also obtained over concentration ranges of (0.25-25 μg/mL) and (0.5-25 μg/mL) in human urine for TMZ and ATN, respectively. A simple liquid-liquid extraction was applied for urine sample clean-up and a gradient method was used for chromatographic separation. The lower limit of quantitation (LOQ) was 0.99 and 0.60 μg/mL for ATN and TMZ, respectively. The limit of detection (LOD) was 0.30 and 0.18 μg/mL for ATN and TMZ, respectively. Inter- and intraday precision and accuracy for ATN were within ±1.89% in pure form and within ±2.85% in urine samples. Inter- and intraday precision and accuracy for TMZ were within ± 3.99% in pure form and within ± 3.19% in urine samples.

High Throughput Determination of BTEX by a One-Step Fluorescence Polarization Immunoassay

2005 ◽  
Vol 2 (3) ◽  
pp. 227 ◽  
Author(s):  
Sergei A. Eremin ◽  
Dietmar Knopp ◽  
Reinhard Niessner ◽  
Ji Youn Hong ◽  
Song-Ja Park ◽  
...  
Keyword(s):  
Fluorescence Polarization ◽  
Limit Of Detection ◽  
Petroleum Products ◽  
Cross Reactivity ◽  
Rapid Screening ◽  
Fluorescence Polarization Immunoassay ◽  
Phenylcarboxylic Acids ◽  
One Step ◽  
Benzene Toluene

Environmental Context.Benzene, toluene, ethylbenzene, and xylenes (BTEX) are used as solvents in paints and coatings and are constituents of petroleum products. BTEX can contaminate air, water or soil and is toxic; benzene, in particular, is a recognized human carcinogen. Most existing methods for detecting BTEX are time-consuming, complicated and very expensive for routine screening. A rapid immunoassay of BTEX is presented that greatly simplifies environmental monitoring of water contamination. Abstract.For the rapid screening of BTEX (benzene, toluene, ethylbenzene, xylenes), a fluorescence polarization immunoassay (FPIA) was developed using the fluorescence polarization analyzer Abbott TDx. Several fluorescence-labelled tracers were synthesized by binding ethylenediamine fluorescein thiocarbamyl (EDF) to various substituted phenylcarboxylic acids. The binding of 27 tracers with two antisera that can be considered as class-specific for BTEX was investigated to select optimal tracer–antibody pairs. Significant differences were found in binding, titer, sensitivity, and assay kinetics. A best pair of anti-BTEX antiserum and EDF-labelled p-tolylacetic acid tracer was selected for FPIA. To simplify the method, an immunocomplex single reagent was prepared to detect BTEX by a one-step FPIA. One-step FPIA is a rapid homogeneous type of immunoassay that has only one pipetting step, does not need separation of free and bound analyte and can be performed at room temperature. The within-run coefficient of variation was ranged between 3.4% and 5.7%. Furthermore, if the measurement can be done at constant temperature, standards for every assay run are unnecessary. Cross-reactivity studies of petroleum compounds and a BTEX mixture indicated that p-xylene was most reactive with a limit of detection (LOD) of 0.22 µg mL−1 in 50 µL of sample. The LOD for toluene and benzene was 2.1 and 11 µg mL−1 respectively. The immunocomplex single reagent has proven to be significantly more stable than the corresponding solutions of antibody and tracer.

scholarly journals Extractive spectrophotometric determination of Quetiapine fumarate in pharmaceuticals and human urine using calmagite as an ion-pair reagent

2011 ◽  
Vol 17 (3) ◽  
pp. 259-267 ◽  
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiahf ◽  
Basavaiah Vinay
Keyword(s):  
Human Urine ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Official Method ◽  
Quetiapine Fumarate ◽  
Relative Standard ◽  
Significant Difference ◽  
Comparison Of The Results

