电感耦合等离子体原子发射光谱法测定锰铁合金、锰硅合金和金属锰中8种微量元素

锰铁合金、锰硅合金、金属锰中铅、砷、钛、铜、镍、钙、镁、铝的含量决定了产品质量,以往常采用化学法或原子吸收光谱法进行测定,但存在准确度较差或测定速度不能满足要求等问题。为了实现上述元素的准确、快速测定,建立了采用电感耦合等离子体原子发射光谱法(ICP-AES)测定锰铁合金、锰硅合金和金属锰中微量铅、砷、钛、铜、镍、钙、镁、铝的方法。实验以硝酸、盐酸、氢氟酸、高氯酸分解样品,并使硅与氢氟酸反应生成四氟化硅挥发除去,试液中剩余共存元素主要有铁、锰等。实验结果表明,铁不干扰测定,通过在标准溶液系列中进行锰基体匹配消除锰基体效应的影响。以2mL高氯酸和6mL盐酸混合酸(8%)作为分析介质,可以达到最佳分析效果。在各元素校准曲线线性范围内,线性相关系数在0.9992~0.9999之间;方法中各元素的检出限在0.0001~0.0040μg/mL。实验方法用于测定锰铁合金、锰硅合金、金属锰中铅、砷、钛、铜、镍、钙、镁、铝,结果的相对标准偏差(RSD,n=11)在2.2%~9.4%;回收率在95%~105%;选择7个实验室进行了验证试验,各实验室间结果基本一致;按照实验方法测定了4个标准样品(材字-32、YSB C 28618、YSB C 26605)中铅、砷、钛、铜、镍、钙、镁、铝,结果与认定值相吻合。

Determination of eight microelements in ferromanganese alloy,ferromanganese-silicon alloy and manganese metal byinductively coupled plasma atomic emission spectrometry

The content of lead, arsenic, titanium, copper, nickel, calcium, magnesium and aluminum in ferromanganese alloy, manganese-silicon alloy and manganese metal determined the quality of products. In the past, their contents were usually measured using chemical method or atomic absorption method, which had some problems such as poor accuracy or slow measurement speed that could not meet the requirements. In order to realize the accurate and rapid determination of above elements, the inductively coupled plasma atomic emission spectrometry (ICP-AES) was employed to measure the contents of trace lead, arsenic, titanium, copper, nickel, calcium, magnesium and aluminum in ferromanganese alloy, manganese-silicon alloy and manganese metal. The samples were decomposed with nitric acid, hydrochloric acid, hydrofluoric acid and perchloric acid. The silicon in sample reacted with hydrofluoric acid to form SiF₄ and then be removed by volatilization. The residual coexisting elements in sample solution mainly included iron and manganese. The experimental results showed that the iron had no interference with the determination. The matrix effect of manganese was eliminated by matrix matching in the standard solution series. The mixed acid (8%) of 2mL perchloric acid and 6mL hydrochloric acid was used as medium to achieve the best analysis results. Within linear range of calibration curves of elements, the correlation coefficients ranged from 0.9992 to 0.9999. The detection limit of elements in this method was 0.0001-0.0040μg/mL. The proposed method was applied for the determination of lead, arsenic, titanium, copper, nickel, calcium, magnesium and aluminum in ferromanganese alloy, manganese-silicon alloy and manganese metal. The relative standard deviations (RSD, n=11) were in the range of 2.2%-9.4%, and the recoveries were between 95% and 105%. Seven laboratories were selected for the verification test, and the results were basically the same. The contents of lead, arsenic, titanium, copper, nickel, calcium, magnesium and aluminum in four certified reference materials (Caizi-32, YSB C 28618, YSB C 26605) were determined according to the experimental method, and the found results were consistent with the certified values.