scholarly journals Development of a Micellar Electrokinetic Chromatographic Method with Indirect UV Detection for Pregabalin Determination in Serum Samples

2018 ◽  
Vol 24 (4) ◽  
pp. 298-303
Author(s):  
Hamid Reza Sargazi ◽  
Elnaz Tamizi ◽  
Elaheh Rahimpour ◽  
Abolghasem Jouyban
Keyword(s):  
Limit Of Detection ◽  
Background Electrolyte ◽  
Fused Silica ◽  
Uv Detection ◽  
Aminosalicylic Acid ◽  
Serum Samples ◽  
Indirect Uv Detection ◽  
Limit Of Quantitation ◽  
Fused Silica Capillary

Background: A micellar electrokinetic chromatographic (MEKC)/ indirect UV detection method with hydrodynamic and electrokinetic injection has been developed for the determination of pregabalin in the serum samples. Methods: Separation of the drug was achieved on Agilent capillary electrophorese in less than 5 min using a 50 cm × 75 μm i.d. uncoated fused-silica capillary and a background electrolyte (BGE) consisting of 5-aminosalicylic acid (5-ASA, 10 mmol L-1), cetyl trimethylammonium bromide (CTAB, 1 mmol L-1) and tri-sodium citrate (4% w/v). The influence of various parameters on the separation such as separation voltage, injection time, cassette temperature, pH of BGE and organic modifier was investigated. Results: Method validation shown good linearity (R2> 0.999) in the range of 1.5-100 µg mL-1 of pregabalin. A limit of detection (LOD) of 0.8 μg mL-1 and a limit of quantitation (LOQ) of 2.6 μg mL-1 were reported for pregabalin. Conclusion: The proposed method was found to be suitable and accurate for the determination of pregabalin in serum samples.

scholarly journals Determination of flumazenil in serum by liquid chromatography-mass spectrometry: Application to kinetics study in acute diazepam overdose

2016 ◽  
Vol 73 (2) ◽  
pp. 146-151
Author(s):  
Snezana Djordjevic ◽  
Jasmina Jovic-Stosic ◽  
Vesna Kilibarda ◽  
Zoran Segrt ◽  
Natasa Perkovic-Vukcevic
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Half Life ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Serum Samples ◽  
Elimination Half Life ◽  
Elimination Half ◽  
Limit Of Quantitation

Backgound/Aim. Flumazenil is benzodiazepine receptor antagonist. It has been studied for a various indications, including reversal of sedation after surgery or diagnostic procedures, awakening of comatose patients in benzodiazepine overdose, or for symptomatic treatment of hepatic encephalopathy. Some drugs, like theophylline, may prolong its elimination half-life. Considering the long half-life of diazepam and its metabolites, concomitant use of theophylline may reduce the need for repeated dosing of flumazenil in patients with acute diazepam poisoning. The aim of this study was to introduce a reliable and accurate method for determining the concentration of flumazenil after therapeutic application in patients with acute poisoning, and using that method to assess whether the kinetics of flumazenil change in the presence of aminophylline (combination of theophylline and ethylenediamine in a 2 : 1 ratio) applied as concomitant therapy. Methods. Blood samples from patients with acute diazepam poisoning that received flumazenil at the dose of 0.5 mg, or the same dose with 3 mg/kg of body weight of aminophylline, were collected 1, 3, 10, 30, 60, 120 and 240 min after its intravenous administration. Samples were prepared by solid-phase extraction on Oasis HLB cartridges with ethylacetate as extracting agens. Flumazenil was determined by liquid chromatography with mass spectrometry (LC-MS) in single ion monitoring mode at m/z 304. Separation of flumazenil from matrix compound was performed on Lichrospher RP-8 column using the mixture of acidic acetonitrile and 20 mM of ammonium acetate in water (55 : 45) as a mobile phase. Results. The applied analitycal method showed excellent recovery (94.65%). The obtained extracts were much cleaner than the extracts obtained by the same extractant in the process of liquid-liquid extraction. The limit of detection of the LC-MS method described in this paper was 0.5 ng/mL and the limit of quantitation was 1 ng/mL. In the patients treated with both flumazenil and aminophylline, the elimination constant for flumazenil was significantly lower and the elimination half-life was longer (p < 0.05) in comparison with the same parameters in the patients who received flumazenil alone. Conclusion. The applied LC-MS method for the determination of flumazenil in serum samples of patients with acute diazepam poisoning is rapid, sensitive, precise and specific. Concomitant use with theophylline significantly prolonged elimination of flumazenil during the treatment of acute poisonings with diazepam.

