Determination of glucose concentration in aqueous solution using FT NIR spectroscopy

Abstract

NIR spectroscopy is widely used due to its capability to measure a large number of solid and liquid samples, including water-soluble constituents. The measurements of glucose concentrations in aqueous solutions are useful to examine how low concentrations of glucose in water can be measured using near-infrared spectroscopy and its potential applications for non-invasive measurements of glucose level in the blood. This paper describes an alternative approach to the determination of glucose content in aqueous solutions below 1000 mg/dL using Fourier transform near-infrared spectroscopy. This technique has the advantage of being less intensive sample preparation and non-destructive. Glucose in aqueous solutions were carefully prepared with concentrations of 0 - 100 mg/dL at intervals of 5 mg/dL, 110 - 500 mg/dL at intervals of 10 mg/dL and 525 - 1000 mg/dL at intervals of 25 mg/dL. Thus, the total produces 81 samples of standard solutions for both calibration and validation sample sets. PLSR analysis to near-infrared spectra show that glucose content in aqueous solutions can be predicted accurately with a maximum deviation of 6 mg/dL, indicating that the near-infrared prediction model is sufficient to determine glucose content in the aqueous solutions below 1000 mg/dL. The ability of the NIR to detect glucose content below 1000 mg/dL is particularly important when designing a non-destructive glucose level measuring device using a near-infrared light source.