A simple and sensitive method by high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) has been investigated for the simultaneous determination of dimethylamphetamine (DMA), its specific yet labile main metabolite dimethylamphetamine-N-oxide (DMAO), and other metabolites, methamphetamine (MA) and amphetamine (AP), in urine. A combination of Bond Elut SCX c...

A sensitive and specific high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS-MS) method has been developed at our center for the determination of glimepiride in human plasma. After the addition of the internal standard, plasma samples were extracted by liquid-liquid extraction technique using diethyl ether. The compounds were separated on a prepa...

Methods to sequentially extract and fractionate wheat flour proteins were evaluated to reliably quantify gliadins, glutenins, and albumins/globulins in single flour samples. Compositions of the resulting protein fractions were analyzed by RP-HPLC combined with SDS-PAGE. Unknown proteins were identified by mass spectrometry or N-terminal sequencing. The best separation and recovery of discrete a...

Analytical isotachophoresis has proved to be an excellent method for separation and quantitative measurement of ionic species in biologic fluids. Isotachophoretic separation of cations in presence of a complex-forming nonionic detergent (e.g. Triton X-100) in 98% methanol enables simultaneous quantitative determination of ammonium, sodium, potassium, magnesium, and protonated creatinine in urin...

Most common prostaglandin analogs, bimatoprost, latanoprost and travoprost, are licensed for the reduction of elevated intraocular pressure in patients with open angle glaucoma and ocular hypertension, but their non approved use as eyelash enhancers is becoming popular, especially in patients with eyelashes hypotrichosis. A fast and sensitive high performance liquid chromatography tandem mass s...

a sensitive and selective extraction - spectrophotometric method for the determination of trace amounts of palladium is reported. the method is based on quantitative extraction of brownish tetrabutylammoium tetraiodopalladium (ii) ion pair into a small valume of chloroform at ph 1.3-12.0, followed by spectrophotometric measurements. the beer's law is obeyed over the range 0.02-1.09 mgml-1 at 44...

OBJECTIVE To develop a liquid-liquid extraction based reverse phase liquid chromatography method for estimation of montelukast in rabbit plasma. METHODS Chromatographic separation was carried out using Phenomenex Luna C18 column (250 mm × 4.6 mm × 5 μm) with mobile phase composed of ammonium acetate buffer (20 Mm), pH 5.5 and acetonitrile in 20:80, v/v ratio. The analyte was monitored with UV...

An extraction-spectrophotometric method for the determination of trace amounts of ammonium ion is described. Ammonium ion is effectively extracted as a neutral ternary complex NH . DB 18C6. calmagite at pH 3.0 into chloroform, followed by spectrophotometric determination at =48 5 nm. Molar absorptivity of the ternary complex at this wavelength is 1.08 10 mol cm . Beer's law is obeyed over...