scholarly journals Determination of N-methyl-2-pyrrolidone and its metabolites in urine by micellar electrokinetic chromatography

2011 ◽  
Vol 9 (5) ◽  
pp. 825-833 ◽  
Author(s):  
Jana Lokajová ◽  
Simo Porras ◽  
Eivor Elovaara ◽  
Susanne Wiedmer
Keyword(s):  
Solid Phase ◽  
Background Electrolyte ◽  
Sodium Dodecyl ◽  
Fused Silica ◽  
Rat Urine ◽  
Fused Silica Capillary ◽  
On Line ◽  
Electrokinetic Capillary Chromatography ◽  
Silica Capillary

AbstractA fast and accurate micellar electrokinetic capillary chromatography (MEKC) method was developed for monitoring N-methyl-2-pyrrolidone (NMP) exposure. Baseline separation of NMP and its main metabolites: 5-hydroxy-N-methyl-2-pyrrolidone (5HNMP), N-methylsuccinimide (MSI), 2-hydroxy-N-methylsuccinimide (2HMSI), and 2-pyrrolidone (2P) was obtained within 6 min in an uncoated fused silica capillary using 5 mM phosphate buffer and 140 mM sodium dodecyl sulfate (pH 7.1) as background electrolyte (BGE). On-line UV-detection was performed at 200 nm and the applied electric field was 400 V cm−1. Possible interference of BGE-induced system peaks on separation was investigated by computer simulation and no such interference was observed. The developed MEKC method combined with solid phase extraction for sample preparation was successfully applied to the analysis of urine of rats exposed to NMP. The urinary excretion was determined in 0–6 h and 6–24 h specimens collected after an intragastic administration of 308 mg NMP / kg rat body weight. The results of NMP disposition kinetics in rat urine are reported for NMP and metabolites.

scholarly journals Simultaneous determination of amlodipine and telmisartan from pharmaceutical products by way of capillary electrophoresis

2016 ◽  
Vol 29 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Adriana Modroiu ◽  
Gabriel Hancu ◽  
Robert Alexandru Vlad ◽  
Ștefana Stăcescu ◽  
Ruxandra Soare ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Applied Voltage ◽  
Limit Of Detection ◽  
Pharmaceutical Products ◽  
Fused Silica ◽  
Fixed Dose ◽  
Array Detector ◽  
System Temperature ◽  
Fused Silica Capillary

AbstractA rapid, simple and sensitive capillary zone electrophoresis method was developed for the simultaneous determination of amlodipine besylate and telmisartan, in fixed-dose combinations, through the utilization of a UV photodiode array detector. Electrophoretic parameters such as buffer concentration and pH, system temperature, applied voltage and injection parameters, were optimized in order to improve the efficiency of the separation. The best results were obtained when employing fused silica capillary (48 cm length X 50 μm ID) and 50 mM phosphate buffer electrolyte at pH 4.50, + 25 kV applied voltage, as well as 25°C system temperature. The separation was achieved in approximately 3 minutes, with a resolution of 4.90, while the order of migration was amlodipine followed by telmisartan. The analytical performance of the method was verified with regard to linearity, precision and robustness. In addition, the limit of detection and the quantification were calculated.

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

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.

A new method for the determination of ammonium in the vitreous humour based on capillary electrophoresis and its preliminary application in thanatochemistry

2019 ◽  
Vol 57 (4) ◽  
pp. 504-509 ◽  
Author(s):  
Rossella Gottardo ◽  
Covadonga Palacio ◽  
Kseniia M. Shestakova ◽  
Natalia E. Moskaleva ◽  
Federica Bortolotti ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Limit Of Detection ◽  
Forensic Analysis ◽  
Uv Detection ◽  
Vitreous Humour ◽  
Post Mortem ◽  
Indirect Uv Detection ◽  
Post Mortem Interval ◽  
Preliminary Application

Abstract Background Although the post-mortem increase of ammonium in biological fluids is well known, ammonium analysis in vitreous humour has never been used in recent times for the determination of the post-mortem interval. The present work represents a new application of capillary electrophoresis with indirect UV detection in the field of forensic analysis. Methods The electrophoretic separation was carried out in a running buffer made of 5 mM imidazole, 5 mM 18-crown-6 ether and 6 mM d,l-α-hydroxybutyric acid (HIBA). To overcome the lack of optical absorption of ammonium, indirect UV detection was applied. The used wavelength was 214 nm. Results The method showed good linearity in the concentration range from 0.16 to 5.0 mM. The limit of detection, 0.039 mmol/L, was established on the basis of the linearity curve. Precision and bias studies carried out on the pure ammonium solutions and in real biological samples, revealed %RSDs well below 20%. A preliminary application to real cases where the death time was precisely known (14 bodies) was carried out plotting vitreous humour ammonium vs. post-mortem interval with a resulting good linear correlation until 100 h post-mortem. Conclusions After validation in real cases, the present method can become a powerful tool to unravel one of the most challenging issues of forensic investigation: determination of the time of death.

