采用自行研制的两组流动比色装置,分别安装在检测器的样品光束和参比光束位置,提出了一种改进的流动注射微分分光光度测定南瓜提取物总糖含量的方法.一次进样同时产生6个拐点的微分吸收曲线(A1、A2、A3、A4、A5、A6).根据各拐点所测得的响应信号值,求得糖的质量浓度在0.3~46 mg·L-1范围内呈线性关系.为检测方法的精密度和回收率分析了3个已知样品并加入11 mg·L-1糖标准溶液,测得方法的相对标准偏差(n=5)在0.6%~1.3%之间,回收率在98.7%~101.2%之间.

Manifold of a FI-spectrophotometric installation for determination of total saccharides in pumpkin was designed and fabricated.Two sets of self-made flow-cells were installed separately in the light paths of sample and blank (or reference) solution.As shown in the figure,6 inflection points (A1,A2,A3,A4,A5 and A6) were observed in the differential absorption curve at one sample introduction.Based on the response signals at the inflection points,linear relationships between values of ΔAT and concentration of total saccharides was obtained in the range of 0.3-46 mg·L-1.Tests for precision and recovery were made on analysis of 3 samples of known contents of total saccharides and of addition of 11 mg·L-1 of standard saccharide solutions,values of RSD′s (n=5) found were ranged from 0.6% to 1.3%,and values of recovery in the range of 98.7%-101.2% were obtained.