紫外分光光度法测定土壤过氧化氢酶活性

Measurement of Catalase Activity in Soil by Ultraviolet Spectrophotometry

土壤过氧化氢酶是土壤中非常重要酶类,为了探索一种测定土壤过氧化氢酶活性的简单、可靠而适用的测定方法,我们进行了利用紫外分光光度法测定土壤过氧化氢酶活性的方法研究。结果表明,紫外分光光度法重现性优于高锰酸钾容量法,溶液在240nm处的吸光度可以稳定11小时以上,对4种土壤分析表明,紫外分光光度法的测定结果与高锰酸钾容量法之间无显著差异。传统高锰酸钾容量法加酸后再过滤容易导致溶液有颜色,过滤液易浑浊,过滤时间长。本试验表明,在过滤前加入饱和铝钾矾,然后直接将溶液过滤到盛有酸的容器内,既可以使溶液无色,又能使溶液澄清透明,还能使过滤速度大为加快。总之紫外分光光度法重现性好、稳定时间长,操作简单,不需要特殊试剂,避免了容量法的滴定误差,是一种值得推广普及的测定土壤过氧化氢酶活性的好方法。

Catalase is an important enzyme in soil.In order to find a simple,reliable and applicable method to measure the activity of soil catalase,the experiment to determine the catalase activity in soil by ultraviolet spectrophotometry was conducted.The results showed that the reproducibility of ultraviolet spectrophotometry was better than potassium permanganate volumetric method.The absorbency of solution of soil extract in 240 nm had no visible changes after stored 11 h.The results from 4 soils indicated that there was no significant difference between ultraviolet spectrophotometry and potassium permanganate volumetric method.The addition of sulfate acid before filtration in traditional volumetric method led to a colored and turbid solution,and long filtration time.The color and turbidity in soil extract was disadvantage to measure the absorbency.Adding alum saturated solution before filtration and then filtrating in a utensil with 5 ml sulfate acid（1.5 mol L-1） could gain a colorless and transparent soil extract and shorten the filtrating time.In conclusion,with high reproducibility and stability,simple operation,no special reagent and avoidance of the error in titrimetry,ultraviolet spectrophotometry was a valuable method and worth of popularization in determination of soil catalase activity.