A portable mid-infrared spectrometer and a non-targeted chemometric approach for the rapid screening of economically motivated adulteration of milk powder

A portable, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) device in conjunction with chemometrics was evaluated as rapid screening tools for the non-targeted detection of milk powder (MP) adulteration using melamine (MEL) as a surrogate contaminant. A single-class soft independent modeling of class analogy (SIMCA) model was developed for each of two spectral ranges using a diverse set of MPs and applied to the classification of both wet-blended (WB) and dry-blended (DB) MEL and a set of MP control test samples. Satisfactory prediction of economically motivated (EM) concentrations of MP adulteration was obtained along with 100% correct classification rates for concentrations as low as ≥0.30% for WB and ≥1.0% for DB MEL test samples. This portable infrared device in conjunction with SIMCA classification is potentially an ideal screening tool for the rapid and routine non-targeted assessment of economically motivated adulteration (EMA) of milk powder.