FT-NIR COMPARATIVE QUANTITATIVE PERFORMANCE FOR COMPLEX SAMPLES

Quantification in routine near IR spectroscopy is based on mA differen ces requiring signal conservation and limitation of instrument noise t o a few mu A units. An FT-NIR bench equipped with a fiber optic sampli ng probe was used for quantitative analysis of clear liquid chemical m ixtures, emulsions, and homogeneous and heterogeneous granular solids. The combination of hardware, sampling optics, and calibration equatio n produced analytical standard errors comparable to those obtained wit h both dispersive and acousto-optic NIR instruments. The sampling area of the probe required averaging of multiple probes for heterogeneous solids. Excellent wavelength reproduction of the FT-NIR enabled the us e of spectral subtraction for both qualitative and quantitative purpos es.