scholarly journals Glazing effect for producing environmentally friendly ceramics for cladding applications

2021 ◽  
pp. 16-16
Author(s):  
Emilija Kostic ◽  
Maja Vujovic ◽  
Biljana Milosavljevic
Keyword(s):  
Biological Samples ◽  
Limit Of Detection ◽  
Forensic Toxicology ◽  
Pharmaceutical Preparations ◽  
Cost Effective ◽  
Alcoholic Beverages ◽  
Chromatography Method ◽  
Calibration Dependence ◽  
Ethanol Determination

A simple, cost-effective and fast headspace gas chromatography method coupled with flame ionization detection (HS-GC/FID) for determination of ethanol was developed and validated for clinical and forensic toxicology purposes. HS-GC/FID is often used for alcohol determination in different biological and non-biological samples. The calibration dependence of the method was linear in the range from 0.15 to 4.00 g dm-3 (r2=0.999) with adequate accuracy (99-106 %) and precision. The limit of detection (LOD) was 0.006 g dm-3. The method was quantitative (LOQ) above 0.020 g dm-3. The new method was successfully used for determination of ethanol in biological samples of intoxicated patients, car accidents participants, participants in criminal acts, and postmortem samples, non-biological samples such as alcoholic beverages, alcohol-based herbal preparations, cosmetic preparations, etc. This method is easy to perform, making it suitable not only for the routine applications in clinical biochemistry and forensic laboratories, but also in different fields of industry (e.g. for pharmaceutical preparations, cosmetics, dietary supplements, etc.). Some of the applications for ethanol determination in different samples related to various clinical-forensic cases are presented.

Optimum HPLC Conditions for Determination of Dibucaine HCL, Fluocortolone Pivalate and Fluocortolone Caproate by Using Experimental Design

2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç
Keyword(s):  
Experimental Design ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Acid Mixture ◽  
Solution Stability ◽  
Uv Detector

Introduction:This paper presents the development and validation of a novel, fast, sensitive and accurate high performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical preparations.Experiment:Development of the chromatographic method was based on an experimental design approach. A five-level-three-factor central composite design requiring 20 experiments in this optimization study was performed in order to evaluate the effects of three independent variances including mobile phase ratio, flow rate and amount of acid in the mobile phase.Conclusion:The optimum composition for mobile phase was found as a methanol:water:acetic acid mixture at 71.6 : 26.4 : 2 (v/v/v) ratio and optimum separation was acquired by isocratic elution with a flow rate of 1.3 mL/min. The analytes were detected using a UV detector at 240 nm. The developed method was validated in terms of linearity, precision, accuracy, limit of detection/quantitation and solution stability and successfully applied to the determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical topical formulations such as suppositories and ointments.

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 Immobilization-Free Electrochemical Sensor Coupled with a Graphene-Oxide-Based Aptasensor for Glycated Albumin Detection

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 85
Author(s):  
Wassa Waiwinya ◽  
Thitirat Putnin ◽  
Dechnarong Pimalai ◽  
Wireeya Chawjiraphan ◽  
Nuankanya Sathirapongsasuti ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Detection Method ◽  
Limit Of Detection ◽  
Glycated Albumin ◽  
Cost Effective ◽  
Logarithmic Scale ◽  
Electrochemical Aptasensor ◽  
Alternative Approach

An immobilization-free electrochemical sensor coupled with a graphene oxide (GO)-based aptasensor was developed for glycated human serum albumin (GHSA) detection. The concentration of GHSA was monitored by measuring the electrochemical response of free GO and aptamer-bound GO in the presence of glycated albumin; their currents served as the analytical signals. The electrochemical aptasensor exhibited good performance with a base-10 logarithmic scale. The calibration curve was achieved in the range of 0.01–50 µg/mL. The limit of detection (LOD) was 8.70 ng/mL. The developed method was considered a one-drop measurement process because a fabrication step and the probe-immobilization process were not required. This simple sensor offers a cost-effective, rapid, and sensitive detection method, and could be an alternative approach for determination of GHSA levels.

scholarly journals DETERMINATION OF 10-GINGEROL IN INDIAN GINGER BY VALIDATED HPTLC METHOD OF SAMPLES COLLECTED ACROSS SUBCONTINENT OF INDIA

2016 ◽  
Vol 8 (12) ◽  
pp. 190
Author(s):  
Kamran Ashraf ◽  
Syed Adnan Ali Shah ◽  
Mohd Mujeeb
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Aluminum Plates ◽  
Layer Chromatography ◽  
Hptlc Method

