Liquid chromatographic determination of polydextrose in food matrixes.

A liquid chromatographic (LC) method has been developed to determine the content of polydextrose, a water-soluble 1 calorie/g bulking agent, in food matrixes such as cookies, cakes, fruit spreads, and chocolate toppings. This analysis, which requires use of a blank matrix, provides a feasible means to control the manufacture of foods containing this additive and provides a component for the accurate determination of the caloric value of a particular food product. The method involves aqueous extraction of the polydextrose from the food matrix followed by separation on a carbohydrate analysis column.

High-performance liquid chromatographic determination of cefoperazone in human serum and urine.

A gradient high-performance liquid chromatographic (HPLC) procedure has been developed for the determination of microgram amounts of cefoperazone in human serum and urine. The method employs a muBondapak C18 column and gradient elution with two mobile phases. Excellent separation of the drug from potential degradation products as well as from representative penicillins (sodium ampicillin, sodium methicillin, potassium penicillin G) and aminoglycosides (tobramycin, gentamicin, kanamycin) has been demonstrated.

Determination of polythiazide and prazosin in human plasma by high-performance liquid chromatography.

A selective high-performance liquid chromatographic method has been developed for the determination of polythiazide in human plasma down to concentrations of 0.5 ng/ml. Polythiazide and an internal standard (epithiazide) are simultaneously extracted from the sample, the extract is purified on a silica micro-column and analyzed on a muBondapak CN column.

High pressure liquid chromatographic determination of sorbitol in bulk sorbitol.

An HPLC procedure for determining sorbitol in bulk sorbitol is described. An Aminex HPX-87 column (Bio-Rad) is used with water as a mobile phase and with a refractive index detector to monitor column eluate. Sorbitol is separated from pentaerythritol, erythritol, ribitol, ethylene glycol, propylene glycol, arabitol, galactitol, mannitol, iditol, and other carbohydrates.

High-performance liquid chromatographic determination of (Z)- and (E)-doxepin hydrochloride isomers.

A high-performance liquid chromatographic method for the determination of (Z)- and (E)-doxepin hydrochloride isomers was developed. The analysis employs a column packed with spherical silica microparticles (5-6 mum), and a mobile phase of acetonitrile-chloroform-diethylamine (750:250:0.2) permits baseline resolution and simultaneous determination of the (Z)- and (E)-doxepin isomers.