The DNA triplet GCA is successfully used for the first time as a chiral selector for the chiral
discrimination and optical purity measurement of some α-amino acids by investigating the
collision-induced dissociation spectra of the sodiated ternary complex ion formed by
electrospray ionization.

The DNA triplet GCA is successfully used as a chiral selector for the chiral discrimination of
amino acids using amino acids themselves as a co‐selector. Chiral discrimination was
achieved by investigating the collision‐induced dissociation spectra of the [XA+ XR+ 2Y−
2H] 2− ion generated by electrospraying a mixture of analyte amino acid (XA), reference
amino acid (XR) and GCA (Y). The relative abundances of fragment ions resulting from the
competitive loss of reference and XA's are considered for measuring the degree of chiral …