<p><strong>Objective: </strong>A simple, sensitive, precise, and accurate stability indicating HPTLC (high-performance thin-layer chromatography) method for analysis of 10-gingerol in ginger has been developed and validated as perICH guidelines.</p><p><strong>Methods: </strong>The separation was achieved on TLC (thin layer chromatography) aluminum plates pre-coated with silica gel 60F<sub>254</sub> using n-hexane: ethyl acetate 55:45 (%, v/v) as a mobile phase. Densitometric analysis was performed at 569 nm.</p><p><strong>Results: </strong>This system was found to have a compact spot of 10-gingerol at <em>R</em><sub>F</sub> value of 0.57±0.03. For the proposed procedure, linearity (<em>r</em><sup>2</sup> = 0.998±0.02), limit of detection (18ng/spot), limit of quantification (42 ng/spot), recovery (ranging from 98.35%–100.68%), were found to be satisfactory.</p><p><strong>Conclusion: </strong>Statistical analysis reveals that the content of 10-gingerol in different geographical region varied significantly. The highest and lowest concentration of 10-gingerol in ginger was found to be present in a sample of Patna, Lucknow and Surat respectively which inferred that the variety of ginger found in Patna, Lucknow are much superior to other regions of India.</p>

scholarly journals Spectrophotometric Determination of Zidovudine in Pharmaceuticals Based on Charge-Transfer Complexation Involving N-Bromosuccinimide, Metol and Sulphanilic Acid as Reagents

2007 ◽  
Vol 4 (2) ◽  
pp. 173-179 ◽  
Author(s):  
K. Basavaiah ◽  
U. R. Anil Kumar
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Sulphanilic Acid ◽  
Bulk Drug ◽  
Student’S T ◽  
Charge Transfer Complexation

A simple spectrophotometric method is proposed for the determination of zidovudine(ZDV) in bulk drug and in pharmaceutical preparations. The method is based on the oxidation of ZDV by a known excess of oxidant N-bromosuccinimide (NBS), in buffer medium of pH 1.5, followed by the estimation of unreacted amount of oxidant with metol and sulphanilic acid. The reacted oxidant corresponds to the amount ZDV. The purple-red reaction product absorbs maximally at 530 nm and Beer’s law is obeyed over a range 5 to 75 μg mL-1. The apparent molar absorptivity is calculated to be 5.1×103L mol-1cm-1, and the corresponding Sandell sensitivity value is 0.052 μg cm-2. The limit of detection and quantification are found to be 0.90 and 2.72, respectively. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The method was successfully applied to the assay of ZDV in tablet/capsule preparations and the results were statistically compared with those of the reference method by applying the Student’s t-test and F-test. No interference was observed from the common tablet/capsule excipients. The accuracy of the method was further ascertained by performing recovery studies via standard-addition method.

scholarly journals Determination of Sodium Cromoglycate by a New Kinetic Spectrophotometric Method in Biological Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Mohsen Keyvanfard ◽  
Khadijeh Alizad ◽  
Razieh Shakeri
Keyword(s):  
Standard Deviation ◽  
Sodium Cromoglycate ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Biological Samples ◽  
Limit Of Detection ◽  
Micellar Medium ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A new kinetic spectrophotometric method is described for the determination of ultratrace amounts of sodium cromoglycate (SCG). The method based on catalytic action of SCG on the oxidation of amaranth with periodate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of the amaranth at 518 nm, for the first 4 min from initiation of the reaction. Calibration curve was linear in the range of 4.0−36.0 ng mL−1SCG. The limit of detection is 2.7 ng mL−1SCG. The relative standard deviation (RSD) for ten replicate analyses of 12, 20, and 28 ng mL−1SCG was 0.40%, 0.32%, and 0.53%, respectively. The proposed method was used for the determination of SCG in biological samples.

scholarly journals Oxytetracycline Residues in Honey Analyzed by Liquid Chromatography with UV Detection

2013 ◽  
Vol 57 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Anna Gajda ◽  
Andrzej Posyniak ◽  
Andrzej Bober ◽  
Tomasz Błądek ◽  
Jan Żmudzki
Keyword(s):  
Liquid Chromatography ◽  
Oxalic Acid ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Experimental Treatment ◽  
Uv Detection ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Liquid Chromatography Method

Summary A liquid chromatography method with UV detection for determination of oxytetracycline (OTC) in honey has been developed. The samples were extracted with the solution of oxalic acid. The clean-up procedure was performed by solid phase extraction (SPE) using polymeric Strata X and carboxylic acid cartridges. Chromatographic separation was carried out on the Luna C8 analytical column with mobile phase consisting of acetonitrile-0.02 M oxalic acid. The method has been successfully validated according to the requirements of the European Decision 2002/657/EC and this method is used in routine control of oxytetracycline in honey samples. The limit of detection (LOD) and limit of quantification (LOQ) of the presented method were 10 and 12.5 μg/kg, respectively. The developed method has also been verified in quantitative determination of oxytetracycline residues in honey after experimental treatment with this product in bee colonies.

scholarly journals Spectrophotometric determination of Phenylephrine hydrochloride and Salbutamol sulphate drugs in pharmaceutical preparations using diazotized Metoclopramide hydrochloride

