Determination of enantiomeric compositions of ibuprofen by infrared spectrometry with catalytic amount of simple chiral recognization reagent

Catalytic amount of cheap chiral recognization reagent (quinine) combined with chemometric and infrared spectroscopy (IR) is used for quickly and accurately determining the enantiomeric compositions of ibuprofen. First of all, full spectrum was used as input variable of partial least regression (PLS) to establish calibration model, good prediction rate of average error of 4.65% is obtained. Then, wavelet transform (WT) algorithm with strong compression ability is employed to get more concise model. The low-frequency coefficients are extracted by the simplest Harr wavelet function, and the as input variables to establish the calibration, and good prediction rate of average error of 3.60% is obtained. All the results show that the combination of partial least squares and infrared spectroscopy can be used for quickly and accurately predict the enantiomeric excess (ee) value of ibuprofen.