BUNSEKI KAGAKU Vol. 63, No. 2, pp. 109-117 2014 2014 The Japan Society for Analytical Chemistry 109 ICP 1 1 1 1 0.1 1 nl ICP ICP ICP He-ICP 3.4 khz Ar-ICP 17.3 khz He-ICP 24 ms Ar-ICP 130 ms He-ICP 3000 K 4000 K Ar-ICP 500 K 1000 K ICP 1 ips Alzheimer Parkinson ips 1 2 ppt ag 10 18 g SPring-8 50 ag 3 nl 4 E-mail : miya@plasma.es.titech.ac.jp 1 : 226-8502 4259-J2-1303 100 S/N ICP zg 10 21 g 100 1000 ICP ICP 5 ICP ICP ICP ICP ICP Pspice Orcad
110 B U N S E K I K A G A K U Vol. 63 2014 Fig. 1 system Schematic diagram of the plasma measurement Fig. 2 Photograph of a time-resolved obserbation on Helium and Argon ICP under single-droplet sample introduction 2 2 1 ICP 3.8 kw 7T84RB ICP 2 2 ICP 4 5 700 pl 2 3 CNT-90, Spectracom Corp. NY, USA 10 mm Fig. 1 R928 50 cm wave-length resolution; 0.027 nm HR4000, Ocean Optics Inc. FL, USA 101.07 mm 50 mm 3 3 1 ICP ICP ICP 60 / EXILIM PRO EX-F1 CASIO 20 L min 1 15 L min 1 540 W 1080 W 30 μm 0.05 MPa 4.0 ms 5 nl ICP Fig. 2 2 3 Fig. 2 ICP 100 ms ICP 20 L min 1 15 L min 1 RF-power 720 W
: ICP 111 Fig. 3 Time-resolved frequeency mesurements on Helium and Argon ICP under the introduction of 5 nl droplets with 0.5 Hz Table 1 Evaluation of the RF resonant frequency by introducing droplets ARCOS Agilent 7700 Ocsilated frequency (MHz) With droplet introduction 27.124 27.172 W/O droplet introduction 27.117 27.110 5 nl 0.5 Hz Fig. 3 Fig. 3 a ICP 3.4 khz 24 ms Fig. 3 b ICP 17.3 khz 130 ms 0.152 W m 1 K 1 0.01772 W m 1 K 1 10 ICP ICP ICP ICP Agilent 7700 SPECTRO ICP ARCOS Spectrometer SPECTRO ICP ARCOS 12 L min 1 1400 W 1.0 L min 1 ICP Table 1 ARCOS 27.124 MHz 27.117 MHz Agilent 7700 27.172 MHz 27.110 MHz 3 2 ICP
112 B U N S E K I K A G A K U Vol. 63 2014 Fig. 4 Time-resolved excitation temperature mesurements on Helium and Argon ICP under the introduction of 5 nl droplets with 0.5 Hz 447.15 nm 501.56 nm 425.12 nm 426.63 nm Fig. 4 a ICP 3000 K 4000 K Fig. 4 b ICP 500 K 1000 K ICP 0.152 W m 1 K 1 0.018 W m 1 K 1 3 3 ICP 20 L min 1 15 L min 1 540 W 1080 W 30 μm 4.0 ms Fig. 5 ICP ICP 5.8 nl 5 nl 3 4 ICP ICP ICP 20 L min 1 15 L min 1 30 μm 0.05 MPa 4.0 ms
: ICP 113 Fig. 5 Relation between the introduced droplet volume on the frequency shift Fig. 6 Relation between the RF-power on the frequency shift during droplet sample introduction Fig. 6 Fig. 6 5 ICP ICP ICP ICP 3 5 Fig. 6 540 W 1080 W 30 μm 0.05 MPa 1.0 ms Fig. 7 Fig. 7
114 B U N S E K I K A G A K U Vol. 63 2014 Fig. 7 Relation between the plasma gas flow rate on the frequency shift during droplet sample introduction Fig. 8 Electrical equivalent circuit of ICP generation by an inductively copled mode Fig. 10 Electrical equivalent circuit used for an electric circuit simulation in which ICP was considerd as being generated with an inductively coupled mode Fig. 9 Electrical equivalent circuit of ICP generation by a capacitive copled mode 4 Pspice Orcad ICP Fig. 8 Lp Rp 6 ICP ICP ICP Fig. 9 Cp 7 ICP Fig. 10 Fig. 11 Fig. 10 Fig. 11 Fig. 10 L H
