TTC法测定水稻土泥浆中脱氢酶活性的影响因素

以厌氧水稻土泥浆为供试材料,采用不同质量浓度2,3,5-氯化三苯基四氮唑(TTC)、反应时间、萃取剂及测定波长等条件,对影响水稻土泥浆中脱氢酶活性测定的因素进行探讨。结果表明,10g/L TTC的灵敏度最高,10～20g/L可作为测定水稻土泥浆中脱氢酶活性的适宜质量浓度;相应的脱氢酶活性在0.25h时最高,并随着反应时间的延长而逐渐降低。乙醇和丙酮对三苯基甲臜(TF)的萃取效果优于甲醇和甲苯,且0.2h为最佳的萃取时间。通过比较标准体系和泥浆体系的差异,TF的最佳吸收峰为480nm。测定土壤泥浆脱氢酶的最佳条件为10g/L TTC,恒温水浴反应0.25h,乙醇萃取0.2h,在480nm下比色测定TF的生成量。

Study on Influencing Factors for TTC dehydrogenase Activity Measurement in Slurry of Paddy Soil

The paper took anaerobic paddy soil slurry as tested materials,and discussed what reaction factors coule influence the determination of dehydrogenase activity,such as the concentration of TTC,reaction time,the selection of different extractant,determination wavelength and so on.The result showed the highest sencitivity presented at 10 g/L,and 10 to 20 g/L TTC could be used as a suitable concentration range to measure dehydrogenase activity.Moreover,the dehydrogenase activity got to the summit at 0.25 h,then it decreased with the extend of reaction time.In addition,as to the extract effect of TF,ethanol and acetone were superior to methanol and toluene,meanwhile,0.2 h was the optimal extract time.According to comparing the differences between normal system and slurry system,the optimal absoprtion peak of TF was 480 nm.In brief,the best choice of reaction factors used to determine the dehydrogenase activity of paddy soil slurry as follow: TTC concentration was 10 g/L,water reaction time was 0.25 h at an even temperature,then using ethanol extracted 0.2 h,and measuring the amount of TF at 480 nm wavelength.