惰气熔融-热导法测定氮化铬铁中氮

研究了用氧氮分析仪测定氮化铬铁中氮的最佳工作条件,并重点对方法的准确性进行了讨论。利用氮化硅粉和氮化锰铁两种高氮标样分别建立了两条校正曲线,结果表明两条校正曲线间存在较大的系统误差。用测定硝酸盐基准试剂中氮量对两条校正曲线的准确性进行了验证,结果表明氮化硅粉校正曲线的准确度较高,硝酸银和硝酸钾中氮的回收率分别达到99%、98%,而用氮化锰铁校正曲线计算得到的回收率仅为94%。采用惰气熔融-热导法测定样品,方法的相对标准偏差为0.17%~0.45%,分析结果与蒸馏滴定法测定结果一致。

Determination of nitrogen in ferrochrome nitride by inert gas fusion-thermal conductivity method

The optimal conditions for the determination of nitrogen in ferrochrome nitride by oxygen-nitrogen analyzer were studied. The accuracy of this method was discussed. Two calibration curves were plotted by two high nitrogen standard samples (silicon nitride powder and ferro manganese ni-tride). The results indicated that there was great system error between the two calibration curves. The accuracy of these two calibration curves were verified by nitrogen in nitrate standard reagents.The results showed that the calibration curve plotted by silicon nitride powder were of relatively high accuracy. The recovery rates of nitrogen in silver nitrate and potassium nitrate were up to 99 % and 98 %, respectively. However, the recovery rate obtained from the calibration curve plotted by ferro manganese nitride was only 94 %. The samples were determined by inert gas fusion-thermal conduc-tivity method. The relative standard deviation (RSD) of method was 0. 17 %-0.45 %. The analyti-cal results were consistent with those obtained by chemical distillation method.