Gallium metal analysis

Table III. Analysis of Gallium Metal Impurities in ppm Weight...

Atomic absorption spectroscopy of VPD solutions (VPD-AAS) and instrumental neutron activation analysis (INAA) offer similar detection limits for metallic impurities with silicon substrates. The main advantage of TXRF, compared to VPD-AAS, is its multielement capability AAS is a sequential technique that requires a specific lamp to detect each element. Furthermore, the problem of blank values is of little importance with TXRF because no handling of the analytical solution is involved. On the other hand, adequately sensitive detection of sodium is possible only by using VPD-AAS. INAA is basically a bulk analysis technique, while TXRF is sensitive only to the surface. In addition, TXRF is fast, with an typical analysis time of 1000 s turn-around times for INAA are on the order of weeks. Gallium arsenide surfaces can be analyzed neither by AAS nor by INAA. 

Fluorimetry is generally used if there is no colorimetric method sufficiently sensitive or selective for the substance to be determined. In inorganic analysis the most frequent applications are for the determination of metal ions as fluorescent organic complexes. Many of the complexes of oxine fluoresce strongly aluminium, zinc, magnesium, and gallium are sometimes determined at low concentrations by this method. Aluminium forms fluorescent complexes with the dyestuff eriochrome blue black RC (pontachrome blue black R), whilst beryllium forms a fluorescent complex with quinizarin. 

The conventional method for quantitative analysis of gallium in aqueous media is atomic absorption spectroscopy (qv). High purity metallic gallium is characterized by trace impurity analysis using spark source (15) or glow discharge mass spectrometry (qv) (16). 

Mercury and Gallium a General Electric TRIGA reactor provides slow neutrons for the neutron activation analysis of these metals at the 10-50-ppb detection level. 

Kleppa, O. J. Thermodynamic Analysis of Binary Liquid Alloys of Group IIB Metals-I. The Systems Zink—Cadmium, Zink—Gallium, Zink—Indium and Zink—Tin. Acta Met. 6, 225 (1958). 

The Chitopearr resin was packed in a glass column (inner diameter 1. 4 cm, bed height 4.3 cm). The column was first equilibrated with a 20 mM MES buffer containing 20 mM NaCI and 10 mM 2-mercaptoethanol. Then 60 ml of the MES buffer containing metal ion was applied at the flow rate of O.S ml/min. Adsorption capabilities of the ligands were examined for cadmium, gallium, cupric, zinc, or nickel ion. After the column was washed with MES buffer, the adsorbed metal ion was eluted with the MES buffer (pH of which was adjusted to pH 2.0). In order to examine effects of pH on the adsorption, pH of the MES buffer was varied from pH S to pH 9. The eluted solution was collected as several fractions of 10 ml each, and the metal concentration of each fraction was determined with atomic adsorption analysis (SAS 7S00A, Seiko Instruments, Japan). Total amount of the eluted metal ion was defined as the adsorbed metal ion on the resin. The total amount of the adsorbed metal ion was divided by the total amount of immobilized protein to calculate the number of metal molecules bound to one mole of the protein. The adsorption experiments were carried out multiple times, and the maximum experimental error was 25%. 

Chemical shifts and coupling constants have been determined in for example cyclopropyl magnesium bromide and the compounds formed with gallium, silicon, mercury, tin and lead. A complete analysis of the metal satellite spectra of tetracyclop-ropyl lead and tin and dicyclopropyl mercury has been presented ... 

In the analysis of high purity metals, trace elements were pre-concentrated by partial dissolution of the matrix. The remaining small part of the matrix retains all trace elements that are electrochemically less noble than the matrix [79,80]. In this way the trace elements were pre-concentrated from silver-, cadmium-, gallium-, indium-, zinc-, lead-, manganese-, aluminium-, and lead-antimony alloys. 

---