The aim of this work was to establish the best experimental conditions for the isolation of flunitrazepam and its main metabolite 7-aminoflunitrazepam from human plasma. Several mixtures of solvents (ethyl acetate, tert-butylmethyl ether, hexane, chloroform/ ethyl ether (20/80), dichloromethane / ethyl ether (20/80) and extraction cartridges (Oasis MCX , SepPak C18, Chromafix C18, Oasis HLB) we...

the applicability of hollow fiber-based liquid phase microextraction (hf-lpme) was evaluated for the extraction and preconcentration of loratadine prior to determination by hplc. in order to obtain high extraction recovery, the parameters affecting the hf-lpme including type of organic phase, ph of the source and receiving phases, stirring rate, extraction time and salt addition were studied an...

Purpose: To investigate the effect of β-glucuronidase on the extraction efficiency of silymarin (mainly as silybin) from spiked human plasma using a sensitive and reproducible high performance liquid chromatography (HPLC) method. Methods: The importance of β-glucuronidase was evaluated by comparing the extraction efficiency of silymarin in β-glucuronidase-treated and untreated plasma samples. I...

A rapid and simple organic extraction method for the determination of the chemical warfare agent, isopropyl methylphosphonofluoridate (sarin, GB) in human plasma has been developed using gas chromatography-tandem mass spectrometry (GC-MS/MS). In the course of method development, several organic solvents have been screened and chloroform show a low background and increase signal to noise ratio o...

conclusions it is suggested that determination of the target genotype by plasma subtyping for choosing the proper antiviral therapy is essential but may result in therapy failure. hcv genotyping in pbmc samples, along with plasma specimens, might be more beneficial. therefore determining the hcv genotype in pbmcs, before beginning the therapy is useful due to the possibility of occult infection...

1. Hepatic elimination of renin was measured in 10 well-compensated cardiac patients with normal liver function during a control period and during a period of reduced hepatic plasma flow, induced by physical exercise (seven patients) or intravenous infusion of lysine vasopressin (three patients). 2. Hepatic renin elimination rate (hepatic plasma flow x arterial-hepatic vein difference of plasma...