A Determination System of Glucose Aqueous Solutio n Based on Near Infrared LED

Glucose plays an important role in the field of biology because it is the main source of energy for life activities. Detection of its concentration is widely used in food industry and environmental monitoring. Compared with other methods, the near infrared (NIR) absorption method has better flexibility, which can be used to measure the concentration of glucose solution under different concentrations and different precision. An NIR light-emitting diode (LED) is used as light source and linear decrease of total transmission light intensity is found as the concentration of glucose aqueous solution increases in this work. Since the effect of temperature change on the absorption spectrum of water is far greater than the effect of glucose concentration on the absorption spectrum of the solution, a thermostatic circulation system is designed to control the sample temperature. Measures to improve the stability of the light source system were explored, which reached the stability of 0.3 % per hour. The method proposed in this paper is instructive for the determination of high concentration of glucose solution.