2. Experiment and methods
2.1. Reagents and instruments
Branded powdered milk was purchased from the market . Test objects including lactose, ZnSO4, and melamine
were obtained from Sinopham Chemical Reagent Co., Ltd.
An electronic analytical balance oscillator
and an electrical thermal vacuum drying oven
were used for sample
preparation. The spectra of pure materials were collected using
Spectrum One NTS . The samples were analysed
in an NIR line mapping system . The spectra were obtained