Determination of low concentration glucose solution using Raman spectroscopy based on the internal standard method

Glucose is an essential substance for life and exists in a cyclic equilibrium in solution. Raman spectroscopy is utilized to differentiate substances based on their glucose concentration. This study employed solid-state density functional theory to simulate the Raman spectra of D(+)-glucose, D-glucose monohydrate, and two types of glucopyranose. Experimental spectra were obtained for D-glucose monohydrate and solutions of varying concentrations. The calculation results of various glucose configuration theories indicate that 1125 cm⁻¹ is the characteristic peak of glucose. This finding aligns with the experimental results and literature presented in this article, addressing concerns regarding the validity of glucose characteristic peaks.

The peak at 1640 cm⁻¹, attributed to water, serves as the normalized internal standard. The correlation coefficients obtained from linear regression analysis were all greater than 0.990, with limits of detection (LOD) of 48.1 mg/dL and 40.3 mg/dL, respectively. The minimum detectable concentration (MDC) for qualitative analysis is 12.5 mg/dL. The relative area method has been demonstrated to be a direct and effective approach for accurately quantifying low-concentration glucose solutions.