Background In a system of two immiscible liquids, usually water (or an aqueous solution) and an organic liquid (e.g. an oil), there are two general types of dispersions which can be formed depending on the conditions of the system. A water-in-oil (W/O) dispersion is a dispersion formed when the aqueous phase is dispersed in the organic phase and an oil-in-water (O/W) dispersion is a dispersion ...

This paper describes the development of a method for the simultaneous determination of ten anticoagulant rodenticides (coumafuryl, warfarin, pindone, coumatetralyl, coumachlor, difenacoum, bromadiolone, brodifacoum, chlorophacinone and flocoumafen) in the liver and kidney based on column-switching liquid chromatography coupled with heated electrospray ionization tandem mass spectrometry. The si...

We here report a reversed-phase HPLC method for the determination of free cortisol in human urine, using methylprednisolone as the internal standard. Before chromatography, samples were extracted with a C18 solid-phase extraction column and the steroids were separated on a LiChrospher 100 C18 column with a mobile phase of methanol/acetonitrile/water (43/3/54 by vol). Linearity, precision, and a...

A rapid, simple and sensitive high-performance liquid chromatography method was developed for determination of ciprofloxacin in plasma by means of ultraviolet detection. Ofloxacin was used as an internal standard and separation carried on a Novapak C18 column using a mobile phase of 0.01 M phosphate buffer (pH =2.6): methanol (82: 18 v/v). Extraction of drug was performed from plasma by liquid-...

A new column packing, SP-2510 DA (Supelco, Inc., Bellefonte, Pa. 16823), is an excellent stationary phase for the determination of a wide variety of anticonvulsant drugs by gas--liquid chromatography without derivatization. However, when uncomplicated extraction procedures are used, serum cholesterol interferes with the determination of primidone. By the simple expedient of adding a short "pre-...

Sulfonamides were extracted from honey with acetate buffer (pH 5.0), and cleaned up by solid phase extraction (SPE) procedure. The liquid chromatography (LC) separation was carried out on RP C18 column using acetic acid and acetonitrile as the mobile phase in gradient mode and monitored with fluorescence detector, after pre-column derivatisation. Recoveries from spiked honey were above 80%, and...

A rapid, simple and sensitive high-performance liquid chromatography method was developed for determination of ciprofloxacin in plasma by means of ultraviolet detection. Ofloxacin was used as an internal standard and separation carried on a Novapak C18 column using a mobile phase of 0.01 M phosphate buffer (pH =2.6): methanol (82: 18 v/v). Extraction of drug was performed from plasma by liquid-...

a rapid and reproducible method is described that employs solid phase extraction (spe) using dichloromethane, followed by gas chromatograph-mass spectrometry for the determination of toxic toluene, xylene and cumene (txc) from different lake water of dhaka mega city of bangladesh. the method was applied to detect and quantify txc in water samples collected from surface and 30 cm depth of water....

A solid-phase extraction absorbent material based on poly (N-isopropylacrylamide-comethacrylic acidco-ethylene glycol dimethacrylate) [poly (NIPAAm-MAA-co-EDMA)] monolithic column was developed for the simultaneous determination of nitrendipine and nisoldipine from human urine. The morphology of monolithic column and pressure drop across the columns were characterized. The results showed excell...

The effects and influences of various operational parameters on the efficiency of mixer-settlers are thoroughly studied in this paper. One of the most important factors in designing a mixer-settler is to obtain an optimum operational extraction and overall efficiency. These two factors are dependent on various parameters such as impeller shape, size and speed of impeller, baffle size, residence...