Enantiomeric reversed-phase high-performance liquid chromatography resolution of d-/l-penicillamine after spirocyclization with ninhydrin and by using copper(II)-l-proline complex as a chiral selector in the mobile phase

A new HPLC method by fluorescence or UV/vis absorbance detection has been developed for the separation and quantification of penicillamine stereoisomers after their spirocyclization with ninhydrin. The separation was performed on an achiral C18 column by isocratic elution with a copper(II)-l-proline complex as a chiral selector in the mobile phase. The method was able to detect traces of l-penicillamine in samples of d-penicillamine below 0.1% in fairly short times (about 16 min) with a good resolution (Rs = 1.31). On the whole, the method was found to be stable and useful in the quality control of the bulk material and formulations.