ガスクロマトグラフィー/ヘリウムマイクロ波誘導プラズマ発光分析法によるベリリウム及びクロムのアセチルアセトン錯体の定量

抄録

Atmospheric pressure helium microwave induced plasma sustained with a Beenakker type cavity (He-MIP), which is very useful for the determination of metallic and non-metallic elements, has not yet been applied to volatile β-diketonates. The purpose of this work is to investigate optimum conditions for the determination of Be and Cr acetylacetonates with GC/ He-MIP emission spectrometry. A OV-1 coated fused silica capillary column (0.53 mm i. d., 10 m long, 2μm film thickness) and a TM₀₁₀, Beenakker type cavity were used. The most critical parameters were plasma power and plasma gas flow rate. Optimum conditions for Be II 313.01nm (these two lines could not be resolved with a monochromator used) with 1 mm i.d. discharge tube were as follows: microwave power, 60 W (10 W reflected); carrier gas flow rate, 15 ml/min; plasma gas flow rate, 600 ml/min. In general, gas flow rate influenced emission intensities of ionic lines more severely than those of atomic lines. Each special distribution of emission intensity of Be II 313.0 nm, Be I 234.9 nm and He I 388.9 nm was different. The linear dynamic range was almost 10⁴, and the limits of detection (S/N=3) were 0.1 pg for Be and 9 pg for Cr, respectively. The relative standard deviation was 11 % at 1.7 pg of Be.