scholarly journals Determination of Gentamicins C1, C1a, and C2 in Plasma and Urine by HPLC

2000 ◽  
Vol 46 (6) ◽  
pp. 837-842 ◽  
Author(s):  
Nina Isoherranen ◽  
Stefan Soback
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Preparative Chromatography ◽  
Detector Response ◽  
Therapeutic Drug ◽  
Resonance Spectroscopy ◽  
Pharmacokinetic Studies ◽  
Phase Extraction ◽  
Limit Of Quantification

Abstract Background: Gentamicin is an aminoglycoside antibiotic complex containing gentamicins C1, C1a, and C2. Few methods have been described for analysis of the three gentamicin components separately in biological fluids, and none has been used in pharmacokinetic studies. Determination of the three gentamicins separately may have pharmacokinetic and toxicological implications. The present study describes development of an HPLC method for the analysis of gentamicin C1, C1a, and C2 components in plasma and urine. Methods: The three components were isolated by preparative chromatography and their identities verified by thin-layer chromatography, HPLC, mass spectrometry, nuclear magnetic resonance spectroscopy, and melting point determination. The gentamicins were extracted from the biological matrix by use of Tris buffer and polymer phase solid-phase extraction. Derivatization was carried out in the solid-phase extraction cartridge with 1-fluoro-2,4-dinitrobenzene. The 2,4-dinitrophenyl derivatives were separated with reversed-phase HPLC and quantified by the ultraviolet absorbance at 365 nm. Results: The detector response was linear from the limit of quantification to 50 mg/L for the individual components. The limit of quantification was 0.07 mg/L for gentamicin C1 and 0.1 mg/L for gentamicins C2 and C1a. The recovery of the gentamicin components was 72% from plasma and 98% from urine. The method was validated for human and dog plasma and urine. Conclusions: The method was repeatable and enabled the analysis of gentamicins C1, C1a, and C2 in plasma and urine in concentrations covering the therapeutic range of the drug, thus being suitable for therapeutic drug monitoring and pharmacokinetic studies.

scholarly journals Determination of Flumorph Residues in Vegetables, Soil, and Natural Water by Solid-Phase Extraction Cleanup and High-Performance Liquid Chromatography with UV Detection

2008 ◽  
Vol 91 (6) ◽  
pp. 1459-1466 ◽  
Author(s):  
Ji-Ye Hu ◽  
Yu-Chao Zhang ◽  
Hai Yan
Keyword(s):  
Solid Phase Extraction ◽  
Natural Water ◽  
High Performance ◽  
Solid Phase ◽  
Residue Analysis ◽  
Reversed Phase ◽  
Uv Detection ◽  
Phase Extraction ◽  
Limit Of Quantification

Abstract A method for high-performance liquid chromatographic (HPLC) determination of flumorph residues in cucumber, tomato, soil, and natural water was developed and validated. Primary secondary amine or octadecylsilyl (C18) solid-phase extraction cartridges were used for sample preparation. Reversed-phase HPLC with UV detection was used for separation and quantification of the pesticide. The combined cleanup and chromatographic method steps were sensitive and reliable for simultaneous determination of residues of the 2 isomers of flumorph in the studied samples. This method is characterized by recovery >97.9, coefficient of variation <6.2, and limit of quantification of 0.01 mg/kg, in agreement with directives for method validation in residue analysis. Flumorph residues in the samples were further confirmed by HPLC/mass spectrometry. The proposed method is fast, easy to perform, and could be used for monitoring of pesticide residues.

scholarly journals HPLC method validation and application for organic acid analysis in wine after solid-phase extraction

2016 ◽  
Vol 35 (2) ◽  
pp. 225 ◽  
Author(s):  
Violeta Ivanova-Petropulos ◽  
Krste Tašev ◽  
Marina Stefova
Keyword(s):  
Solid Phase Extraction ◽  
Organic Acids ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Hplc Method ◽  
Phase Extraction ◽  
Hplc Separation ◽  
Limit Of Quantification

