separation of the racemic mixture of carvone using drift gas modifier by ion mobility spectrometry

Ion mobility spectrometry (ims) is an analytical technique that can separate gas-phase ions at atmospheric pressure. to this end, isomer separation (for structural and optical isomers) is a main advantage of ims, while mass spectrometry fails for it. enantiomer mixtures have similar physicochemical properties while they have different metabolic properties, so their separation is very important for their analysis. here, the racemic mixture of carvone was separated by a drift gas modifier for qualitative and quantitative analysis using ims [1,2]. tert-butanol was selected as the modifier gas to separate the enantiomers mixture, and some effective parameters, such as flow rate of drift and modifier gas, and cell temperature were optimized. these parameters affect the ion cluster formation and collision cross-sections, influencing on the resolution between ims isomers ion peaks. at the optimum condition, high resolution between r and s enantiomer of carvone was observed with a time difference of about 2 ms. the calibration curves were plotted using their standard solutions, and the linear dynamic ranges were obtained 50-500 mg. l-1 for both isomers.