separation of ten sedative- hypnotic drugs was performed by rp-hplc using mixed micellar mobile phase. effect of temperature, type and amount of organic modifier in mobile phase on efficiency (n) and asymmetry factor (b/a) showed that, the appropriate conditions for a good separation were 35°c and 7% (v/v) butanol in mobile phase.  variations of selectivity factor versus butanol concentration, ...

results under the above chromatography condition, biuret compound (peqb) and the internal standard were detected at 4.5 and 13.5 minutes, respectively. limit of quantitation of the peqb was 0.1 µg/ml. accuracy of the method over the concentration range of 0.1-100 µg/ml was between 88-109%. inter- and intraday precisions were 4-19% and 6-8%, respectively. a good relationship in the form of a pow...

background ziziphora tenuior l. known as kakuti in persian, is used in traditional medicine for fever, dysentery, uterus infection and as an analgesic. it is used also in the treatment of gastrointestinal disorders as carminative, or remedy of diarrhea or nausea. major components of plant essential oil including pulegone, isomenthone, thymol, menthone, and piperitone are suggested to be respons...

background aflatoxins are one of the most potent toxic substances that occur naturally. nowadays extensive attention has been taken to their existence in food and environment, as there is the possibility of harm to humans following chronic exposure to extremely low levels via food chain. aflatoxin m1 (afm1) is a hepatic carcinogenic metabolite found in the milk of lactating animals fed with con...

background valproic acid is widely used as an anticonvulsant and mood-stabilizing drug in the treatment of epilepsy. determination of serum valproic acid is required in epilepsy therapy for efficient control of seizures. objectives in the present study, the gas chromatography method was applied to determine serum valproic acid and resulting data were compared with those obtained by high perform...

background and objectives: furfural (f) and hydroxymethyl furfural (hmf) are cyclic aldehydes, which are formed during the heat processing of foods. these chemical contaminants have received much attention due to their suspected health hazards and heat damage indicators. the aim of the present study was extraction and determination of f and hmf in baby-foods using dispersive liquid-liquid micro...

background aflatoxins are a group of very toxic compounds produced by a fungal species and are found in food products. aflatoxin m1 (afm1) is a type found in dairy products and resistant to pasteurization. afm1 can adversely affect hepatocytes in human and leading to various liver diseases. thus, it is essential to examine raw milk for the presence of afm1. conclusions according to the results ...

dispersive liquid-liquid microextraction method (dllme) combined with high-performance liquid chromatography-ultraviolet detection (hplc-uv) was used to determine thiamine (b1), nicotinamide (b3) and pyridoxine (b6) in sour cherry juice. this method was rapid, simple and sensitive. separation was accomplished using a c18 column. the optimum chromatographic conditions were found to be: mobile ph...

in previous studies, mebudipine, a dihydropyridine calcium channel blocker, showed a considerable potential to be used in cardiovascular diseases. the aim of the current study was to develop a valid method using reversed-phase high performance liquid chromatography coupled with electrospray ionization mass spectrometry to assay mebudipine in the human plasma. separation was achieved on a zorbax...

the efficacy of activation methods and coupling were studied in the context of performance in batch and fixed bed binding experiments utilizing cell culture fluids or blood plasma as feedstock. conclusions were drawn regarding selection of solid phase according to pore size, rigidity, ph stability, chemistry of derivation and activation, and gross concentration of immobilized ligand required fo...