<p>A solid-phase extraction method followed by reverse phase high-performance liquid chromatography (RP-HPLC) was optimized and validated for the quantitative determination of tartaric, malic, shikimic, lactic, citric and succinic acids in wine. Solid-phase extraction was carried out with C18 cartridges and extraction recoveries for all acids ranging from 98.3 to 103% were obtained. HPLC separation was performed with isocratic elution on a LiChrosorb RP-18 column (250 × 4.6 mm I.D., 5 µm) protected with the appropriate guard column. The mobile phase was a 5 mM solution of H<sub>3</sub>PO<sub>4</sub> with pH 2.1 at a flow rate of 1 ml/min. Detection of the organic acids was performed at 210 nm. The developed method was validated by checking its linearity, limit of detection (LOD), limit of quantification (LOQ), precision and recovery. The method was applied to the analysis of organic acids in Macedonian red and white wines.</p>

scholarly journals Optimization and validation of bioanalytical SPE – HPLC method for the simultaneous determination of carbamazepine and its main metabolite, carbamazepine-10, 11-epoxide, in plasma

2011 ◽  
Vol 57 ◽  
pp. 53-61
Author(s):  
Jasmina Tonic – Ribarska ◽  
Zoran Sterjev ◽  
Emilija Cvetkovska ◽  
Igor Kuzmanovski ◽  
Gordana Kiteva ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Simultaneous Determination ◽  
Solid Phase ◽  
Therapeutic Monitoring ◽  
Therapeutic Drug ◽  
Phase Extraction ◽  
Plasma Samples ◽  
Epileptic Patients ◽  
Pharmacologically Active

Carbamazepine is widely used as an antiepileptic drug in the treatment of partial and generalized tonic-clonic seizures. Carbamazepine 10,11-epoxide is the most important metabolite of carbamazepine, because it is a pharmacologically active compound with anticonvulsant properties. According to that, the routine analysis of carbamazepine 10,11-epoxide along with carbamazepine may provide optimal therapeutic monitoring of carbamazepine treatment. The aim of this study was to optimize and validate a simple and reliable solid - phase extraction method followed by RP-HPLC for the simultaneous determination of plasma levels of carbamazepine and carbamazepine-10,11-epoxide, in order to assure the implementation of the method for therapeutic monitoring. The extraction of the analytes from the plasma samples was performed by means of a solid-phase extraction procedure. The separation was carried out on a reversed-phase column using isocratic elution with acetonitrile and water (35:65, v/v) as a mobile phase. The temperature was 30°C and UV detection was set at 220 nm. The extraction yield values were more than 98% for all analytes, measured at four concentration levels of the linear concentration range. The method displayed excellent selectivity, sensitivity, linearity, precision and accuracy. Stability studies indicate that stock solutions and plasma samples were stabile under different storage conditions at least during the observed period. The method was successfully applied to determine the carbamazepine and carbamazepine-10,11-epoxide in plasma of epileptic patients treated with carbamazepine as monotherapy and in polytherapy. In conclusion, the proposed method is suitable for application in therapeutic drug monitoring of epileptic patients undergoing treatment with carbamazepine.

scholarly journals Determination and Validation of a Solid-phase Extraction Gas Chromatography-mass Spectrometry for the Quantification of Methadone and Its Principal Metabolite in Human Plasma

2015 ◽  
Vol 10 ◽  
pp. ACI.S25554 ◽  
Author(s):  
Fouad Chiadmi ◽  
Joël Schlatter
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solid Phase Extraction ◽  
Human Plasma ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Therapeutic Drug ◽  
Pharmacokinetic Studies ◽  
Phase Extraction ◽  
Relative Standard

This study aimed to develop a solid-phase extraction gas chromatography-selected ion monitoring-mass spectrometry method for the determination of methadone (MDN) and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in human plasma. The linear response was obtained over the concentration range from 10 to 2000 ng/mL for MDN and EDDP. The absolute recoveries of MDN and EDDP were 95.9%-98.9% and 94.8%-102.4%, with relative standard deviation (RSD) ranging from 1.8% to 2.7% and 1.8% to 3.9%, respectively. The intra- and interday precisions were found to be less than 5% for both analytes. The limits of detection of MDN and EDDP were 4 and 5 ng/mL, respectively. The presented method was convenient for therapeutic drug monitoring and pharmacokinetic studies in patients on heroin-assisted MDN therapy.

