纳氏试剂比色法测定土壤铵态氮的研究

Measurement of NH3-N in Soil with Nessler's Reagent Colorimetry

进行了用纳氏试剂比色法测定土壤中铵态氮的实验。试验表明,入射光波长在390±10nm范围内,方法的灵敏度较高;用酒石酸钾钠-氢氧化钠溶液作为掩蔽剂,可排除土壤中钙、镁等金属离子对测定的干扰。并且对氢氧化钠用量、显色剂用量进行试验,以用20%氢氧化钠溶液1.5mL,纳氏试剂0.5mL为适宜测定条件。方法检出限为0.049mg/L,定量下限为0.098mg/L。

Experiment was done to detect NH3-N in soil by Nessler's reagent colorimetry. Results showed delicacy of the method was improved when wavelength of the incidence was between 390mn and 410nm. Sodium potassium tartrate - NaOH solution was used as masking agent to reject the disturbance of Ca2+ and Mg2+. The dosage of NaOH solution and Nessler's reagent was tested. Results indicated that the appropriate dosage of NaOH solution was 1.5ml and Nessler's reagent was 0.5ml. The detection limit was 0.049mg/L and quantitative lower limit was 0.098mg/L.