Yoshisuke Nakamura

Evaluation of an axially and radially viewed inductively coupled plasma using an échelle spectrometer with wavelength modulation and second-derivative detection

A high-dispersion echelle spectrometer which incorporates wavelength modulation and second-derivative signal detection is used to view analyte emission from an inductively coupled plasma in both the axial (end-on) and radial (side-on) configurations. Movement of the plasma torch assembly between the viewing positions is computer controlled. Performance characteristics such as background intensity, repeatability, background equivalent concentration, limit of detection, dynamic range and interference effects are reported for 24 elements and in general, measurement in the end-on position produces an improvement in sensitivity. Using end-on measurement, the system is applied to the multi-element analysis of a certified reference water.

Determination of rare earth elements in yttrium, lanthanum, gadolinium and ytterbium matrices using an échelle-type spectrometer and inductively coupled plasma atomic emission

A high-resolution echelle spectrometer and inductively coupled plasma atomic emission spectrometry were used for the direct determination of 15 rare earth elements (REEs, except for Pm) in synthetic solutions containing an REE matrix. Yttrium, La, Gd and Yb were used as the REE matrices. Spectral interferences between REEs were investigated and the optimum analytical wavelengths selected with the echelle spectrometer, using wavelength modulation and detection of the second-derivative signals. Background equivalent concentrations and limits of detection were evaluated.

Evaluation of Electrothermal Vaporization, Emission Intensity–Time–Wavelength Measurement and Time Resolution Combined With an Axially Viewed Horizontal Inductively Coupled Plasma Using an Echelle Spectrometer With Wavelength Modulation

ETV using a tungsten boat furnace was studied in combination with an axially viewed (end-on) horizontal ICP for improvement in sensitivity. A high-dispersion echelle spectrometer in which wavelength modulation and second-derivative signal detection are incorporated was used. Time-resolved spectra were obtained by using an emission intensity–time–wavelength profiling method. In order to obtain a high S/B, the heating programme of the ETV system, the flow rate of the transport gas and the delay time are important in addition to the plasma conditions. Once the optimum conditions have been established, reproducible peak appearance times can be obtained. The net emission intensity, repeatability and limit of detection (LOD) obtained by ETV end-on ICP-AES were compared with those obtained by end-on pneumatic nebulization ICP-AES. The improved LODs were close to those obtained by pneumatic nebulization ICP-MS. Discrimination between the Fe impurity in the tungsten boat and spiked Fe was possible using time resolution. Trace amounts of Mn and Al in a large amount of Mo and Fe, respectively, were time-resolved at neighbouring wavelengths. The chemical species of the vaporized materials were identified by X-ray microanalysis. The main disadvantage of the method is that nitric and sulfuric acids cannot be used.

Determination of trace silicon in pure iron oxide by combined distillation-spectrophotometry

1. Van Loon JC (1969) Fresenius Z Anal Chem 246:122 2. Mallett RC, Pearton DCG, Ring EJ, Steele TW (1972) Talanta 19:181 3. Pitts AE, Van Loon JC, Beamish FE (1970) Anal Chim Acta 50:181 4. Strasheim A, Wessels GJ (1963) Appl Spectroscopy 17:65 5. Eckelmans V, Grauwmans E, De Jaegere S (1974) Talanta 21 : 71o5 6. Schnepfe MM, Grimaldi FS (1959) Talanta 16:591 7. Janssen A, Umland F (1970) Fresenius Z Anal Chem 251 : 101 8. Sen Gupta JG (1972) Anal Chim Acta 58:23 9. Lockyer R, Hames GE (1959) Analyst 84:385 10. Abdallah AM, E1-Defrawy MM, Mostafa MA, Sakla AB (1985) Talanta 32:19