Determination of enantiomeric compositions of ibuprofen by
infrared spectrometry with catalytic amount of simple chiral
Xiangou Zhu1,2 and Jun Jiang1,2*
of Chemistry and Materials Engineering, Wenzhou University,
Chashan University Town, Wenzhou, Zhejiang Province 325035,
People’s Republic of China.
2College of Physics and Electronic Engineering
Information, Wenzhou University, Chashan University Town,
Wenzhou, Zhejiang Province 325035, People’s Republic of
*Corresponding author. E-mail:
Tel: +86 577 88368280.
Fax: +86 577 88368280.
Accepted 13 May, 2011
Catalytic amount of cheap chiral recognition
reagent (quinine) combined with chemometric and
infrared spectroscopy (IR) was used for quick
and accurate determination of the enantiomeric
compositions of ibuprofen. First of all, full
spectrum was used as the input variable of
partial least regression (PLS) to establish the
calibration model, after which a good prediction
rate of the average error of 4.65% was obtained.
Then, wavelet transform (WT) algorithm, with
strong compression ability, was employed to
obtain a more concise model. The low-frequency
coefficients were extracted by the simplest Harr
wavelet function, and were used as the input
variables to establish the calibration, after
which a good prediction rate of the average
error of 3.60% was obtained. All the results
showed that the combination of partial least
squares and infrared spectroscopy can be used
for quick and accurate prediction of the
enantiomeric excess (ee) value of ibuprofen.
Ibuprofen, enantiomeric compositions, quinine, infrared, wavelet