Multicommutated flow system for the determination of glucose in honey with immobilized glucose oxidase reactor and spectrophotometric detection

A new automated method for the determination of glucose in honey is proposed. The method is based on multicommutated flow analysis (MCFA) and employs an immobilized glucose oxidase reactor and spectrophotometric detection at 505 nm of the red quinoneimine formed (Trinder's method). The calibration curve obeyed a second order equation in the range 0-0.14 gL(-1) (h=-2.2199 C-2 + 1.3741 C + 0.0077, r(2) = 0.9991, where h is the peak height (absorbance) and C the concentration in g L-1). The method was validated analyzing eight commercial samples, both by the AOAC 954.11 and 977.20 official methods. According to Student's t-test of mean values, at the confidence level of 95% the results obtained with the proposed method were in agreement with those obtained by the official methods. Precision (Sr(%), n = 10) was 3% and the sampling frequency of the system was 20 samples h(-1). (C) 2008 Elsevier B.V. All rights reserved.