September 2009, Sunnyvale, CA— Dionex announces a new method for the separation of oxytocin and acetate in a single chromatographic run using the Acclaim^® Mixed Mode WAX-1 column. Application Note 234: Simultaneous Determination of Pharmaceutical Peptides and Acetate by HPLC with UV Detection Using the Acclaim Mixed-Mode WAX-1 Column demonstrates good separation of acetate and oxytocin in a single injection.

Oxytocin is a neuropeptide with therapeutic uses and is available as an acetate salt. The use of acetate as a counterion in peptide therapeutics is common and is found in a variety of small peptides. AN 234 demonstrates simultaneous determination of acetate in four peptides, with the effective separation of the peptide of interest—acetate—and peptide impurities in >30 minutes. By using a 2.1 mm format column and simultaneously determining acetate and oxytocin, the method provides faster total analysis time, uses only 13% of the solvent required for the USP methods, and generates significantly less waste.

Dionex (NASDAQ:DNEX) is a global leader in the manufacturing and marketing of liquid chromatography and extraction systems, consumables, and software for chemical analysis. The Company's systems are used worldwide in environmental analysis and by the life sciences, chemical, petrochemical, food and beverage, power generation, and electronics industries. Our expertise in applications and instrumentation helps analytical scientists to evaluate and develop pharmaceuticals, establish environmental regulations, and produce better industrial products.

Acclaim is a registered trademark of Dionex Corporation.