本文介绍一种氧一氩混合气氛、直流电弧两阶段电流激发试样的光谱测定法。它可降低背景,使铱有效地分馏出来,从而提高铱的光谱分析灵敏度,并可定量测定高纯铑中十四个杂质元素,灵敏度为:铂、铱5×10~(-5)％;钯、铝、铁、镍、钴、锡、银、铜、镁、锰1×10~(-4)～2×10~(-4)％;铅、金2×10~(-4)～4×10~(-4)％。相对误差不超过30％。 This article describes a mixed oxygen-argon atmosphere, DC arc two-phase current excitation sample spectrometry. It can reduce the background and make the iridium fractionally distributed effectively, so as to improve the sensitivity of iridium spectral analysis and quantify fourteen impurity elements in high purity rhodium. The sensitivities are 5 × 10 ~ (-5)% of platinum and iridium, 1 × 10 -4 to 2 × 10 -4% of palladium, aluminum, iron, nickel, cobalt, tin, silver, copper, magnesium and manganese; lead and gold 2 × 10 -4 ~ 4 × 10 ~ (-4)%. The relative error does not exceed 30%.