Determination of Sulpiride by Capillary Electrophoresis with End-Column Electrogenerated Chemiluminescence Detection

Abstract Background: Capillary electrophoresis (CE) with tris(2,2′-bipyridyl)ruthenium(II) [Ru(bpy)32+]-electrogenerated chemiluminescence (ECL) detection is a promising method for clinical analysis. In this study, a method combining CE with Ru(bpy)32+ ECL (CE-ECL) detection that can be applied to amine-containing clinical species was developed, and the performance of CE-ECL as a quantitative method for determination of sulpiride in human plasma or urine was evaluated. Methods: Sulpiride was separated by capillary zone electrophoresis in uncoated fused-silica capillaries [50 cm × 25 μm (i.d.)] filled with phosphate buffer (pH 8.0) and a driving voltage of +15 kV, with end-column Ru(bpy)32+ ECL detection. A platinum disc electrode was used as working electrode. Sulpiride in human plasma or urine samples (100 μL) was extracted by a double-step liquid-liquid extraction procedure, dried under nitrogen at 35 °C in a water bath, and reconstituted with 100 μL of filtered water. The extraction solvent was ethyl acetate–dichloromethane (5:1 by volume). Results: Under optimum conditions (pH 8.0 phosphate buffer, injection for 6 s at 10 kV, and +1.2 V as detection potential), separation of sulpiride was accomplished within 4 min. The calibration curve was linear over a concentration range of 0.05–25.0 μmol/L, and the limit of detection was 2.9 × 10−8 mol/L for sulpiride. Intra- and interday CVs for ECL intensities were <6%. Extraction recoveries of sulpiride were 95.6–101% with CVs of 2.9–6.0%. The method was clinically validated for patient plasma and urine samples. Conclusions: CE combined with Ru(bpy)32+ ECL is reproducible, precise, selective, and enables the analysis of sulpiride in human plasma and urine. It thus is of value for rapid and efficient analysis of amine-containing analytes of clinical interest.

Download Full-text

Capillary Electrophoresis Method for Determination of Escitalopram Oxalate in Urine Samples and Different Dosage Forms

Journal of Chromatographic Science ◽

10.1093/chromsci/bmaa036 ◽

2020 ◽

Vol 58 (8) ◽

pp. 759-769

Author(s):

Wafa F S Badulla ◽

Arın G Dal Poçan ◽

Zeki Atkoşar ◽

Göksel Arlı

Keyword(s):

Capillary Electrophoresis ◽

Limit Of Detection ◽

Background Electrolyte ◽

Dosage Forms ◽

Fused Silica ◽

Urine Samples ◽

Effective Length ◽

Simple Liquid ◽

Pharmaceutical Dosage Forms

Abstract Application of capillary electrophoresis (CE) has become a rapidly growing analytical technique for the estimation of drugs in pharmaceutical dosage forms and biological fluids. In this study, an effective and sensitive method was developed for the determination of escitalopram oxalate (ESC-OX) by CE with diode-array detection at 200 nm. The separation was achieved by a fused silica capillary with 40 cm effective length (48.5 cm total, 75 μm i.d.). The background electrolyte was composed of 15 mM phosphate buffer (pH 2.5). The applied potential was 22.5 kV, and the samples were injected at 50 mbar pressure for 10 s. Metoprolol was used as an internal standard (IS). The migration time under these optimum conditions was 6.51 ± 0.07 and 6.73 ± 0.08 min for ESC-OX and IS, respectively, with total run time 7 min. The method was validated for linearity, precision, accuracy, specificity and sensitivity. The limit of detection was calculated as 3.85 and 5.07 ng mL−1 for standard and urine samples, respectively. The developed method was employed successfully for the determination of ESC-OX in different pharmaceutical dosage forms and spiked human urine after simple liquid–liquid extraction with good recovery.

Download Full-text

Quantification of Riboflavin, Flavin Mononucleotide, and Flavin Adenine Dinucleotide in Human Plasma by Capillary Electrophoresis and Laser-induced Fluorescence Detection

Clinical Chemistry ◽

10.1093/clinchem/45.6.862 ◽

1999 ◽

Vol 45 (6) ◽

pp. 862-868 ◽

Cited By ~ 58

Author(s):

Steinar Hustad ◽

Per Magne Ueland ◽

Jørn Schneede

Keyword(s):