2015 ◽  
Vol 12 (1) ◽  
pp. 167-177 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Correlation Coefficients ◽  
Limit Of Quantification ◽  
Pharmaceutical Dosage Forms ◽  
Salbutamol Sulphate ◽  
Phenylephrine Hydrochloride ◽  
Relative Standard ◽  
Metoclopramide Hydrochloride

A spectrophotometric method has been proposed for the determination of two drugs containing phenol group [phenylephrine hydrochloride (PHP) and salbutamol sulphate (SLB)] in pharmaceutical dosage forms. The method is based on the diazotization reaction of metoclopramide hydrochloride (MCP) and coupling of the diazotized reagent with drugs in alkaline medium to give intense orange colored product (?max at 470 nm for each of PHP and SLB). Variable parameters such as temperature, reaction time and concentration of the reactants have been analyzed and optimized. Under the proposed optimum condition, Beer’s law was obeyed in the concentration range of 1-32 and 1-14 ?g mL-1 for PHP and SLB, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for each of PHP and SLB were 0.60, 0.52 ?g mL-1 and 2.02, 1.72 ?g mL-1, respectively. No interference was observed from common excipients present in pharmaceutical preparations. The good correlation coefficients and low relative standard deviation assert the applicability of this method. The suggested method was further applied for the determinations of drugs in commercial pharmaceutical preparations, which was compared statistically with reference methods by means of t- test and F- test and were found not to differ significantly at 95% confidence level. The procedure was characterized by its simplicity with accuracy and precision.

scholarly journals DEVELOPMENT AND VALIDATION OF STABILITY INDICATING HPTLC METHOD FOR DETERMINATION OF APIXABAN AS BULK DRUG

2019 ◽  
pp. 37-42
Author(s):  
Mrinalini C. Damle ◽  
Swapnil S Waghmare ◽  
PURUSHOTAM SINHA
Keyword(s):  
Thin Layer ◽  
High Performance ◽  
Limit Of Detection ◽  
Chromatography Method ◽  
Stability Indicating ◽  
Chromatographic Condition ◽  
Bulk Drug ◽  
Development And Validation ◽  
Hptlc Method

Objective: To develop and validate simple, sensitive stability indicating HPTLC (High performance thin layer chromatography) method for apixaban. Methods: The chromatographic separation was performed on aluminium plates precoated with silica gel 60 F254 using toluene: ethyl acetate: methanol (3:6:1 v/v/v) as mobile phase followed by densitometric scanning at 279 nm. Results: The chromatographic condition shows sharp peak of apixaban at Rf value of 0.38±0.03. Stress testing was carried out according to international conference on harmonization (ICH)Q1A (R2) guidelines and the method was validated as per ICH Q2(R1) guidelines. The calibration curve was found to be linear in the concentration range of 100-500 ng/band for apixaban. The limit of detection and quantification was found to be 11.66ng/bandand35.33ng/band, respectively. Conclusion: A new simple, sensitive, stability indicating high performance thin layer chromatographic (HPTLC) method has been developed and validated for the determination of apixaban.

Determination of Mimosine and 2,3-Dihydroxypyridine in Leucaena leucocephala by Reversed Phase High-Performance Liquid Chromatography

2011 ◽  
Vol 140 ◽  
pp. 296-301 ◽  
Author(s):  
Cai Mei Wu ◽  
Hong Min Yuan ◽  
Gang Jia ◽  
Zhi Sheng Wang ◽  
Xiu Qun Wu
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Leucaena Leucocephala ◽  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Quantitative Detection ◽  
Uv Detector ◽  
Chromatography Method

A reversed high performance liquid chromatography method was developed for the quantitative determination of mimosine and 2,3-DHP in leaves ofLeucaena Leucocephala. Mimosine and 2,3DHP were extracted using 0.1N HCl.The chromatograph conditions were investigated and optimized. The optimal HPLC conditions as follows: Agilent HC-C18 column （4.6×150mm,5μm） was used at 30°C. The method used a variable wavelength UV detector at 280nm, the mobile phase consisted of 0.2 % (w/v) orthophosphoric acid and methanol, the gradient elution was adopted. The injection volume was 10μL. The linearity is favorable in the range of 1.0 to 50μg mL-1with a correlation coefficient of 0.99998 for mimosine and 0.99902 for 2,3DHP. Under the optimal conditions, the method limit of detection (LOD) of mimosine and 2,3DHP were 0.40mg/kg and 0.55mg/kg respectively. The recovery of mimosine was 87.00-94.70% with the RSD (n=5) of 2.75-3.81% in the spiked levels 0,1, 5, 20mg/g. At the same time, the recovery of 2,3DHP was 88-95.4% with the RSD (n=5) of 2.24-4.90%. The method was found to be simple, sensitive, fast and accurate, and has been applied successfully for the quantitative detection of mimosine and 2,3-DHP in leaves ofLeucaena Leucocephala, plasma and excretion of ruminant.

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