Analyses of Drugs and Chemicals by Infrared Absorption Spectroscopy. XIV. : Determination of L-Leucine and L-Isoleucine in Mixture with Suspension Technique

Abstract

A simple infrared spectrophotometric method is offered for determination of L-leucine and L-isoleucine in a mixture with suspension technique by the use of aluminum stearate as a dispersion material in carbon disulfide. The spectra of the optically active (L) compound and the racemic (DL) compound are identical in aqueous solution, but different in these suspensions. Therefore, this technique is available for the determination of optically active compounds. The key bands used for L-leucine and L-isoleucine are respectively 832 and 710 cm^-3 in suspension, and two compounds are easily determined by the use of suitable base lines. This method gave good results in some standard mixed samples.