
Keywords: (l)-PCA, l-pidolic acid; (d)-PCA, d-pidolic acid; PCA, pidolic acid; (l)-PGA, l-pyroglutamic acid; (d)-PGA, d-pyroglutamic acid; PGA, pyroglutamic acid; TFAA, trifluoroacetic anhydride; HCl-IPA, hydrochloride 2-propanol solution; CPF, chiral purity factor