黒鉛炉原子吸光法によるニッケル基耐熱合金中の微量インジウムの定量

抄録

An analytical method has been established for the determination of trace amounts of indium in nickel-base heat-resisting alloys by graphite furnace atomic absorption spectrometry. An alloy was dissolved in hydrofluoric acid and nitric acid. After the solution (20 mm³) was pipetted into a L’vov platform furnace, it was ashed (1173 K-60 s, hydrogen 5 cm³) and atomized (2273 K; ramp 0 s, hold 4 s) by using argon as a purge gas. Atomic absorption of indium was measured at 325.6 nm. The effect of diverse elements was suppressed by peak area measurement. Synthetic calibration solutions were prepared by adding indium standard solution to nickel matrix solutions which had the same acid concentrations as those of the sample solutions. The relative standard deviation of the proposed method was within 2.6% at 18 ppm of indium in nickel-base heat-resisting alloys. The limit by detection (3σ of blank value) was 0.1 ppm of indium, when one gram of the specimen.