基于DNS比色法的土壤蔗糖酶检测条件选择

Soil Sucrase: Detection Conditions Based on DNS Colorimetric

为了准确测定土壤蔗糖酶含量,分析了不同波长、显色剂加入量、甲苯加入量、加热时间、显色稳定时间等条件对3,5-二硝基水杨酸（3,5-dinitrosalicylic acid,DNS）比色法测定土壤蔗糖酶含量的影响。结果表明：当波长为510 nm,显色剂用量为1.5 m L,甲苯加入量0.1 m L,水浴时间5 min,待测液存放时间小于4 h,显色稳定时间在0.5~2 h之间时,标准曲线在0.25~2 mg范围内线性良好（R2=0.9991）,土壤蔗糖酶含量的变异系数（CV）小于9%,回收率在96%~109%范围内,检测结果的精密度和准确性较高。上述检测方法安全、经济、高效,适用于实验室批量土壤的蔗糖酶含量测定。

The aim was to detect the content of soil sucrase precisely. The effect of different wavelengths, theamount of chromogenic agent and toluene, heating time and the stable time of color on the content of soilsucrase detected by 3,5-2 dinitrosalicylic acid（DNS） method was analyzed. The results showed that when thewavelength was 510 nm, the amount of reagent was 1.5 m L, the amount of toluene was 0.1 m L, the time of waterbath was 5 min, storage time of the solution to be determined was less than 4 h, the stable time of color wasbetween 0.5- 2 h, the standard curve in the range of 0.25- 2 mg had good linear relation（R2=0.9991）, thecoefficient of variation（CV） was less than 9%, the recoveries were in the range of 96%- 109%, and theprecision and accuracy of the test results were relatively high. The above method was safe, economical andefficient, and suitable for batch determination of soil sucrase.