Optical emissions, flowing

FF-TLC Forced-flow TLC GD-OES Glow-discharge-optical emission... 

Figure 4.4 Optical emission spectra (OES) measured from (A) dissociation glow and (B) negative glow in DC glow discharge of trimethylsilane (TMS) flow system, 1 seem TMS, 50 mtorr, DC power 5 W.

The continuous operation of LCVD could be controlled, in principle, by the strict controls of the flow rate, the system pressure, and the discharge power. The addition of a residual gas analyzer in each pumping system is advantageous in detecting abnormality in gas flow, occurrence of leakage, etc. The addition of more sophisticated diagnostic devices, such as an optical emission spectrometer, in-line XPS, etc., is often counterproductive because the stability of performance and the maintenance requirement cycle of these devices do not match those for the continuous mode operation of LCVD. The information obtainable by these devices... 

Brennan, M.C. and Svehla, G. (1989) Flow injection determination of boron, copper, molybdenum, tungsten and zinc in organic matrices with direct current plasma optical emission spectrometry, Fresenius Zeitschrift fur Analytische Chemie, 335, pp893-899. 

C. Ortega, M.R. Gomez, R.A. Olsina, M.F. Silva, L.D. Martinez, On-line cloud point preconcentration and determination of gadolinium in urine using flow injection inductively coupled plasma optical emission spectrometry, J. Anal. At. Spectrom. 17 (2002) 530. 

Fig. 48. Atomic oxygen concentration, measured by optical emission actinometry, as a function of radius in a 13.56 MHz oxygen discharge sustained in a diode reactor. The electrode is covered with a reactive film up to a radius of 3.75 cm. This film acts as a sink for atomic oxygen (loading) resulting in significant radial concentration gradients. Such gradients are responsible for etch non-uniformity. Solid lines show the result of mathematical model predictions. After [231]. Pressure 2 torr, gas flow 100 seem.

Emission spectroscopic techniques such as inductively coupled plasma optical emission (ICP-OES) and direct current plasma optical emission (DCP-OES). include the analysis of copper in biological materials (Delves et al.. 1983. Roberts et al., 1985). These techniques, with suitable sample preparation, have sufficient low bias and precision for clinical work but are more expensive and more complex than AAS (Herber et al.. 1982). Flow injection-ICP-OES will be mentioned below. 

McLeod et al. (1984) described the simultaneous determination of Na, K, Ca, Mg, Li. Cu, Fe and Zn in blood serum by flow-injection analysis - inductively coupled plasma optical emission spectrometry (FIA-ICP-OES) using aqueous synthetic multi-element solutions for calibration. With an injected volume of 20 fiL the performane data for copper in an 1 + 1 diluted serum ranged for precision from 1.1% to 2.2% with a detection limit of 0.01 mg/L. 

Metal ions were detected using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES, Optima 8000 Perkin Elmer). The argon and air flow rate was adjusted to 12 lit/min and 1.2 lit/min, respectively. Two ICP standard solutions were used to do the calibration curves. 

Although originally FIA was conceived as a special technique for delivery of a sample segment into the instrument, the combination of flow injection as a sample pretreatment tool with atomic spectrometry has been shown to be of great potential for enhancing the selectivity and sensitivity of the measurements. Moreover, contamination problems are reduced due to the closed system used, making this interface suitable for ultratrace determination of metal species. Hyphenated techniques such as FIA/ SIA with flame atomic absorption spectrometry, inductively coupled plasma (ICP)-optical emission spectrometry, and ICP-mass spectrometry (MS) have been exploited extensively in recent years. The major attraction of FIA-ICP-MS is its exceptional multi-elemental sensitivity combined with high speed of analysis. In addition, the possibility of... 

A comparison of flow injection sample introduction in the determination of Se (As, Sb) by hydride generation AAS and ICP optical emission spectroscopy has been carried out [102], while the isotopic determination of Se in biological materials using ICP-MS has been reported [103]. 

---