scholarly journals Method Validation for Determination of Metformin Hydrochloride in Pharmaceutical Formulations by Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection

2019 ◽  
pp. 1-10
Author(s):  
Gazala Mohamed Ben-Hander ◽  
Ashraf Ahmed Ali Abdusalam ◽  
Bahruddin Saad ◽  
Ahmad Makahleh ◽  
Salizawati Muhamad Salhimi
Keyword(s):  
Capillary Electrophoresis ◽  
Background Electrolyte ◽  
Pharmaceutical Formulations ◽  
Fused Silica ◽  
Metformin Hydrochloride ◽  
Capacitively Coupled ◽  
Fused Silica Capillary ◽  
Normal Polarity ◽  
C 30

A method for the determination of metformin hydrochloride (MH) in pharmaceutical formulations by capillary electrophoresis with capacitively coupled contactless conductivity (C4D) detection was investigated. The separation was achieved under normal polarity mode at 17.5°C, 30 kV, hydrodynamic injection (50 mbar for 8 s) and using a bare fused silica capillary 72 cm × 75 µm i.d. (detection length, 10.5 cm from the outlet end of the capillary). The optimized background electrolyte consisted of 10 mM 2-morpholinoethanesulfonic acid and 10 mM histidine, pH 6.8. C4D parameters were set at fixed amplitude of 100 V and frequency of 650 kHz. Under the optimum conditions, the method shows good linearity over the range of 10-30 µg mL-1 MH (r2=0.9971). Limits of detection and quantitation based on S/N ratio of 3 and 10 were 0.049 and 0.15 µg mL-1, respectively. The proposed method was successfully applied to the assay of MH in pharmaceutical formulations and establishing the dissolution profiles for both immediate and extended release formulations of MH.

scholarly journals Evaluation of a capillary electrophoresis method for routine determination of varenicline tartrate in quality control laboratories

2015 ◽  
Vol 34 (2) ◽  
pp. 267 ◽  
Author(s):  
Mustafa Celebier ◽  
Engin Koçak ◽  
Sacide Altınöz
Keyword(s):  
Limit Of Detection ◽  
Background Electrolyte ◽  
Internal Standard ◽  
Fused Silica ◽  
Effective Length ◽  
Citrate Buffer ◽  
Hydrodynamic Mode ◽  
Ich Guidelines ◽  
Fused Silica Capillary ◽  
Electrophoresis Method

<p class="Body"><span lang="EN-US">In this study, analyses were carried out in a fused-silica capillary (i.d. 50.0 µm, total length 48.5 cm and effective length 40.0 cm), in normal mode, applying a voltage of 20 kV. Sample injections were made in a hydrodynamic mode over 7 seconds under a pressure of 50 mbar. Capillary temperature was set at 35 <sup>°</sup>C and the detection was performed at 205 nm wavelenght. Background electrolyte was </span><span lang="EN-US">40 mM citrate buffer at pH 6.0 and the internal standard was labetalol HCl. Total analysis time was shorter than 5 minutes. The method was validated according to the ICH guidelines and it was found to be linear, precise, accurate, specific, robust and rugged. Linearity range was found to be </span><span lang="EN-US">1.0 – 60.0 µg mL<sup>-1</sup> and the limit of detection and quantitation were found as 0.5 and 1.0 µg mL<sup>-1</sup>, respectively. </span></p><p class="Body"><span lang="EN-US"> </span></p>

scholarly journals Determination of Six Metals in Galician Red Wines (in Northwestern Spain) by Capillary Electrophoresis

2000 ◽  
Vol 83 (1) ◽  
pp. 183-188 ◽  
Author(s):  
Mar Núñez ◽  
Rosa M Peña ◽  
Carlos Herrero ◽  
Sagrario García
Keyword(s):  
Fused Silica ◽  
Red Wines ◽  
Indirect Uv Detection ◽  
Sodium Potassium ◽  
Fused Silica Capillary ◽  
Order Of Magnitude ◽  
Northwestern Spain ◽  
Capillary Electrophoretic ◽  
Silica Capillary Column