Determination of pinocembrin in human plasma by solid-phase extraction and LC/MS/MS: application to pharmacokinetic studies

2014 ◽  
Vol 28 (12) ◽  
pp. 1601-1606 ◽  
Author(s):  
Bei Yan ◽  
Guoying Cao ◽  
Taohua Sun ◽  
Xi Zhao ◽  
Xin Hu ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Human Plasma ◽  
Solid Phase ◽  
Pharmacokinetic Studies ◽  
Phase Extraction

scholarly journals HPLC Method with Solid-Phase Extraction for Determination of (R)- and (S)-Ketoprofen in Plasma without Caffeine Interference: Application to Pharmacokinetic Studies in Rats

2013 ◽  
Vol 52 (10) ◽  
pp. 1204-1210 ◽  
Author(s):  
Francisco Javier López-Muñoz ◽  
Nancy Vara Gama ◽  
Olivia Soria-Arteche ◽  
Marcela Hurtado y de la Peña ◽  
Adriana Miriam Domínguez-Ramírez ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Hplc Method ◽  
Pharmacokinetic Studies ◽  
Phase Extraction

scholarly journals Determination of Ranitidine in Human Plasma by SPE and ESI-LC-MS/MS for Use in Bioequivalence Studies

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Karini B. Bellorio ◽  
Maria Isabel R. Alves ◽  
Nelson R. Antoniosi Filho
Keyword(s):  
Solid Phase Extraction ◽  
Human Plasma ◽  
Extraction Method ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Internal Standard ◽  
Phase Extraction ◽  
Good Separation ◽  
Limit Of Quantification

A method for determining ranitidine in human plasma by ESI-LC-MS/MS was validated, using propranolol as internal standard. The extraction method used was solid phase extraction (SPE). Chromatographic separation was performed in a Chromolith C18 (50 mm × 4.6 mm i.d.) analytical column, which provided good separation of ranitidine and propranolol peaks with an analysis time of 2.5 minutes. Extraction yields of 94.4% for ranitidine and 89.4% for the internal standard were obtained. The lower limit of quantification (LLOQ) was 3.00 ng/mL, and limit of detection (LOD) was 0.05 ng/mL, with linearity ranging from 3.00 to 500 ng/mL. The results, thus, showed that this method is suitable for application in bioequivalence studies of ranitidine in human plasma.

A multidrug LC–MS/MS method for the determination of five immunosuppressants in oral fluid

Bioanalysis ◽  
2019 ◽  
Vol 11 (16) ◽  
pp. 1509-1521 ◽  
Author(s):  
Lucía Paniagua-González ◽  
Elena Lendoiro ◽  
Esteban Otero-Antón ◽  
Esther Molina-Pérez ◽  
Evaristo Varo-Pérez ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Solid Phase Extraction ◽  
Mobile Phase ◽  
Oral Fluid ◽  
Solid Phase ◽  
Therapeutic Drug ◽  
Phase Extraction ◽  
Trough Concentrations ◽  
First Time

Aim: This study aimed: to develop and validate an LC–MS/MS method for mycophenolic acid, tacrolimus, sirolimus, everolimus and cyclosporin A in oral fluid (OF), as an essential tool to study the usefulness of OF as an alternative matrix for immunossuppressants’ therapeutic drug monitoring; and to find the best OF collector for these analytes. Materials & Methods: Chromatographic separation was achieved using an XBridge® Shield RP18 analytical column maintained at 65ºC, using 2 mM ammonium formate and 0.1% formic acid in water (A) and acetonitrile (B) as mobile phase. OF sample was extracted with solid phase extraction after sonication and protein precipitation. Results & Conclusions: Method validation met all the acceptance criteria. LODs were 0.05–1 ng/ml, and LOQs 0.1–5 ng/ml. Silanized tubes offered the best recoveries. The method was successfully applied to 31 OF specimens, describing everolimus detection in OF for the first time. Conclusion: The proposed method is sensitive enough for the detection of OF trough concentrations in patients receiving immunosuppressants when using an appropriate OF collector.

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