Quetiapine fumarate (QTF) is an antipsychotic drug belonging to the benzisoxazole derivatives indicated for the treatment of schizophrenia. A sensitive and selective method based on dichloromethane-extractable ion-pair of QTF with calmagite (CGT), which exhibited an absorption maximum at 490 nm, is described. At this wavelength, Beer?s law is obeyed over the concentration range of 3.0 - 30.0 ?g ml-1. The apparent molar absorptivity, limit of detection (LOD) and quantitation (LOQ) values are 1.32 ? 104 l mol-1 cm-1, 0.27 and 0.81 ?g ml-1 respectively. The reaction is extremely rapid at room temperature and the absorbance values remain unchanged upto 19 h. The precision results, expressed as intra-day and inter-day relative standard deviation values, are satisfactory (RSD ? 2.2%). The accuracy is satisfactory as well (RE ? 2.44%). The method was successfully applied to the determination of QTF in pharmaceuticals and spiked human urine with satisfactory results. No interference was observed from common pharmaceutical adjuvants in tablets. Statistical comparison of the results with official method showed an excellent agreement and indicated no significant difference in precision.

scholarly journals Smartphone-Based Chemiluminescent Origami µPAD for the Rapid Assessment of Glucose Blood Levels

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 381
Author(s):  
Donato Calabria ◽  
Martina Zangheri ◽  
Ilaria Trozzi ◽  
Elisa Lazzarini ◽  
Andrea Pace ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Rapid Assessment ◽  
Blood Levels ◽  
Blood Samples ◽  
3D Printed ◽  
Diagnostic Applications ◽  
Catalyzed Oxidation

Microfluidic paper analytical devices (µPADs) represent one of the most appealing trends in the development of simple and inexpensive analytical systems for diagnostic applications at the point of care (POC). Herein, we describe a smartphone-based origami µPAD for the quantitative determination of glucose in blood samples based on the glucose oxidase-catalyzed oxidation of glucose leading to hydrogen peroxide, which is then detected by means of the luminol/hexacyanoferrate(III) chemiluminescent (CL) system. By exploiting the foldable µPAD format, a two-step analytical procedure has been implemented. First, the diluted blood sample was added, and hydrogen peroxide was accumulated, then the biosensor was folded, and a transport buffer was added to bring hydrogen peroxide in contact with CL reagents, thus promoting the CL reaction. To enable POC applicability, the reagents required for the assay were preloaded in the µPAD so that no chemicals handling was required, and a 3D-printed portable device was developed for measuring the CL emission using the smartphone’s CMOS camera. The µPAD was stable for 30-day storage at room temperature and the assay, displaying a limit of detection of 10 µmol L−1, proved able to identify both hypoglycemic and hyperglycemic blood samples in less than 20 min.

scholarly journals Determination of Nicotine in Libyan Smokers' Urine Compared with that of Nonsmokers using Reversed Phase – High Performance Liquid Chromatog-raphy (RP-HPLC)

2019 ◽  
Vol 34 (3) ◽  
pp. 172-180
Author(s):  
Galal Elmanfe ◽  
Suad K. Omar ◽  
Noreldin S.Y. Abdolla ◽  
Amna M. Hassan
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Cost Effective ◽  
High Performance Liquid Chromatog ◽  
Reversed Phase ◽  
Urine Samples ◽  
Average Value ◽  
Limit Of Quantitation ◽  
One Step

The aim of the present study was to evaluate the levels of nicotine in twenty urine samples taken from ten smokers and ten non-smokers in Libya. Each volunteer was required to complete a questionnaire before providing the urine sample. The evaluation of the nicotine concentrations was carried out by means of a simple, rapid, cost effective but reliable, one-step extraction technique-reversed-phase high-performance liquid chromatography which was developed and validated for this purpose. The criteria and factors taken into consideration for this evaluation and validation include the linearity, precision, accuracy, limit of detection, and limit of quantitation. The urine samples from the smokers presented nicotine concentrations in the range of 0.037-1.979 µg/ml, with an average of 0.663 µg/ml. The range of the nicotine concentrations in non-smokers, on the other hand, was from 0.017-1.331 g/ml, where 0.273 µg/ml is the average value. Statistical analyses show that the nicotine concentrations were very significant in the smoker samples in contrast with the nonsmoker samples

