scholarly journals DETERMINATION OF CARBAMATE RESIDUES IN VEGATABLES, BULBS AND WATER

2020 ◽  
Vol 12 (9) ◽  
pp. 78-87
Author(s):  
Liem Van Nguyen ◽  
Dong Van Nguyen ◽  
Hien Thi To
Keyword(s):  
Fluorescence Detection ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Liquid Extraction ◽  
Fluorescent Compound ◽  
Phase Gradient ◽  
Liquid Liquid Extraction ◽  
Limit Of Quantitation

A method for the determination of residues of 10 carbamates including Aldicard Sulfoxide, Aldicarb sulfone, Oxamyl, Methomyl, 3-Hydroxycarbofuran, Aldicarb; Propoxur, Carbofuran, Carbaryl and Methiocarb in vegetables, bulbs and water was established based on High Performance Liquid Chromatography with fluorescence detection after derived post column. Solid samples were grinded in MeOH, clarify. Extraction liquid or water samples were cleaned by liquid-liquid extraction or SPE C18 Carbamates were extracted in HPLC C18 with mobile phase gradient MeOH/H2O and derived phthalaldehyde (OPA) and 2 - mercaptoethanol. A fluorescent compound 1 - hydroxytylthio - 2-metylisoindol was produced and detected by fluorescence detection with λex 340 nm and λem 445 nm. Limit of detection and limit of quantitation for the carbamates were 0.51 - 5.0 ppb and 1.69-9.09 ppb, respectively. The recoveries of the carbamates were from 73 to 95%. The concentrations of the carbamate in vegetables, bulbs and water at some investigated sites were low.

scholarly journals SENSITIVE DETERMINATION OF RELATED SUBSTANCES IN PIOGLITAZONE HYDROCHLORIDE BY HPLC

2017 ◽  
Vol 9 (2) ◽  
pp. 34
Author(s):  
N. Balaji ◽  
Sayeeda Sultana
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Internal Diameter ◽  
Related Substances ◽  
Relative Standard ◽  
Limit Of Quantitation

Objective: An efficient, high performance liquid chromatographic method has been developed and validated for the quantification of related substances in pioglitazone hydrochloride drug substance.Methods: This method includes the determination of three related substances in pioglitazone hydrochloride. The mobile phase A is 0.1% w/v triethylamine in water with pH 2.5 adjusted by dilute phosphoric acid. The mobile phase B is premixed and degassed mixtures of acetonitrile and methanol. The flow rate was 1 ml/min. The elution used was gradient mode. The HPLC column used for the analysis was symmetry C18 with a length of 250 mm, the internal diameter of 4.6 mm and particle size of 5.0 microns.Results: The developed method was found to be linear with the range of 0.006-250% with a coefficient of correlation 0.99. The precision study revealed that the percentage relative standard deviation was within the acceptable limit. The limit of detection and limit of quantitation of the impurities was less than 0.002%and 0.006% with respect to pioglitazone hydrochloride test concentration of 2000 µg/ml respectively. This method has been validated as per ICH guidelines Q2 (R1).Conclusion: A reliable, economical HPLC method was magnificently established for quantitative analysis of related substances of pioglitazone hydrochloride drug substance.

scholarly journals Development and validation of a SPE-UHPLC-fluorescence method for the analysis of ochratoxin-a in certain Turkish wines

2019 ◽  
Vol 38 (2) ◽  
pp. 161
Author(s):  
Elif Mine Oncu Kaya
Keyword(s):  
Ochratoxin A ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Internal Standard ◽  
Fluorescence Method ◽  
Limit Of Quantitation ◽  
Development And Validation

