A new strategy for fast chiral screening by combining HPLC-DAD with a multivariate curve resolution-alternating least squares algorithm

A strategy aimed at developing faster chiral screening approaches is proposed in this paper by mixing samples and simultaneously screening the resulting mixture of racemates. The data matrix of the mixture obtained by diode array detector or mass spectrometry is deconvoluted into resolved chromatograms and spectra through a multivariate curve resolution-alternating least squares algorithm. The individual racemates are then identified through the resolved UV spectra, and enantiomeric excess ratios can be measured via the resolved chromatograms. Two representative experiments were carried out to verify the feasibility of the strategy. A mixture containing five pairs of racemic solutes was successfully screened on Chiralcel OD column in one-fifth of the conventional analysis time. Another mixture containing 10 racemates gained nine-tenths of the original screening time on three CSPs with a predictive accuracy above 90 %.