DETERMINATION OF L-MENTHOL IN PHARMACEUTICAL PRODUCTS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH POLARIZED PHOTOMETRIC DETECTION

A simple analytical method for l-menthol by high-performance liquid ch romatography with a polarized photometric detector was established. Th e polarized photometric detector was constructed with two polarizers m ounted on both sides of the flow cell in a conventional photometric de tector and can be easily used for the detection of optically active co mpound, such as l-menthol. This study was conducted with a newly devel oped split-cell assembly in order to increase the sensitivity. The cha racteristic of this method is the ability to determine optically activ e compounds selectively among the other coexisting materials and the p retreatment of the sample can be very simple or not required at all. T he detection of l-menthol by this method is 0.5 mu g. A good agreement was shown between another commonly used GC method and the method desc ribed in this paper. (C) 1998 Elsevier Science B.V. All rights reserve d.