Determination of nicotinamide in pre-mixes by near-infrared reflectance spectrometry

Abstract

Nicotinamide has been determined in pre-mixes with vitamin B₁, iron and calcium sulphate by near-infrared (NIR) reflectance spectrometry at 2138 and 2070 nm. The calibration equation involved the computation of a ratio of the second derivative of log(1/R) at these two wavelengths from the NIR spectrum. The calibration was verified by its performance on independent samples from those used in the calibration when the standard deviation of differences between nicotinamide by mass and by NIR was 0.56 g per 100 g. For commercial samples having a more restricted range and a greater homogeneity, the standard deviation compared with HPLC was 0.18 g per 100 g.