氢化物发生-原子荧光光谱法同时测定镍基高温合金中铋和碲

Simultaneous determination of bismuth and tellurium in nickel-base superalloy by hydride generation-atomic fluorescence spectrometry

采用盐酸、硝酸混合酸溶解样品,在盐酸介质中加热预还原,以柠檬酸和氟化铵作干扰抑制剂,盐酸（1＋9）为载流,控制硼氢化钾的质量浓度为20 g/L,建立了氢化物发生-原子荧光光谱法同时测定高温镍基合金中痕量铋和碲的方法.实验表明：铋和碲的质量浓度均在2～10 μg/L以内与相应的荧光强度呈线性关系,方法的检出限分别为0.000 3μg/L和0.002μg/L.干扰试验表明：铋、碲在10 μg/L以内对彼此无干扰;加入5.0 mL 400 g/L柠檬酸溶液、5.0 mL 200 g/L氟化铵溶液可消除钴、铌、钼、铜对铋、碲测定的干扰;基体镍和主量元素铬、铁对铋、碲测定的干扰可通过基体匹配法消除.采用方法对高温镍基合金标准样品进行测定,测定值与认定值相符,结果的相对标准偏差（RSD,n=6）均不大于5％.

The sample was dissolved with mixed acid of hydrochloric acid and nitric acid.After heating for pre-reduction in hydrochloric acid medium and controlling the mass concentration of potassium borohydride as 20 g/L,the content of bismuth and tellurium in nickel-based superalloy was simultaneously determined by hydride generation atomic fluorescence spectrometry with citric acid and ammonium fluoride as interference inhibitor and hydrochloric acid （1＋9） as flow carrier.The results indicated that the fluorescence intensity of both bismuth and tellurium showed good linearity with their mass concentration in range of 2-10 μg/L.The detection limit of method for bismuth and tellurium was 0.000 3 μg/L and 0.002 μg/L,respectively.The interference test showed that bismuth and tellurium had no mutual interference when the mass concentration was less than 10 μg/L.The interference of cobalt,niobium,molybdenum and copper with bismuth and tellurium could be eliminated by adding 5.0 mL of 400 g/L citric acid solution and 5.0 mL of 200 g/L ammonium fluoride solution.The interference of matrix nickel and major components （chromium and iron） could be eliminated by matrix matching method.The proposed method was applied to the determination of nickel-based superalloy certified reference materials.The results were consistent with the certified values.The relative standard deviations （RSD,n=6） were not more than 5%.