A comparative study of the reversed-phase HPLC retention behaviour of S-adenosyl-L-methionine and its related metabolites on Hypersil ODS and Supelcosil LC-ABZ stationary phases.

S-Adenosyl-L-methionine (SAM) and its metabolites S-adenosyl-L-homocysteine (SAH) and methyl-thioadenosine (MTA) are endogenous compounds that are heavily involved in a variety of biochemical processes, and have therefore been the target for several assays in body fluids and tissues. Reversed-phase chromatographic behaviour of SAM and its metabolites has been studied by using Supelcosil LC-ABZ column, specially designed for analysis of acidic, basic, zwitterionic and neutral compounds, and on a Hypersil ODS column as a function of mobile phase pH. The retentions of the compounds, expressed by the capacity ratio (k'), are measured on both column with mobile phases comprised of 10% acetonitrile and 10 mM ammonium formate buffer with pH values ranging from 2 to 9.

Simultaneous high-performance liquid chromatographic determination of propoxyphene and acetaminophen in pharmaceutical preparations.

A normal-phase high-performance liquid chromatographic method, using a 3.3 cm x 4.6 mm silica column (3 microns packing) and an ammonium hydroxide-methanol-dichloromethane mobile phase, has been developed to separate propoxyphene and acetaminophen in less than 5 min.