背景扣除光谱干扰-单道扫描电感耦合等离子体原子发射光谱法测定高合金钢中磷

Determination of phosphorus in high alloy steel by sequential inductively coupled plasma atomic emission spectrometry with correction of spectral interference by background correction

利用单道扫描型电感耦合等离子体原子发射光谱仪(ICP-AES)的高分辨率及步进扫描功能,精确定位选择背景扣除点,有效消除了Cu 213.597nm、Fe 213.592nm谱线对P 213.618nm分析谱线的严重尾翼干扰和铬、镍、钼等元素的背景增强影响。对比了P 213.618nm作为分析谱线和充高纯氮气、P 178.229nm作为分析谱线的测定结果,发现采用P 213.618nm作为分析谱线测定结果的精密度更好。按照实验方法测定高合金中磷,无须对铬、镍、钼、铜等元素进行基体匹配,也不必使用干扰因子校正法消除铜的影响,并且使用同条铁基校准曲线,能同时进行低合金钢和高合金钢中微量磷的测定。磷校准曲线的线性相关系数r=0.999 1,方法可以测定高合金钢中质量分数低至0.002%的磷。按照实验方法测定高合金钢标准样品中磷,测定值与认定值一致。测定高合金钢中质量分数为0.006 8%的磷,测定结果的相对标准偏差(RSD,n=10)小于4%。

The high resolution and stepping scan functions of sequential inductively coupled plasma atomic emission spectrometer（ICP-AES）were used for accurate positioning and selection of background correction points.The serious tail interference of Cu 213.597 nm and Fe 213.592 nm lines to P 213.618 nm as well as the background enhancing effect of chromium,nickel and molybdenum were effectively eliminated.The determination results were compared when P 213.618 nm and P 178.229 nm with filling of high-purity nitrogen was used as analytical line,respectively.The results showed that the precision of determination results was better when P 213.618 nm was used as analytical line.The phosphorus in high alloy steel could be determined according to the experimental method without the matrix matching of chromium,nickel,molybdenum and copper.It was also not necessary to correct the influence of copper by interference factor method.The micro phosphorus in low alloy steel and high alloy steel could be simultaneously determined using same iron-based calibration curve.The linearly correlation coefficient of calibration curve of phosphorus was r=0.999 1.The proposed method could be used to determine the phosphorus in high alloy steel with mass fraction low to 0.002%.The content of phosphorus in high alloy steel sample is determined according to the experimental method,and the found results were consistent with the certified values.When the mass fraction of phosphorus in high alloy steel was 0.006 8%,the relative standard deviation（RSD,n=10）of determination results was less than 4%.