Michael E. Swartz, Ph.D. Principal Scientist, Waters Corporation, Milford, Massachusetts, e-mail [email protected]. igh performance liquid chromatography (HPLC) is a proven technique that has been used in laboratories worldwide over the past 30-plus years. One of the primary drivers for the growth of this technique has been the evolution of packing materials used to effect the separatio...

Diisopropyl fluorophosphate (DFP) has been shown to be a remarkably potent inhibitor of the enzymatic hydrolysis of acetylcholine (1). As a result of a wide survey (2), inhibition by dialkyl fluorophosphates appears to be specific for certain esterases and lipases (kidney acid phosphatase was found to be inhibited by relatively high concentrations). Since the cholinesterase of mammalian brain a...

The influence of different parameters on the sorption profiles of trace and ultra traces of gold (I) species from the aqueous cyanide media onto the solid sorbents ion exchange polyurethane foams (IEPUFs) and commercial unloaded polyurethane foams (PUFs) based polyether type has been investigated. The retention of gold (I) species onto the investigated solid sorbents followed a first-order rate...

Fumigants differ from other types of insecticides in that the fumes must be confined so that the insect is exposed to a considerable concentration for some time. The length of exposure and the strength of the concentration are interrelated—the higher the concentration, the shorter the lethal exposure; the lower the concentration, the longer the exposure. Fumigants therefore are not well adapted...

A simple, fast, precise reverse phase isocratic high performance liquid chromatographic (HPLC) method has been developed for the simultaneous estimation of Olmesartan medoxomil (OM) and hydrochlorothiazide (HCTZ) in marketed formulations. Estimation of drugs in this combination was done with a C18 column [ODS UG 5 column, 250mm x 4.5mm] using mobile phase of composition acetonitrile and phospha...