A Simple Lab on Chip for Quantitation of Sugar Content in A Syrup Sample

Original Paper

Abstract

A simple lab on chip (LOC) for quantitation of sugar contents was proposed. It is based on migration of sucrose solution along a channel filled with water. The migration time, which is the time period that the sample travels, starting from at the injection moment to the point of detection, is related to the sugar content. By taking the benefits due to the Schlieren effect, the migration time can be monitored by using a fiber optic spectrophotometer. In another simple LOC system, addition of a bromothymol blue indicator in the water channel, the migration time was be able to be monitored via naked eyes and with a stop watch. Calibration equations were : y = 0.430 x + 9.500, R2 = 0.957 (for 800nm), and y = 1.12 x + 43.33, R2 = 0.993 for the LOC with fiber optic spectrophotometer and for the LOC with naked eyes detection, respectively. The results obtained by the proposed methods for determination of sugar contents in concentrates of syrup samples and samples of pharmaceutical preparations for cough syrup, agree with that using a refractometer which is normally used. This is an approach for green analytical chemistry.