Abstract A simple technique is described for the routine simultaneous capillary electrophoretic determination of 6 cations in wine. Separation was achieved on a fused silica capillary column with a UV-Cat-1, α-hydroxysobutyric acid and 18-crown-6-ether buffer at pH 4.5 and indirect UV detection at 214 nm. The content of magnesium, sodium, potassium, calcium, manganese, and lithium was determined. The method is quantitative, with recoveries in the 92–102% range, and linear over more than one order of magnitude. The precision is better than 2.5–3.4%. The method is sensible, with detection limits between 0.01 and 0.06 mg/L. Twenty-five red wines with a Certified Brand of Origin from Galicia (northwestern Spain) were analyzed by the proposed method. Various wines showed very similar electrophoretic profiles, but significant quantitative differences were observed.

scholarly journals Development of alternative methods for the determination of raloxifene hydrochloride in tablet dosage form

2015 ◽  
Vol 51 (2) ◽  
pp. 349-360 ◽  
Author(s):  
Fernanda Rodrigues Salazar ◽  
Cristiane Franco Codevilla ◽  
Leonardo Meneghini ◽  
Ana Maria Bergold
Keyword(s):  
Dosage Form ◽  
Background Electrolyte ◽  
Sodium Dodecyl ◽  
Fused Silica ◽  
Uv Detection ◽  
Effective Length ◽  
Alternative Methods ◽  
Pharmaceutical Dosage Form ◽  
Raloxifene Hydrochloride

<p>Three methods are proposed for the quantitative determination of raloxifene hydrochloride in pharmaceutical dosage form: ultraviolet method (UV) high performance liquid chromatography (HPLC) and micellar capillary electrophoresis (MEKC). These methods were developed and validated and showed good linearity, precision and accuracy. Also they demonstrated to be specific and robust. The HPLC and MEKC methods were tested in regards to be stability indicating methods and they showed to have this attribute. The UV method used methanol as solvent and optimal wavelength at 284 nm, obeying Lambert-Beer law in these conditions. The chromatographic conditions for the HPLC method included: NST column C18 (250 x 4.6 mm x 5 µm), mobile phase water:acetonitrile:triethylamine (67:33:0,3 v/v), pH 3.5, flow rate 1.0 mL min<sup>-1</sup>, injection volume 20.0 µl, UV detection 287 nm and analysis temperature 30 °C. The MEKC method was performed on a fused-silica capillary (40 cm effective length x 50 µm i.d.) using as background electrolyte 35.0 mmol L<sup>-1</sup> borate buffer and 50.0 mmol L<sup>-1</sup> anionic detergent sodium dodecyl sulfate (SDS) at pH 8.8. The capillary temperature was 32°C, applied voltage 25 kV, UV detection at 280 nm and injection was perfomed at 45 mBar for 4 s, hydrodimanic mode. In this MEKC method, potassium diclofenac (200.0 µg mL<sup>-1)</sup> was used as internal standard. All these methods were statistically analyzed and demonstrated to be equivalent for quantitative analysis of RLX in tablets and were successfully applied for the determination of the drug.</p>

scholarly journals Validated Method for the Determination of Piroxicam by Capillary Zone Electrophoresis and Its Application to Tablets

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Arın Gül Dal ◽  
Zeynep Oktayer ◽  
Dilek Doğrukol-Ak
Keyword(s):  
Background Electrolyte ◽  
Internal Standard ◽  
Fused Silica ◽  
Electrophoretic Method ◽  
Pharmaceutical Tablets ◽  
Fused Silica Capillary ◽  
Capillary Zone ◽  
The Difference ◽  
Tablet Dosage

Simple and rapid capillary zone electrophoretic method was developed and validated in this study for the determination of piroxicam in tablets. The separation of piroxicam was conducted in a fused-silica capillary by using 10 mM borate buffer (pH 9.0) containing 10% (v/v) methanol as background electrolyte. The optimum conditions determined were 25 kV for separation voltage and 1 s for injection time. Analysis was carried out with UV detection at 204 nm. Naproxen sodium was used as an internal standard. The method was linear over the range of 0.23–28.79 µg/mL. The accuracy and precision were found to be satisfied within the acceptable limits (<2%). The LOD and LOQ were found to be 0.07 and 0.19 µg/mL, respectively. The method described here was applied to tablet dosage forms and the content of a tablet was found in the limits of USP-24 suggestions. To compare the results of capillary electrophoretic method, UV spectrophotometric method was developed and the difference between two methods was found to be insignificant. The capillary zone electrophoretic method developed in this study is rapid, simple, and suitable for routine analysis of piroxicam in pharmaceutical tablets.

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