Savitzky-Golay differentiation procedure is a commonly used pre-processing technique in the near-infrared spectroscopy, being implemented in the instrumental or specialized data processing software. However, the spectra can be recorded linearly to the wavelength or energy scale depending on the available instrument, which leads to different derivative curves obtained by the Savitzky-Golay approach. The derivatives of the spectra linear to the wavelength scale tend to attenuate. A modified procedure, which avoids this problem, is described and the aim of this note is to bring this pre-processing alternative to the attention of the near-infrared specialists.
CzarneckiMAMorisawaYFutamiY. Advances in molecular structure and interaction studies using near-infrared spectroscopy. Chem Rev2015; 115: 9707–9744.
2.
O’HaverTCBegleyT. Signal-to-noise ratio in higher order derivative spectrometry. Anal Chem1981; 53: 1876–1878.
3.
SavitzkyAGolayMJE. Smoothing and differentiation of data by simplified least squares procedures. Anal Chem1964; 36: 1627–1639.
4.
SteinierJTermoniaYDeltourJ. Comments on Smoothing and differentiation of data by simplified least square procedure. Anal Chem1972; 44: 1906–1909.
5.
LuoJYingKBaiJ. Savitzky–Golay smoothing and differentiation filter for even number data. Signal Process2005; 85: 1429–1434.
6.
GansPGillJB. Examination of the convolution method for numerical smoothing and differentiation of spectroscopic data in theory and in practice. Appl Spectroscop1983; 37: 515–520.
7.
MaddenHH. Comments on the Savitzky-Golay convolution method for least-squares-fit smoothing and differentiation of digital data. Anal Chem1978; 50: 1383–1386.
8.
Hollas JM. Modern spectroscopy. 4th ed. Chichester, USA: Wiley, 2004, chapter 2, Electromagnetic radiation and its interaction with atoms and molecules, pp. 27–40.
9.
AntonovLStoyanovS. Approach for increased information from the second-derivative spectra in UV-Vis absorption spectroscopy. Appl Spectroscop1993; 47: 1712–1715.
10.
Talsky G. Derivative spectrophotometry. Weinheim, Germany: VCH, 1994.
