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Mixed copper and titanium hydride powder was hot-pressed and characterized by Carrier Gas Hot Extraction, XRay Diffraction, Thermal Gravimetric Analysis coupled with Mass Spectrometry, and Scanning Electron Microscopy.
The hot-pressed and five conventional samples were applied for calibration of hydrogen in Glow Discharge Optical Emission and Mass Spectrometry. Up to the introduction of 15 ng/s hydrogen the Emission yield model is useful in Glow Discharge Optical Emission Spectrometry. A correlation between saturation and even reversal of the emission yield of the spectral lines H121, H486 and H656 and low sputtering rates was found. Hydrogen effects exist for the spectral lines of Cu(II) 219 and Ti(I) 399. In Glow Discharge Mass Spectrometry, a linear dependency of the 1H ion current on the sputtered mass per time exists over the total range of hydrogen content investigated. Hydrogen effects also exist for the sensitivity of 48Ti and 63Cu. The sputtering rate of two-phase materials depends linearly on the sputtered mass per time of one phase, which allows the sputtering rate of two-phase materials with known composition to be predicted.
The performance of glow discharge mass spectrometry (GD-MS) is investigated for the accurate quantification of metallic impurities and oxygen in solid samples using the fast flow source GD-MS instrument ELEMENT GD.
Different quantification approaches based on relative and absolute sensitivity factors are evaluated for the determination of metallic impurities using three sample matrixes (Al, Cu and Zn). The effect of the discharge conditions (voltage, current, discharge gas pressure/flow) on the sensitivity is investigated and the parameters are optimized to favour matrix independent calibrations. Improved standard relative sensitivity factors (StdRSFs) are calculated under optimal conditions based on multi-matrix calibrations. The sputtering rate corrected calibration is also presented as a multi-matrix calibration approach.
The capabilities of GD-MS for oxygen determination are also investigated using a set of new conductive samples containing oxygen with mass fractions in the percent range in three different matrices (Al, Mg and Cu) produced by a sintering process. Poor limits of detection (in the order of g/kg) were obtained as consequence of the reduced sensitivity of oxygen in GD-MS and high oxygen background signal intensity as well as its variations. The absolute sensitivity procedure is shown as a matrix-independent approach, which provides quantitative values consistent with those obtained by carrier gas hot extraction (CGHE).
Direct current (DC) fast flow glow discharge mass spectrometry is an important and versatile tool for multielemental trace analysis of conductive solid materials down to the µg/kg level. Special benefits are minimum demands on sample preparation, avoiding losses and contamination, and only short analysis time.
For fast flow GD sources, the quantification strategy based on relative standard sensitivity factors (Standard RSFs) which are independent of matrix is not sufficiently satisfying regarding accuracy for each matrix and element [1]. Therefore matrix-matched calibration samples (MMCS) are required to achieve reliable quantification. In fact, the list of existing certified reference materials (CRM) appropri-ate for calibration in trace analysis is rather short.
Convenient synthesis of homogeneous MMCS, as e.g. easily obtained in liquid sampling spectrometry, can facilitate the application of fast flow GD-MS for quantification of impurities in a variety of matrices.
Pressing of metal powders for the preparation of MMCS for GD-MS was suggested earlier [2], the method was further modified by use of analyte solutions for doping of rather pure metal powders such as Cu and Zn [3], but has not yet been applied Ni matrix.
In the present work we describe the determination of matrix-dependent relative sensitivity factors (RSFs) for Mg, Al, Cr, Mn, Fe, Co, Cu, Zn, Ag, Cd, Tl, Pb and Bi in pure Ni by using the liquid doping approach for the preparation of synthetic pressed Ni-powder samples. A four point-calibration was used applying the fast flow glow discharge mass spectrometer, Element GD (Thermo Fisher). The determined RSF were verified against suitable CRM and compared with the standard RSF given by the supplier of the instrument.
The obtained results demonstrate a satisfying Agreement with the certified values of the CRM and a significant improvement for the quantification of most of the determined elements in comparison with standard RSF.