Simultaneous RP-HPLC-DAD determination of dansyl amino acids in chemically treated human hair

Abstract

A simple, rapid and reliable RP-HPLC-DAD method for the analysis of 19 amino acids in the protein hydrolysate of chemically treated hair is developed. The pre-column dansylation and RP-HPLC separation were optimized and peak resolution was improved as compared to previously published HPLC methods. The developed method showed excellent linearity for all tested amino acids in the concentration range 0.05-0.5 mmol/l. The obtained results show that the concentration of all amino acids detected in bleached hair decreases with increasing the concentration of hydrogen peroxide, this is most significant for cystine, compared to virgin hair. Higher amounts of the typical amino acids for keratin have been measured after exposure of hair to protein treatments. The method has been shown as very useful for amino acids analysis in a protein hydrolisate and it can be also used for establishing the amino acid profiles of other protein samples using this optimized procedure.

Metabolic Engineering of Pediococcus acidilactici BD16 for Heterologous Expression of Synthetic alaD Gene Cassette and L-Alanine Production in the Recombinant Strain Using Fed-Batch Fermentation

“…Samples were then injected into the HPLC system and quantification was performed at 250 nm. The spectral peaks obtained at a specific retention time in the case of standard L-alanine and microbial L-alanine produced were later compared for confirmation purposes [33].…”

4-Chloro-7-Nitrobenzofurazan (Nbd-Cl) as Pre and Post-Column Derivatization Reagent for Amine Groups Analysis Using Chromatography: A Mini-Review

“…Analysis of several compounds require a derivatization step to increase the detection limits. Several derivatization reagents for amine groups such as ninhydrin [2], 2,4-dinitro-1-fluorobenzene [3], ophthalaldehyde (OPA) [4], 1,2-naphtoquinone-4-sulfonate (NQS) [5], Sanger regent (FNDB) [6], fluorescamine [7], 5-(dimethylamino)naphthalene-1-sulfonyl chloride (Dansyl Cl) [8], and 4-Chloro-7-nitrobenzofurazan (NBD-Cl) [9]. NBD-Cl is quite popular because it has high sensitivity and can be used when analyzing low-concentration samples.…”