: ICP 115 Fig. 11 Electrical equivalent circuit used for an electric circuit simulation in which ICP was considerd as being generated with a capacitive coupled mode Fig. 13 Calculated electric circuit simulation results in which ICP was considerd as being generated with a capacitive coupled mode Fig. 12 Calculated electric circuit simulation results in which ICP was considerd as being generated with an inductively coupled mode 2 L = kµ 0 πa n 2 / b k μ 0 H m 1 a m b m n σ Ω α σ = 3. 34 10 6 σ T α σ m 2 T K 8 ICP 3600 K 8.3 10 13 cm 3 ICP 7000 K 2.6 10 13 cm 3 43 Ω 3 Ω ICP Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 12 Fig. 13 ICP
116 B U N S E K I K A G A K U Vol. 63 2014 Table 2 Comparison of He and Ar ICP for droplet sample introduction Herium ICP Argon ICP Robustness for droplet introduction Strong Weak Frequency shift Small ( 3.4 khz) Large ( 17.3 khz) Fluctuation of Exc. Temp. Large ( 7000 K) Small ( 1500 K) Convergence time Fast ( 24 ms) Slow ( 130 ms) Energy copling Capacitive Inductive Inductive Capacitive 5 ICP 1000 ICP ICP ICP RF-power ICP Table 2 5 nl ICP ICP 3.4 khz 24 ms ICP 17.3 khz 130 ms ICP ICP 3000 K 4000 K ICP 500 K 1000 K ICP ICP ICP 1) H. Haraguchi : J. Anal. At. Spectrom., 19, 5 (2004). 2) : 77, 255 (2007). 3) : X 34, 133 (2003). 4) : (Bunseki Kagaku), 59, 363 (2010). 5) : (Bunseki Kagaku), 63, 101 (2014). 6) :, (2000), ( ). 7) : ( ), (2001), ( ). 6) :, (1965), ( ).
: ICP 117 Effects of Droplet Introduction into the ICP Sustained by Free-running RF-generator on Plasma Spectroscopic Characteristics Hidekazu MIYAHARA 1, Yuki KABURAKI 1, Takahiro IWAI 1 and Akitoshi OKINO 1 E-mail : miya@plasma.es.titech.ac.jp 1 Department of Energy Sciences, Tokyo Instutute of Technology, J2-1303, 4259, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8502 (Received August 22, 2013; Accepted October 9, 2013) For stable plasma generation under introducing large-size sample droplets to ICP, we designed and developed free-running ICP. In the system, the impedance shift of the plasma generated by introducing the droplet is immediately cancelled by a shift of the RF resonant frequency of the entire system. To evaluate the shift of the frequency caused by changing the plasma impedance with introducing 5 nl droplets, the frequency shift in the free-running ICP was measured. In the case of Ar-ICP, the frequency increased by 17.3 khz from the base frequency, and then returned to the base frequency in 130 ms. The excitation temperature was about 3000 K decreased and then became about 4000 K increased rapidly. When the same measurement was performed in the case of He-ICP, the resonant frequency decreased by 3.4 khz, and then returned in 24 ms, the excitation temperature was about 500 K increased and then 1000 K decreased. In addition, the frequency fluctuation was increased due to droplet volume in both cases. The cause of the frequency-shift characteristics was also discussed by using an electric circuit simulation. The results showed that the difference of the frequency sifts tendencies between Ar and He ICP can be explained based on the cappling system for RF-power energy transfer. Keywords: ICP; free-running; resonant frequency; temperature sift; plasma stability.