3,5-二硝基水杨酸比色法测定芒果的可溶性糖含量

Determination of soluble sugar content in Mangifera indica Linn. by 3,5-dinitrosalicylic acid colorimetry

目的 建立3,5-二硝基水杨酸(3,5-dinitrosalicylic acid,DNS)比色法测定芒果可溶性糖含量的分析方法。方法 首先优化不同配方DNS显色剂测定芒果可溶性糖的条件,再以高效液相色谱法(high performance liquid chromatography, HPLC)检测结果作为参考,筛选建立测定芒果可溶性糖含量的最佳DNS试剂和方法。结果 DNS2试剂在优化条件下的测定结果与HPLC检测结果最为接近,平均相对偏差为8.81%,为芒果可溶性糖含量测定的最佳显色剂。优化的测定条件为:最适检测波长530 nm、显色剂添加量6 mL、显色温度80℃以上、显色时间5min,冷水阻断反应,显色后10min内检测。该方法的平均回收率为94.4%~101.0%,相对标准偏差(relative standard deviations, RSDs)为2.71%~4.83%。结论 基于DNS2试剂的比色法具有较高的准确度和精密度,可作为芒果可溶性糖含量快速测定的方法。

Objective To establish a method for the determination of soluble sugar content in Mangifera indica Linn. based on 3,5-dinitrosalicylic acid(DNS) colorimetry. Methods Firstly, the conditions for the determination of soluble sugar in Mangifera indica Linn. with different formulations of DNS developer were optimized, and then the best DNS reagent and method for the determination of soluble sugar in Mangifera indica Linn. were screened and established with the detection results of high performance liquid chromatography(HPLC) as a reference. Results The soluble sugar content tested by DNS2 reagent under optimized conditions was most similar to those of HPLC,with an average relative deviation of 8.81%, which mean the DNS2 was the best chromogenic agent. The optimized conditions for determination of soluble sugar content in Mangifera indica Linn. were as follows: The optimal detection wavelength was 530 nm, the additive volume of chromogenic agent was 6 mL, the heating temperature was above 80 ℃, and the chromogenic time was 5 min, after blocking the reaction by cold water, the detection should be performed within 10 min. The average recoveries of this method were 94.4%-101.0% with relative standard deviations(RSDs) of 2.71%-4.83%. Conclusion The colorimetric method based on DNS2 reagent has high accuracy and precision, and can be used for the rapid determination of soluble sugar content in Mangifera indica Linn..