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counterfeit drugs. Fluorescence detection in liquid chromatography is a powerful method that not only complements conventional UV absorption methods, but also, in many instances, achieves specificity that make it a more desirable method of adulteration

Open access

Summary

A simple and rapid high-performance liquid chromatographic method with fluorescence detection for analysis of loratadine (LOR) in small volumes of human serum has been developed and validated. After solid-phase extraction (SPE), with thioridazine hydrochloride as internal standard, chromatographic separation was performed on a C18 analytical column with 70:30 (v/v) acetonitrile-water, adjusted to pH 2.7 with orthophosphoric acid as mobile phase at a flow-rate of 1 min mL−1. The column was maintained at 28°C. Fluorescence detection was performed at excitation and emission wavelengths of 265 of 454 nm, respectively. The method was validated for accuracy, precision, selectivity, linearity, recovery, and stability. Absolute recovery of LOR was >93.0%. The limits of detection (LOD) and quantification (LOQ) were 0.07 and 0.2 ng mL−1, respectively. Linearity was confirmed in the range 0.2–30 ng mL−1 (correlation coefficient >0.9998). This HPLC method is selective, robust, and specific and would enable efficient analysis of large numbers of serum samples in support of pharmacokinetic, bioavailability, or bioequivalence studies after therapeutic doses of LOR.

Open access

Summary

A simple and sensitive method of high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was developed for the determination of icariin in capsules by precolumn chelation with aluminum. In order to obtain a stable fluorescence signal, the reaction conditions of the fluorescent chelation complex between icariin and aluminum were investigated in detail. Chromatography was carried out on an Agilent Zorbax Extend C18 column (150 mm × 4.6 mm, 5.0 μm) using methanol as mobile phase at a flow rate of 1.0 mL min−1. The excitation and emission wavelengths were set at 430 and 480 nm, respectively. At optimum conditions, the calibration curve was linear in the concentration range from 0.010 to 100.0 μg mL−1 with the limit of detection of 3.5 ng mL−1 (S/N = 3). A comprehensive method was validated for precision and accuracy. The method described here has been successfully applied for the determination of the icariin content in a capsule with satisfactory results.

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(QL) which are essential for plasma analysis. Therefore, the aim of this work was to establish a fast and simple HPLC method with fluorescence detection, due to its high sensitivity, for the simultaneous determination of TM, IB and CL in

Open access

Summary

Capillary electrophoresis with fluorescence detection has been investigated for simple, sensitive, and selective analysis of morphine and 6-acetylmorphine (6-AM) in human urine. The method is based on the reaction of morphine and 6-AM with the freshly prepared diazonium salt of aniline at 0°C. The method is selective in the presence of codeine. Conditions that affect derivatization (diazonium concentration and reaction time) and separation (electrolyte concentration, pH, β-cyclodextrin concentration, organic additives, and separation potential) were studied. When fluorescence detection was used with an excitation wavelength of 350 nm and an emission cutoff filter of 500 nm, good linearity was obtained in the range of 50–2000 ng mL–1 with limits of detection and quantification below 1.0 and 3.3 ng mL–1, respectively. The method was applied to human urine and validated by comparison with previously established capillary electrophoretic methods. Accuracy, repeatability, and intermediate precision of results were comparable. The method is suitable for application in forensic cases for initial screening, and in clinical analysis to prevent overdose-induced toxicity.

Open access

pharmacokinetic study, a simple and reliable RP-HPLC method with fluorescence detection was developed and applied for simultaneous analysis of MCPT and its active metabolites HCPT in bile, urine, and feces collected from i.v. administered male Wistar rats. The

Open access

, M. M. ; Michael , M. A. A fast and green reversed-phase HPLC method with fluorescence detection for simultaneous determination of amlodipine and

Open access
Acta Veterinaria Hungarica
Authors:
Diana Žele
,
Silvestra Kobal
,
Gorazd Vengušt
,
Andrej Bidovec
,
Anton Vengušt
, and
Gabrijela Tavčar-Kalcher

A sensitive and reliable method for the determination of trace amounts of abamectin in muscles, kidneys and fat tissue of fallow deer is presented. Abamectin was extracted from the tissues with acetonitrile and the extract was cleaned up on a C8 solid-phase extraction cartridge. Abamectin residue was derivatised with trifluoroacetic acid anhydride and 1-methylimidazole, and determined using reversed- phase high-performance liquid chromatography under isocratic conditions and fluorescence detection. The recoveries of the method were high and consistent, ranging from 78% to 90%. The limit of detection of the method was below 1 μg/kg when analysing muscle, kidney and fat tissue. Matrix-matched calibration was used in order to obtain accurate values and to avoid matrix interference.

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A high-performance thin-layer chromatographic (HPTLC) method has been developed for determination of polyamines in beers. Beer samples, previously degassed, were derivatized with dansyl chloride and the dansyl derivatives were separated by HPTLC with silica gel as stationary phase and chloroform–triethylamine, 2 + 1 (v/v), containing 5% (m/v) polyoxyethylene-10-lauryl ether, as mobile phase. Quantitative analysis was achieved by in-situ fiberoptic-based fluorescence scanning. The compounds were determined over the range 0.5–85 ng, with relative standard deviations between 0.44–1.16% and detection limits in the range 0.28–0.39 ng. The simple preparation of the sample and the rapid microwave-assisted dansylation considerably reduce analysis time and effort.

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This study examines the occurrence of aflatoxins (AFS) and ochratoxin A (OTA) in bread and durum wheat samples. A total of 141 samples were collected from eleven different regions of Turkey. An analytical method based on liquid extraction, immunoaffinity column (IAC) clean-up followed by high performance liquid chromatography (HPLC) was used for the determination of AFs and OTA levels. As a result, AFs and OTA were detected in 2% and 9.2% of wheat samples at concentrations varying from 0.21 to 0.44 µg kg−1 and from 0.1 to 3.2 µg kg−1, respectively. Aflatoxin B1 (AFB1) and aflatoxin B2 (AFB2) were found positive in samples ranging between 0.21–0.35 µg kg−1 and 0.094 µg kg−1, respectively. However, none of the samples contained aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2). The study also recommended that contamination levels in wheat and wheat-based products should be routinely monitored in greater sample numbers to insure food safety.

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