Gioia MG, Cacciari B, Leoni A, Gatti R. 2,7-Dimethyl-3,8-dinitrodipyrazolo[1,5-a:1′,5′-d]pyrazine-4,9-dione: A new labelling reagent for liquid chromatographic analysis of amino acids.
Anal Chim Acta 2006;
579:152-7. [PMID:
17723739 DOI:
10.1016/j.aca.2006.07.035]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 07/10/2006] [Accepted: 07/13/2006] [Indexed: 11/26/2022]
Abstract
The use of 2,7-dimethyl-3,8-dinitrodipyrazolo[1,5-a:1',5'-d]pyrazine-4,9-dione as pre-column reagent for LC analysis of amino acids is proposed. The compound reacts (30 min at 68 degrees C in presence of 0.04 M triethylamine in a dimethylsulfoxide-water mixture) with primary and secondary amino function and the stable resulting adducts can be chromatographed under reversed-phase conditions and detected at lambda=280 nm. The derivatization conditions were optimized by a series of experiments. The effect of temperature, triethylamine concentration and reagent on the reaction was investigated. The yield of the glycine derivative was found to be quantitative at a reagent amino acid molar ratio of about 6 by comparison with an authentic specimen of synthesized glycine adduct. Application of the method to quality control of commercially available oral polyaminoacid formulations is described.
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