A sensitive Ultra-High Performance Liquid Chromatography (UHPLC)-fluorescence method was developed and validated for the determination of ochratoxin-A (OTA) in Turkish wine samples. Naphthalene was used as an internal standard in this study. OTA was separated on a C18 (3.0 mm × 100 mm × 1.8 µm) column and analyses were run under isocratic conditions, with a mobile phase consisting of water/acetonitrile/acetic acid (50:50:1, v/v/v). The flow rate and injection volume were 0.5 ml min−1 and 10 μl, respectively. The excitation and emission wavelengths were 330 nm and 460 nm for OTA, respectively, and 220 nm and 325 nm for internal standard, respectively. A solid-phase extraction (SPE) clean-up procedure on a C18 cartridge was used prior to the analysis of the wine samples by UHPLC. The developed method was validated with respect to linearity, precision, accuracy, limit of detection (LOD), limit of quantitation (LOQ), stability and robustness. The method presented good RSD (< 4 %) and recovery (102.6–105.2 %) values. The LOD and LOQ values were 0.01 ng ml–1 and 0.05 ng ml–1, respectively. All other parameters were acceptable. OTA amounts were found in the range of 2.72‒7.40 µg kg‒1 in the Turkish wine samples.

scholarly journals Development of a UHPLC-MS/MS method for the determination of quercetin in milk and its application to a pharmacokinetic study

2019 ◽  
Vol 63 (1) ◽  
pp. 87-91
Author(s):  
Małgorzata Gbylik-Sikorska ◽  
Anna Gajda ◽  
Artur Burmańczuk ◽  
Tomasz Grabowski ◽  
Andrzej Posyniak
Keyword(s):  
Formic Acid ◽  
Mobile Phase ◽  
High Performance ◽  
Therapeutic Agent ◽  
Clinical Mastitis ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Repeatability And Reproducibility ◽  
The Mean

Abstract Introduction: Quercetin is a polyphenolic flavonoid which has been used in traditional Chinese medicine as a natural therapeutic agent with a broad spectrum of activities (antioxidant, anticancer, neuroprotective, anti-inflammatory, antiviral and antibacterial). The aim of this study was to develop and validate a rapid and simple ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method for the determination of quercetin in milk. Material and Methods: Sample preparation was based on a liquid-liquid extraction with 0.5% formic acid in acetonitrile. The chromatographic separation was performed on a ZORBAX SB-C18 column with methanol and 0.5% formic acid as a mobile phase. Results: The procedure was successfully validated. The mean recovery of the analyte was 98%, with the corresponding intra- and inter-day variation less than 10% and 15%, respectively, and the repeatability and reproducibility were in the range of 3%–7.2% and 6.1%–12%, respectively. The lowest level of quantification was 1.0 μg/kg. Conclusion: The proposed method was successfully applied in evaluating the pharmacokinetics of quercetin in milk obtained from dairy cows with clinical mastitis after intramammary administration.

Sensitive and Fast Determination of Ceftiofur in Honey and Veterinary Formulation by HPLC-UV Method with Pre-column Derivatization

2020 ◽  
Vol 59 (1) ◽  
pp. 15-22
Author(s):  
Noha Rashed ◽  
Sahar Zayed ◽  
Fatma Fouad ◽  
Amany Abdelazeem
Keyword(s):  
Present Method ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Hplc Method ◽  
Fast Determination ◽  
Factors Affecting ◽  
Limit Of Quantitation ◽  
Derivatization Reaction

Abstract A novel, sensitive and rapid high performance liquid chromatography (HPLC) method for the determination of ceftiofur by pre-column derivatization with 1,2-naphthoquinone-4-sulfonate. Analysis was performed within 5 min on a Kinetex C18 column based on core-shell technology. The mobile phase composed of acetonitrile-water (50:50, v/v) pumped isocratically at a flow rate of 1.0 mL/min under UV detection at 254 nm. The factors affecting the derivatization reaction and separation conditions were carefully evaluated and optimized. The method was linear over the concentration range of 45–450 ng/mL with a limit of detection of 3.29 ng/mL and limit of quantitation of 10.97 ng/mL. The new method was successfully applied for the analysis of ceftiofur in the veterinary formulation and honey with average recoveries of 100.78% and 98. 83%, respectively. The present method is suitable and favorable for the analysis of ceftiofur on account of its sensitivity, rapidity and cost-effectiveness. In addition, it could have significant application for the determination of ceftiofur in other food products.

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.

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