Qualitative thin-layer and high-performance liquid chromatographic analysis of 1-substituted diazen-1-ium-1,2- diolates on aminopropyl-bonded silica gel

High-performance liquid (HPLC) and thin-layer (TLC) chromatographic methods for the detection and quantification of diazeniumdiolates are described. The HPLC determinations were made using a Rocket Platinum NH2 column (7 x 53 mm, 100- Angstrom pore size, 3-mum particle size), under isocratic conditions with mixtures of acetonitrile, methanol, and water containing 0.1% diethylamine (v/v), at a flow rate of 2.5 ml/min, a column temperature of 22degreesC, and UV detection at 250 nm. The TLC determinations were similarly made using Merck NH2 F-254S precoated glass plates (similar to2 x 5 cm, 5-mum particle size, 0.2-mm layer thickness) with mixtures of acetonitrile, methanol, and water containing 0.1% diethylamine (v/v). Preexisting traces of carcinogenic nitrosamines were detected in some samples of diazeniumdiolates. The methods provide a more efficient means of characterizing the purity of diazeniumdiolate samples prepared for use in biomedical applications than older procedures which rely on differential absorbance measurements at 250 and 350 nm, respectively. (C) 2002 Elsevier Science.

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