Capillary Electrophoresis ◽

Human Plasma ◽

Fluorescence Detection ◽

Limit Of Detection ◽

Sodium Dodecyl ◽

Laser Induced Fluorescence ◽

Fused Silica ◽

Flavin Mononucleotide ◽

Laser Induced Fluorescence Detection

Abstract Background: Riboflavin is the precursor of flavin mononucleotide (FMN) and FAD, which serve as cofactors for several redox enzymes. We have developed a capillary electrophoresis method for the determination of riboflavin and its two coenzyme forms in human plasma. Methods: Trichloroacetic acid-treated plasma was subjected to solid-phase extraction on reversed-phase columns. The analytes were separated by micellar electrokinetic capillary chromatography in uncoated fused- silica capillaries filled with borate buffer containing 50 mmol/L sodium dodecyl sulfate, methanol, and N-methylformamide. Native fluorescence was monitored at 530 nm, using an argon laser operating at 488 nm as excitation source. Results: The assay was linear over a concentration range of two orders of magnitude, and the limit of detection was far below physiological concentrations for all vitamers. The within-day and between-day coefficients of variation were 4–9% and 6–12%, respectively. The reference values (median, 5–95 percentiles) obtained by analyzing plasma from 63 healthy subjects were 8.6 nmol/L (2.7–42.5 nmol/L) for riboflavin, 7.0 nmol/L (3.5–13.3 nmol/L) for FMN, and 57.9 nmol/L (44.5–78.1 nmol/L) for FAD. Conclusions: Capillary electrophoresis with laser-induced fluorescence detection allows determination of all riboflavin vitamers far below physiological concentrations. The method may become a useful tool for the assessment of riboflavin status in humans.

Download Full-text

Development and ICH Validation of a RP-HPLC-UV Method for the Quantification of Thimerosal in Topic Creams

Journal of the Mexican Chemical Society ◽

10.29356/jmcs.v60i4.110 ◽

2017 ◽

Vol 60 (4) ◽

Author(s):

Guadalupe Pérez-Caballero ◽

Nancy Muro-Hidalgo ◽

Elvia Adriana Morales-Hipólito ◽

Alma Villaseñor ◽

Raquel López-Arellano

Keyword(s):

Phosphate Buffer ◽

Limit Of Detection ◽

Extraction Procedure ◽

Reversed Phase ◽

Sample Treatment ◽

Limit Of Quantification ◽

Rp Hplc ◽

Validation Parameters ◽

Quality Control Tool

A reversed phase high-performance liquid chromatography (RP-HPLC) method for determination of Thimerosal (TMS) in topical creams was optimized and validated according to the ICH guidelines which include accuracy, precision, selectivity, robustness, limit of detection (LOD), limit of quantification (LOQ), linearity and range. For topical creams, sample treatment is often an overwhelming step essentially due to its oily nature. For the first time a simple and robust extraction procedure for TMS using phosphate buffer (pH 5.5, 0.2M) was successfully developed. This method describes the TMS quantitation by HPLC in a topical product containing 0.01% fluocinolone acetonide (FLA) as the active molecule. The HPLC separation was achieved on a Column Symmetry® and a methanol: phosphate buffer (pH 2.5, 0.05M) 70:30 v/v mobile phase and wavelength 218 nm. Results from both standards and samples showed adequate validation parameters. Noteworthy, linearity was within the range 1.2 - 2.8 μg/mL. Additionally, robustness and TMS stability were established after sample extraction. The method provides an efficient and safe quality control tool for determination of TMS in topical creams.

Download Full-text

Development of a HPLC-UV method for determination of meloxicam in human plasma and pharmaceutical dosage forms

Acta Medica Marisiensis ◽

10.2478/amma-2014-0031 ◽

2014 ◽

Vol 60 (4) ◽

pp. 142-145 ◽

Cited By ~ 2

Author(s):

Csifo Enikő ◽

Croitoru M. D. ◽

Fülöp Ibolya ◽

Muntean Daniela-Lucia

Keyword(s):

Human Plasma ◽

Limit Of Detection ◽

Low Cost ◽

Extraction Procedure ◽

Dosage Forms ◽

Composition Gradient ◽

Range Limit ◽

Limit Of Quantification ◽

Pharmaceutical Dosage Forms

Abstract Objectives: A simple, quick and low cost HPLC-UV method for assay of meloxicam in plasma and pharmaceutical dosage forms was developed. Methods: Separation and assay of meloxicam, using a simple reverse phase HPLC-UV method was achieved using an Agilent Zorbax SB C18 column, with methanol and 1% aqueous solution of glacial acetic acid as mobile phase. Elution was performed with composition gradient, meloxicam being detected at 355 nm with a 5 minutes analysis time. The method was tested on human plasma and pharmaceutical dosage forms. Results: The retention time of the meloxicam was 3,7 minutes. Regression analysis showed good linearity, with correlation coefficient R= 0,9997; linear regression equation: y = 206,1x -77,5 over the 20-2000 ng/ml concentration range. Limit of detection was determined to be 5 ng/ml and limit of quantification was set at 15 ng/ml. The recovery of the analyte in human plasma was low: 30,50%, however it was reproducible, with a coefficient of variation of 4,83%. The analysis of the tablets resulted in a 85,82% of meloxicam compared to the declared concentration. Conclusions: The method proposed is quick, simple and adequate for detecting the meloxicam in human plasma. Although the recovery rate was low, it was reproducible, which leads to the fact, that improving extraction procedure can optimize the method.

