3,5-二硝基水杨酸比色法测定木糖含量的研究

Study on measuring xylose content by DNS reagent

针对3,5-二硝基水杨酸(DNS)比色法测定木糖含量的吸收光谱及其对测定值可靠性的影响因素进行研究。找到了分析木糖的最佳条件为最大吸收波长为490 nm,显色剂用量为3 mL,在沸水浴的显色时间范围为10～15 min,加标回收率为98.4%～101%,重现性好,RSD为7.2×10-3%(n=6)。由于该方法具有方便、安全、成本低等优点,适合于常规实验室木糖批量和定量的测定。

3,5-dinitrosalicylica cid（DNS）method was used to analyze the content of xylose by using spectrophotometry, and the wave-length and some relevant factors were researched in analyzing the content of xylose with DNS method. The best conditions for analyzing the content of xylose had been established. These were： wave-length 490 nm; DNS solution 3 mL; and duration for color development in water bath：10~15 min. The recovery of the procedure was 98.4%~101% and RSD was 7.2×10^-3%（n=6）. The sensitivity of the method had been improved. The experiment had confirmed that the improved DNS method was simple, safe and easy to conduct. The method can be used in common laboratories for quantitative analysis.