Enantiomeric separation of FMOC‐amino acids by nano‐LC and CEC using a new chiral stationary phase, cellulose tris(3‐chloro‐4‐methylphenylcarbamate)

Abstract

A novel polysaccharide-based chiral stationary phase (CSP), cellulose tris(3-chloro-4-methylphenylcarbamate), also known as Sepapak-2 or Lux Cellulose-2, has been evaluated for the enantiomeric separation of FMOC derivatives of amino acids. After mobile-phase optimization in nano liquid chromatography (nano-LC) the column enabled the enantiomeric separation of 19 out of 23 amino acids tested, indicating the high chiral recognition power of this new CSP. Subsequently, a comparison of the driving force employed (pressure or voltage) was carried out comparing nano-LC and CEC under the same conditions. Better peak efficiencies and resolution were observed by using CEC experiments, which enabled the chiral discrimination of 20 out of 23 amino acids tested. Finally, in order to show the potential of this new CSP, the determination of the content and the enantiomeric purity of the non-protein amino acid citrulline in food supplements was performed. For that purpose, the method was optimized, evaluated and applied to different commercial samples.

Capillary electrophoresis determination of non-protein amino acids as quality markers in foods

“…To carry out the enantiomeric determination of citrulline in food supplements, a CEC-UV method was developed using cellulose tris(3-chloro-4-methylphenylcarbamate chiral stationary phase (CSPs) as chiral selector, 9-fluorenylmethoxycarbonylchloride (FMOC) as labeling reagent and 0.5 M ammonium formate as running buffer. The method, which demonstrated to be more efficient in comparison with the developed nano-LC method, gave rise to LODs of 7.5 × 10 −7 M for citrulline and made possible to achieve the enantiomeric determination of nineteen more amino acids (among twenty three amino acids analyzed) [17].…”

“…In general terms, enantioselective separations may be relevant in different food areas in order to propose quality markers to assess food authenticity and to detect adulterations, to evaluate the effects of processing, fermentation, microbiological activity and storage, to analyze chiral metabolites and to investigate health-promoting compounds or evaluate flavor and fragrance aromas [2,3,15,16]. In the specific case of chiral non-protein amino acids, the analysis of their enantiomers in foods is a very useful tool not only to assess food quality and authenticity [17], but also to evaluate processing, manufacturing of food supplements and detect microbiological contaminations [12,18].…”

Enantiomeric separations by means of nano‐LC

“…The effect of the presence of different electron‐donating and electron‐withdrawing groups on polysaccharide derivatives was investigated introducing cellulose tris(3‐chloro‐4‐methylphenylcarbamate) (Sepapak‐2) , which was later proposed for the enantiomeric separation of fluorenylmethyloxycarbonyl derivatives of amino acids in nano‐LC and CEC, and the determination of the content and the enantiomeric purity of the non‐protein amino acid citrulline in food supplements by CEC . Sepapak‐2 has been recently compared with Sepapak‐4 ((cellulose tris(4‐chloro‐3‐methylphenylcarbamate)) for the enantioseparation of 16 pesticides .…”

Recent advances in electrodriven enantioseparations

“…CSPs containing cellulose tris(3‐chloro‐4‐methyl‐phenylcarbamate) and cellulose tris(3‐methyl‐4‐chlorophenylcarbamate) have been compared in nano‐LC and CEC for the enantioseparation of FMOC‐amino acids and pesticides . Both studies employed ammonium formate, pH 2.5/water/ACN as mobile phase.…”