直流辉光放电光谱法同时测定铸铁中12种元素

通过试验确定激发电压为1 150 V,激发电流为45 mA,预燃时间为180 s和积分时间为10 s的分析条件,并对各元素光电倍增管电压进行调节,实现元素含量与激发强度有最佳输出关系。建立了同时测定铸铁中碳、硅、锰、磷、硫、镍、铬、钼、铜、钛、钒、硼含量测定的直流辉光放电光谱法。采用基体元素铁为内标,选择6块白口合金铸铁光谱标准样品,以各分析元素对基体的相对含量和相对强度绘制校准曲线,各元素校准曲线的相关系数均在0.994 0以上。精密度考察结果表明,各元素测定结果的相对标准偏差在0.24%～2.5%之间。对灰口铸铁标准样品进行测定,测定值与认定值相符。对白口铸铁样品与火花源原子发射光谱比对分析,结果基本一致。

Simultaneous determination of twelve elements in cast iron by direct current glow discharge optical emission spectrometry

The following analytical conditions were obtained by experiments: the excitation voltage was 1 150 V, the excitation current was 45 mA, the pre-combustion time was 180 s and the integral time was 10 s. Moreover, the photomultiplier voltage of elements was adjusted, realizing the optimal output relationship between elemental content and excitation intensity. The simultaneous determination method of twelve elements in cast iron (including carbon, silicon, manganese, phosphorus, sulfur, nickel, chromium, molybdenum, copper, titanium, vanadium and boron) by direct current glow discharge optical emission spectrometry was established. The matrix iron element was used as internal standard. Six standard samples of alloyed white cast iron for spectral analysis were used to prepare calibration curves based on the relative content and intensity of analytical element to matrix. The correlation coefficients for all elements were higher than 0.994 0. The precision test results indicated that the relative standard deviations (RSD) were between 0.24% and 2.5%. The certified reference materials of grey cast iron were determined according to the proposed method, and the found results were consistent with the certified values. The analysis of white cast iron samples was compared with the spark source atomic emission spectrometry, and the results were consistent.