Download Full-text

Determination of Urinary Pterins by Capillary Electrophoresis Coupled with LED-Induced Fluorescence Detector

Molecules ◽

10.3390/molecules24061166 ◽

2019 ◽

Vol 24 (6) ◽

pp. 1166 ◽

Cited By ~ 2

Author(s):

Wojciech Grochocki ◽

Magdalena Buszewska-Forajta ◽

Szymon Macioszek ◽

Michał J. Markuszewski

Keyword(s):

Capillary Electrophoresis ◽

Limit Of Detection ◽

Urine Samples ◽

High Price ◽

Range Limit ◽

Uv Detector ◽

Fluorescence Detector ◽

Limit Of Quantification ◽

Sample Stability

Urinary pterins have been found as potential biomarkers in many pathophysiological conditions including inflammation, viral infections, and cancer. However, pterins determination in biological samples is difficult due to their degradation under exposure to air, light, and heat. Besides, they occur at shallow concentration levels, and thus, standard UV detectors cannot be used without additional sample preconcentration. On the other hand, ultra-sensitive laser-induced fluorescence (LIF) detection can be used since pterins exhibit native fluorescence. The main factor that limits an everyday use of LIF detectors is its high price. Here, an alternative detector, i.e., light-emitted diode induced fluorescence (LEDIF) detector, was evaluated for the determination of pterins in urine samples after capillary electrophoresis (CE) separation. An optimized method was validated in terms of linearity range, limit of detection (LOD), limit of quantification (LOQ), intra- and interday precision and accuracy, sample stability in the autosampler, and sample stability during the freezing/thawing cycle. The obtained LOD (0.1 µM) and LOQ (0.3 µM) values were three-order of magnitude lower compared to UV detector, and two orders of magnitude higher compared to previously reported house-built LIF detector. The applicability of the validated method was demonstrated in the analysis of urine samples from healthy individuals and cancer patients.

Download Full-text

Determination of Branched-Chain Amino Acids in Food Supplements and Human Plasma by a CE-MS/MS Method with Enhanced Resolution

International Journal of Molecular Sciences ◽

10.3390/ijms22158261 ◽

2021 ◽

Vol 22 (15) ◽

pp. 8261

Author(s):

Juraj Piestansky ◽

Michaela Matuskova ◽

Ivana Cizmarova ◽

Dominika Olesova ◽

Peter Mikus

Keyword(s):

Amino Acids ◽

Human Plasma ◽

Limit Of Detection ◽

Background Electrolyte ◽

Branched Chain Amino Acids ◽

Fused Silica ◽

Suitable Alternative ◽

Enhanced Resolution ◽

Validation Parameters ◽

Branched Chain

In the presented study, a capillary electrophoresis-mass spectrometry method combining high separation efficiency and sensitive detection has been developed and validated, for the first time, to quantify branched chain amino acids (valine, isoleucine, leucine) in commercial food and sport supplement samples and human plasma samples. The separations were performed in a bare fused silica capillary. The background electrolyte was composed of 500 mM formic acid with pH 2.0. The plasma sample pretreatment was realized by simple protein precipitation with acetonitrile. Injection of a short zone of highly basic electrolyte before the sample injection and application of the negative pressure on the separation were accompanied by enhanced resolution of the isobaric amino acids—isoleucine and leucine. The developed method was characterized by favorable validation parameters, such as linearity (r2 > 0.99), accuracy and precision, the limit of detection, lower limit of quantification, or robustness. These parameters were more than sufficient for the quantification of branched chain amino acids in various samples. The determined concentrations of branched chain amino acids in food and sports supplements were in very good agreement with the content declared by the manufacturer. The investigated concentrations of branched chain amino acids were in the range 294.68–359.24 µM for valine, 91.76–95.67 µM for isoleucine, and 196.78–251.24 µM for leucine. These concentrations fall within the physiological limits. The developed CE-MS/MS method represents a suitable alternative to traditional approaches used in branched chain amino acid quality control and bioanalysis.

Download Full-text