Determination of saterinone enantiomers in plasma samples with an internal standard using a Chiralcel OD column, fractionation and reversed-phase chromatography

1990 ◽  
Vol 535 ◽  
pp. 263-269 ◽  
Author(s):  
Martin Rudolph ◽  
Dagmar Volk ◽  
Gerhard Schmiedel
2013 ◽  
Vol 96 (2) ◽  
pp. 265-275 ◽  
Author(s):  
Robert J Goldschmidt ◽  
Wayne R Wolf

Abstract A single-laboratory validation was performed for a method that determines pyridoxine, one of the B6 vitamers, in dietary supplements using LC and UV, fluorescence, or MS detection. The method was adapted for use with either HPLC or ultra-performance LC (UPLC). Pyridoxine is extracted from samples using 0.1 M formic acid, and specific conditions are adjusted for each of the different types of supplement materials examined. Reversed-phase chromatography with C18-based columns is used in both HPLC and UPLC. Fluorescence detection, often used in chromatographic analyses of vitamin B6 in foods, was successfully used here, but offered no great advantages over UV detection in the supplement materials tested. MS detection was also satisfactory, although use of an internal standard was required. Accuracy of the method was demonstrated in several ways, including use of a standard reference material. Precision and repeatability of the method were found acceptable by analysis of variance and HorRat repeatability calculations.


2007 ◽  
Vol 4 (1) ◽  
pp. 109-116 ◽  
Author(s):  
K. Basavaiah ◽  
B. C. Somashekar

A rapid, highly sensitive high performance liquid chromatographic method has been developed for the determination of finasteride(FNS) in bulk drug and in tablets. FNS was eluted from a ODS C18reversed phase column at laboratory temperature (30 ± 2°C) with a mobile phase consisting of methanol and water (80+20) at a flow rate of 1 mL min-1with UV detection at 225 nm. The retention time was ∼ 6.1 min and each analysis took not more than 10 min. Quantitation was achieved by measurement of peak area without using any internal standard. Calibration graph was linear from 2.0 to 30 μg mL-1with limits of detection (LOD) and quantification (LOQ) being 0.2 and 0.6 μg mL-1, respectively. The method was validated according to the current ICH guidelines. Within-day co efficients of variation (CV) ranged from 0.31 to 0.69% and between-day CV were in the range 1.2-3.2%. Recovery of FNS from the pharmaceutical dosage forms ranged from 97.89 – 102.9 with CV of 1.41-4.13%. The developed method was compared with the official method for FNS determination in its tablet forms.


2017 ◽  
Vol 20 (2) ◽  
pp. 241-249 ◽  
Author(s):  
A. Jasiecka-Mikołajczyk ◽  
J.J. Jaroszewski

Abstract Tigecycline (TIG), a novel glycylcycline antibiotic, plays an important role in the management of complicated skin and intra-abdominal infections. The available data lack any description of a method for determination of TIG in avian plasma. In our study, a selective, accurate and reversed-phase high performance liquid chromatography-tandem mass spectrometry method was developed for the determination of TIG in turkey plasma. Sample preparation was based on protein precipitation and liquid-liquid extraction using 1,2-dichloroethane. Chromatographic separation of TIG and minocycline (internal standard, IS) was achieved on an Atlantis T3 column (150 mm × 3.0 mm, 3.0 μm) using gradient elution. The selected reaction monitoring transitions were performed at 293.60 m/z → 257.10 m/z for TIG and 458.00 m/z → 441.20 m/z for IS. The developed method was validated in terms of specificity, selectivity, linearity, lowest limit of quantification, limit of detection, precision, accuracy, matrix effect, carry-over effect, extraction recovery and stability. All parameters of the method submitted to validation met the acceptance criteria. The assay was linear over the concentration range of 0.01-100 μg/ml. This validated method was successfully applied to a TIG pharmacokinetic study in turkey after intravenous and oral administration at a dose of 10 mg/kg at various time-points.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Małgorzata Olejnik ◽  
Piotr Jedziniak ◽  
Teresa Szprengier-Juszkiewicz

The control of levels of anticoccidial feed additives in targeted feeds plays an important role in the assurance of efficiency of animal treatment, prevention of drug resistance, and food safety. The robust and labour-efficient method for the simultaneous determination of six ionophore coccidiostats (lasalocid, maduramicin, monensin, narasin, salinomycin, and semduramicin) in targeted feed has been developed. Properly grinded and homogenized feed sample was spiked with internal standard (monesin methyl ester) and extracted with methanol. The extract was analysed with reversed phase HPLC without any further purification. The separation of the analytes with conventional C18 and core-shell columns was compared. Lasalocid was analysed with fluorescence detection, whereas other ionophores were detected with UV-Vis detector after derivatisation with vanillin in the presence of sulfuric acid. Fortified samples and targeted feeds at authorized levels were used for method validation. Recovery was in the range of 85–110%, depending on the analyte. The within-laboratory reproducibility did not exceed the target value from Horwitz equation. The results of the proficiency tests (z-scores in the range of −1.0 to 1.9) confirmed the reliability of the developed protocol.


1984 ◽  
Vol 30 (7) ◽  
pp. 1228-1230 ◽  
Author(s):  
A K Dhar ◽  
H Kutt

Abstract This method for determination of haloperidol in plasma is based on "high-performance" isocratic liquid chromatography with the use of a C8 bonded reversed-phase column at room temperature. Haloperidol and the internal standard (chloro-substituted analog) are extracted from alkalinized plasma into isoamyl alcohol/heptane (1.5/98.5 by vol) and back-extracted into dilute H2SO4. The aqueous phase is directly injected onto the column. The mobile phase is a 30/45/25 (by vol) mixture of phosphate buffer (16.5 mmol/L, pH 7.0), acetonitrile, and methanol. Unlike other liquid-chromatographic procedures for haloperidol, commonly used psychotropic drugs do not interfere. Analysis can be completed within an hour. The procedure is extremely sensitive (1.0 microgram/L) and is well reproducible (CV 5.6% for a 2.5 micrograms/L concentration in plasma).


1980 ◽  
Vol 26 (13) ◽  
pp. 1825-1828 ◽  
Author(s):  
M J Herfst ◽  
P M Edelbroek ◽  
F A de Wolff

Abstract A method is described for determination of 8-methoxypsoralen to 0.2 mL of suction-blister fluid or 1 mL of serum from psoriatic patients being treated with this drug. The drug is extracted from the biological matrix at pH 9.0 with a mixture of dichloromethane and light petroleum ether. 5-Methoxypsoralen is used as internal standard. Separation and quantitation are performed on a “high-performance” liquid chromatograph with use of an RP 18 reversed-phase column and detection at 245 nm. Accuracy and precision are good. Some benzodiazepines and their metabolites interfere. The lowest detectable concentration is 10 microgram/L, which means that the method is sufficiently sensitive to measure the drug concentrations in serum and suction-blister fluid for pharmacokinetic studies in patients being treated with a therapeutic dosage.


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