Enantiomeric Separation of Free l- and d-Amino Acids in Hydrolyzed Protein Fertilizers by Capillary Electrophoresis Tandem Mass Spectromet

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• 作者：Laura S谩nchez-Hern谩ndez ; Nuria Sierras Serra ; Mar铆a Luisa Marina ; Antonio L. Crego
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2013
• 出版时间：May 29, 2013
• 年：2013
• 卷：61
• 期：21
• 页码：5022-5030
• 全文大小：361K
• 年卷期：v.61,no.21(May 29, 2013)
• ISSN：1520-5118

文摘

Two capillary electrophoresis鈥搕andem mass spectrometry (CE鈥揗S²) methods were optimized in this work using cyclodextrins (CDs) as chiral selectors in order to determine the degree of racemization of the free amino acids contained in different hydrolyzed protein fertilizers used as plant biostimulants. The methodologies developed were characterized by the specificity of MS² experiments enabling the identification of all protein amino acids, except for cysteine. The enantiomeric separation of up to 14 amino acids was achieved with resolutions above 1.0 and limits of detection between 0.02 and 0.8 渭M. The methods were applied to the analysis of complex samples such as hydrolyzed protein fertilizers to evaluate the presence of d-amino acids after different kinds of hydrolysis treatments. The results corroborated the absence or almost negligible presence of enantiomeric conversions of the l-amino acids into d-amino acids in the case of fertilizers obtained by enzymatic hydrolysis, as well as the high racemization rate for those obtained through a chemical hydrolysis.

Keywords:

amino acids; biostimulants; chemical hydrolysis; chiral separation; cyclodextrins; enzymatic hydrolysis; fertilizers; racemization degree