TITLE:
Terahertz Time-Domain Spectroscopy to Identify and Evaluate Anomer in Lactose
AUTHORS:
Satoshi Yamauchi, Sakura Hatakeyam, Yoh Imai, Masayoshi Tonouchi
KEYWORDS:
THz-TDS; Lactose-Powder; Anomer; α-Lactose; β-Lactose
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.4 No.12,
December
16,
2013
ABSTRACT: Lactose powder consisting of α-D-lactose monohydrate and anhydrous β-D-lactose was nondestructively and quantitatively evaluated by
transmission-type Terahertz time-domain spectroscopy (THz-TDS). An absorption
with peak at 39.7 cm-1 (1.19 THz) was assigned to be derived from
anhydrous β-D-lactose, in addition to
the absorptions due to α-D-lactose
monohydrate with peak at 17.1 cm-1 (0.53 THz) and 45.6 cm-1 (1.37 THz). After deconvolution of the spectra using Lorentzian, integrated
intensities of the absorptions with peak at 39.7 cm-1 and 45.6 cm-1 were uniquely dependent on the weight composition ratio of the α-and β-lactose powder. As a
result, the net molar-ratio of the α-and β-lactose in lactose powder could be
precisely evaluated by the integrated intensity ratio. Further, anomer content
in lactose powder extracted from lactose solution was evaluated and the refined
and unrefined features were shown by the evaluation method.