Multiple Heart-Cutting Two-Dimensional HPLC-UV Achiral–Chiral Analysis of Branched-Chain Amino Acids in Food Supplements under Environmentally Friendly Conditions

A multiple heart-cutting (mLC-LC) two-dimensional HPLC-UV achiral–chiral method for the direct analysis of branched-chain amino acids (BCAAs) in food supplements under environmentally friendly conditions was developed to cope with very well-known limited chemoselectivity chromatographic media enantioselective analysis. Both achiral and chiral methods were compliance main principles green chromatography. The performed isocratically an optimized ion-pair reversed-phase (IP-RP) based on a water/EtOH (95:5, v/v) mobile phase containing heptafluorobutyric acid (7 mM) as IP agent. characterized by appreciable performance validated before real sample. High recovery values all compounds (from 97% 101%) found interday evaluation. Additionally, low RSD% long-term period measured, range between 1.1% 4.8%. Still, LOQ value 0.06 mg/mL established compounds. quantitative commercial supplement revealed that BCAAs present amounts close those declared producer. carried out through application ligand-exchange chromatography (CLEC) approach, using O-benzyl-(S)-serine ((S)-OBS, 0.5 selector Cu(II) nitrate (0.25 metal source eluent. Resolution separation factor up 2.31 1.43, respectively, obtained. two systems connected six-port switching valve, mLC-LC confirmed absence D-enantiomers supplement, reported manufacturer’s label.