Qualitative and quantitative determination of potassium aluminum sulfate dodecahydrate in potato starch based on terahertz spectroscopy.

Terahertz time‐domain spectroscopy (THz‐TDS) was used to study the additive potassium aluminum sulfate dodecahydrate (PASD) in potato starch. The terahertz time‐domain and frequency domain spectra of potato starch potato starch and PASD were obtained. The absorption coefficient spectrum and refractive index spectrum of the above two substances is calculated. The absorption coefficient spectrum shows that potassium aluminum sulfate dodecahydrate has obvious characteristic absorption peak in terahertz band. THz‐TDS technique can be used to identify the characteristics of potassium aluminum sulfate dodecahydrate in starch. Terahertz time‐domain spectra of potato starch doped with different percentage (mass fraction) potassium aluminum sulfate dodecahydrate were obtained. It was found that with the increase of the content of PASD, the amplitude of the absorption peak decreased and the refractive index decreased gradually, which indicated that THz‐TDS technique could be used for qualitative identification and quantitative detection of PASD in potato starch. [ABSTRACT FROM AUTHOR]