Rapid determination of melamine in milk-powder by FT-NIR

Complete text of publication follows. Near infrared spectroscopy is the measurement of the wavelength and intensity of the of near-infrared light by a sample. It is based on molecular overtone and combination vibrations. NIR spectroscopy is typically used for quantitative measurement of organic functional groups, especially O-H, N-H, and C=O. Detection limits are typically 0.1% and applications include pharmaceutical, agricultural, polymer, and clinical analysis. Such transitions are by the of . As a result, the in the near IR region is typically quite small. One advantage is that NIR can typically penetrate much further into a sample than radiation. NIR spectroscopy is therefore not a particularly sensitive technique, but it can be very useful in probing bulk material with little or no sample preparation. The molecular overtone and combination bands seen in the near IR are typically very broad, leading to complex spectra; it can be difficult to assign specific features to specific chemical components. calibration techniques including principal component analysis or partial least squares and development of calibration samples arc essential for NIR analytical methods. In this study, Melamine in milk powder and baby food were investigated using FT-NIR spectrometer. Direct and indirect measurement techniques were carried out using flat bottom glass vials. All samples were grinded. Particle size distribution were seen the same for all samples. Maximum wavelength was found to be 6800 1/cm with pure materials and set to calibration. Different melamine mixtures were prepared and measured using FT-NIR Spectrometer. Spectra were divided into two set which are calibration and validation. Collected data were evaluated using chemometric pretreatments. About 500 spectra were collected for ten different concentration range between 0.1% - 3.0% range. Unknown samples were analyzed with the aid of calibration curve. FT-NIR values were validated with Kjehdahl method results. Result predictions were excellent for and over 0.1% concentration. Under this concentration value, it gave unexpected results. This method is shown as fast, precise, non-destructive for over 0.1% concentration range.