A Ratiometric Fluorescent Probe Based on Carbon Dots and Bimetallic Nanoclusters for the Assay of Copper Gluconate and Copper Sulfate

NANO ◽  
2021 ◽  
pp. 2150114
Author(s):  
Yucong Fan ◽  
Weihua Yu ◽  
Yue Hu ◽  
Yunwen Liao ◽  
Xiaohui Jiang ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Molar Ratio ◽  
Cupric Sulfate ◽  
Selective Determination ◽  
Bimetallic Nanoclusters ◽  
One Step ◽  
The One

Doping Ag-enhanced and glutathione-stabilized Au nanoclusters (GSH–Ag/AuNCs) were prepared by the one-step ultraviolet radiation combined with microwave heating method. The effects of the molar ratio of Au–Ag and different types of energy suppliers on the fluorescent performance of GSH–Ag/AuNCs were studied in detail. After that, a new ratio fluorescent probe (RF-probe) based on the mixing of GSH–Ag/AuNCs with carbon dots (CDs) was designed for sensitive and selective determination of copper gluconate (CG) and cupric sulfate (CS). For the CDs–GSH–Ag/AuNCs RF-probe, the fluorescence (FL) of CDs (at 440[Formula: see text]nm) and that of alloy nanoclusters (NCs) (at 605[Formula: see text]nm) were, respectively, unaffected and strongly quenched in the presence of CG/CS at [Formula: see text][Formula: see text]nm coming from the dynamic quenching process. Corresponding linear ranges and limit of detection (LOD) of the RF-probe for the CG/CS assay were estimated to be 0.17–6.20/0.17–5.62[Formula: see text][Formula: see text]mol/L and 16.80/15.95[Formula: see text]nmol/L, respectively. Furthermore, the proposed RF-probe was successfully used for the assays of CG in CG tablets and CG additive, and CS in infant formula and CS additive, respectively.

scholarly journals Disposable stencil-printed carbon electrodes for electrochemical analysis of sildenafil citrate in commercial and adulterated tablets

2021 ◽  
Author(s):  
Danielly Rocha ◽  
Habdias Silva-Neto ◽  
Laísa Oliveira ◽  
Shellyda Souza ◽  
Mário Santana ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Graphite Powder ◽  
Electrochemical Analysis ◽  
Sildenafil Citrate ◽  
Carbon Electrodes ◽  
Heterogeneous Electron Transfer ◽  
Linear Behavior ◽  
Electron Transfer Rate Constant ◽  
3D Printed

Forensic studies are extremally important to investigate suspected adulterations of consumable products, such as Viagra®. This report describes the determination of sildenafil citrate (SC) in commercial and adulterated tablets based on square-wave voltammetry (SWV) measurements using disposable stencil-printed carbon electrodes. The conductive ink used for the manufacture of integrated electrodes was produced by combining graphite powder and glass varnish. To promote a reusable strategy for limiting the geometric area of the electrodes, a 3D-printed holder was constructed. Detailed morphological and electrochemical characterization studies revealed well-defined graphite flakes incorporated on the polymeric substrate and a faster heterogeneous electron-transfer rate constant (Ks = 1.3 × 10–3 cm s–1). Based on the analytical performance, a linear behavior was observed in a SC concentration range from 1 to 20 µmol L–1 with limit of detection equal to 0.2 µmol L–1. The selectivity of the proposed method was evaluated and the presence of potentially interfering compounds like phosphate, lactose, paracetamol and tadalafil and no difference higher than 15% was observed. The analysis of SC was performed in commercial and seized tablets and the achieved values were 50 ± 1 mg for Viagra® tablet, 54 ± 1 mg for generic formulations 38 ± 1 mg for seized tablet. In addition, the proposed method offered satisfactory accuracy (98.2 – 102.0%) no noticeable matrix effect. Lastly, considering the achieved results, the use of stencil-printed carbon electrodes and SWV has demonstrated to be a powerful and robust analytical tool for forensic investigations.

scholarly journals Experimental and computational evaluation of kolliphor RH 40 as a new fluorescence enhancer in development of a micellar-based spectrofluorimetric method for determination of lapatinib in tablets and urine

