【摘要】 采用微波消解对土壤样品中的氮进行前处理,用纳氏试剂分光光度法测定总氮,发现微波消解最佳条件为:用2 mL浓H2SO4和1 mL HF,于0.2 Mpa下保持3 min,0.5 MPa下保持2 min,0.7 MPa下保持5 min;方法的检出限为0.003 4 mg/L,相对标准偏差RSD为6.7%,加标回收率为85.90%～114.5%,与半微量凯氏定氮法比较的相对误差为-1.16%。说明微波消解法消化土壤样品测定总氮,具有简便、快速、精密度与准确度较高等优点。更多还原

【Abstract】 The nitrogen species in soil is pre-treated with microwave digestion,followed by determination of the total nitrogen with spectrophotometry coupled with Nessler’s Reagent.The result indicates that the optimal experimental conditions are as follows: 2 ml concentrated H2SO4 &1mlHF with the constant 3 min in 0.3 MPa and constant 2 min in 0.5 Mpa and 5min in 0.7 MPa.The method,with 0.003 4 mg/L of detection limit and 6.7% of relative standard deviation and 85.90%～114.5% of recovery of standard addition and –1.16% of relative error compared with National Standard,is available to determination of total nitrogen in soil due to its simplicity,quickness,better precision & accuracy.更多还原