Desmosterol (24-dehydrocholesterol) is the immediate precursor of cholesterol in the biosynthesis of the latter compound. The structures of these two sterols are very similar, and desmosterol interferes with many of the colorimetric methods used for estimating plasma cholesterol levels. Normally, desmosterol is not present in plasma in significant amounts, but in patients treated with triparano...

We describe a modified colorimetric method for determining procainamide in plasma by use of a diazotization and coupling reaction with N-(1-naphthyl)-ethylenediamine dihydrochloride (Marshall's reagent). The sensitivity of the assay is increased twofold over the originally reported colorimetric method, and the lower limit of detection for the assay of a 1.0-ml plasma sample has been decreased t...

A field-amplified sample stacking and capillary electrophoresis with UV detection was described for the determination of doxorubucin and doxorubicinol in human plasma. After sample pretreatment, field-amplified sample stacking method was applied for sensitive improvement. The sample was employed with an electrokinetic injection of 10 kV for 30 sec. The capillary electrophoresis separation of do...

BACKGROUND Measurement of methylmalonic acid (MMA) in serum or plasma is useful for diagnosing cobalamin deficiency. We developed a method for quantifying MMA in plasma based on hydrophilic interaction liquid chromatography (HILIC) and single-stage negative electrospray ionization (ESI) mass spectrometry. METHODS We deproteinized plasma samples (200 microL) with 800 microL acidified acetonitr...

We have studied the formation of relativistic solitary waves due to nonlinearinteraction of strong electromagnetic wave with the plasma wave. Here, our plasma isrelativistic both in temperature and in streaming speed. A set of equations consisting ofscalar and vector potentials together with a third order equation for the enthalpy inphoton gas plasma is obtained analytic...

A rapid glycomic profiling method is described wherein N-glycans from plasma samples individually labelled with aniline, 2-aminobenzamide and 2-aminoacridone are mixed, co-injected and separated in the same HILIC-fluorescence run. Transfer of the multiplexed method to UPLC-fluorescence permits an increase in sample throughput from 24 to 864 plasma samples per day.

A simple, sensitive isocratic method for the detection and quantification of ciprofloxacin in plasma and urine has been developed. The assay consisted of reversed-phase HPLC with ultraviolet detection. Plasma proteins were removed by a fast and efficient procedure. For the urine samples, the only required sample preparation was dilution. Separation was achieved on a C18 reversed-phase column. T...

background: omeprazole is metabolized predominantly by cyp2c19, a polymorphically expressed enzymes that show marked interindividual and interethnic variation. these variations cause a substantial differences that have been reported in the pharmacokinetics of omeprazole. the aim of the present study was to evaluate the pharmacokinetic parameters of omeprazole in a random iranian population. met...