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0239918
Author(s):  
Hany W. Darwish ◽  
Ahmed H. Bakheit ◽  
Nasser S. Al-shakliah ◽  
A. F. M. Motiur Rahman ◽  
Ibrahim A. Darwish
Keyword(s):  
Kinase Inhibitor ◽  
Ph Value ◽  
Limit Of Detection ◽  
Accurate Determination ◽  
Content Uniformity ◽  
Pharmaceutical Tablets ◽  
Computational Evaluation ◽  
Green Approach ◽  
Spectrofluorimetric Method

This study describes, for the first time, the experimental and computational investigations for evaluation of kolliphor RH 40 as a fluorescence enhancer surfactant in development of a spectrofluorimetric method for determination of lapatinib (LAP), a tyrosine kinase-inhibitor drug approved for targeted therapy of breast cancer. The investigations involved the ability of kolliphor RH 40 to form micelles with LAP and its enhancing effect on the weak native fluorescence of LAP at 420 nm after its excitation at 292 nm. Different variables were experimentally investigated: types of organized media, diluting solvent, buffer type and its pH value. The optimum values of the most influencing variables on the interaction of kolliphor RH 40 with LAP were refined by the computational response surface methodology (RSM). Under the optimized conditions, it was found that kolliphor RH 40 forms micelles with LAP, and its fluorescence enhancing ability was higher than other surfactants tested by ~ 10-folds. This micellar-enhanced effect of kolliphor RH 40 was employed in the development of a new sensitive spectrofluorimetric method for the accurate determination of LAP. The method was validated according to the guidelines of the International Conference on Harmonization (ICH) for validation of analytical procedures. The relative fluorescence intensity (RFI) was in excellent linear relationship (correlation coefficient was 0.998) with the LAP concentrations in the range of 50–1000 ng/mL. The method limit of detection (LOD) was 27.31 ng/mL and its accuracy was ≥ 99.82%. The method was successfully applied to the determination of LAP in its pharmaceutical tablets, tablets dissolution testing and content uniformity. The method application was extended to the determination of LAP in urine samples with an accuracy of 99.82 ± 3.45%. The method is considered as an eco-friendly green approach and more efficient alternative method to the existing analytical methodologies for determination of LAP.

scholarly journals A simple HPLC method containing greener modifier and slighter temperature elevated for simultaneous determination of three statin drugs in tablets

2021 ◽  
Author(s):  
Wael Alshitari ◽  
Fatimah Al-Shehri ◽  
Deia Abd El-Hady ◽  
Hassan M. Albishri
Keyword(s):  
Limit Of Detection ◽  
Hplc Method ◽  
Optimal Conditions ◽  
Limit Of Quantification ◽  
Column Temperature ◽  
Pharmaceutical Tablets ◽  
Rp Hplc ◽  
Ich Guidelines ◽  
Statin Drugs

AbstractStatins drugs are thought to be among the most prescribed drugs worldwide for the treatment of hypercholesterolaemia. A simple and reliable RP-HPLC method has been successfully employed for simultaneously separating and qualifying three statin drugs including atorvastatin, rosuvastatin and simvastatin in pharmaceutical tablets. The optimal conditions were mobile phase 50:50 (v/v) (formic acid pH 2.50: ETOH), column temperature 40.00 °C, detection wavelength 238.00 nm, and flow rate 1.00 mL/min. The proposed method has been validated based on the ICH guidelines in terms of linearity, precision, accuracy, and limit of detection and limit of quantification. The linear range investigated 2.0–80.0, 4.0–100.00, and 12.00–120.00 µg/mL for rosuvastatin, atorvastatin and simvastatin respectively with coefficients of determination (R2) within the range of 0.9993–0.9995. The LOD and LOQ for rosuvastatin, atorvastatin and simvastatin were (1.57, 4.76 µg/mL), (1.87, 5.66 µg/mL), (3.46, 10.49 µg/mL) respectively. In addition, in order to evaluate the feasibility of the method developed, it was employed towards the quantification of the pharmaceutical tablets for the analytes investigated and excellent recovery was obtained.

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