Quantitative Analysis of Lard in Cosmetic Lotion Formulation Using FTIR Spectroscopy and Partial Least Square Calibration

Fourier transform infrared (FTIR) spectroscopy in combination with chemometrics of partial least squares (PLS) has been optimized for rapid determination of lard in a binary mixture with palm oil in a cosmetic lotion formulation. Lard, palm oil, and a binary mixture were extracted from matrix samples using liquid-liquid extraction, evaporated with a vacuum rotary evaporator, and the fat/oil yielded was further subjected to FTIR spectrometric measurement using attenuated total reflectance (ATR) as a sampling handling technique. The level of lard in the mixture with palm oil in the lotion formulation was quantified at frequency region of 1,200-1,000 cm(-1). The PLS calibration model reveals good correlation between the actual value of lard (x-axis) and the FTIR predicted value (y-axis) with a coefficient of determination (R-2) of > 0.99. Furthermore, the classification between lotions with and without lard in their formulation was performed using principal component analysis using the same frequency region used for quantification. The developed method was subsequently used for analysis of cosmetic lotions commercially available in the market. All samples analyzed did not contain lard in their formulations.