植物全氮的AA3型流动分析仪测定方法研究

The Determination of Total Kjeldahl Nitrogen in Plants by AA3 Flow Analyzer

为了验证AA3流动分析仪测定植物中总凯氏氮的可行性，对不同硫酸浓度样品所用缓冲试剂中NaOH用量进行了筛选，将结果与常规的植物中总凯氏氮测定方法（FIAstar5000流动分析仪）所测结果进行比较，并考察其测定结果的准确性及稳定性。结果表明：与FIAstar5000法相比，利用AA3流动分析仪测定植物的全氮含量结果无显著差异；采用0.10mL/min进样管时，其检测范围为0~70mg/L；采用0.23mL/min进样管时，其检测范围为0~50mg/L；标准曲线相关系数达0.999以上，平均回收率为97.10%~105.30%，检出限为0.07~0.08mg/L。这表明AA3测定植物全氮的方法准确，可靠，可以推广使用。

Total Kjeldahl nitrogen in plants was determined by the AA3 flow analyzer, the NaOH weight of the buffer in different aciditysamples, and linear range, repeatability, precision, recovery rate and the detection limit were investigated. Compared with the analysisresults measured by AA3 and FIAstar 5000, the results were consistent. Using 0.10 and 0.23 mL/min sample tube, the detection range was0-70 and 0-50 mg/L respectively. The correlation coefficient of the standard curve was more than 0.999, the average recovery rate was97.10%-105.30%, and the detection limit was 0.07-0.08 mg/L. The results showed that the method was accuracy and could be widelyused.