Abstract. For the characterisation of trace elements in high purityMo and W analytical methods with a detection limit in the ng/grange have to be used. Today mass spectrometric methods are state of the art for such applications. However, these methods in case of refractory metal analysis are time consuming, expensive, limited by isobaric interferences and therefore not very suitable for quality control in an industrial laboratory. With respect to these drawbacks a cost and time efficient method was developed by on-line coupling of an ion chromatographic system to a simultaneous ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry) instrument. Within the limitations caused by the hard-and software of the system all parameters such as eluent concentration and flow rate, nebulizer and plasma gas flow, sampling frequency, integration time and the number of simultaneously measured emission lines were optimised. Further enhancement of the sensitivity was achieved by the use of an ultrasonic nebulizer pushing the detection limits down to the pg/g-and ng/g-range for 22 representative elements.Key words: ultra trace analysis, molybdenum, tungsten, on-line coupling, ion chromatography, ICP-AES.During the last decade, certified quality assurance and laboratory accreditation systems, namely ISO 9000 and EN 45000, have been established in many fields of trade and industry. The standards of these systems require a precise characterisation of quality relevant product properties. Several years ago, guaranteed maximum values of trace impurities were regarded as sufficient quality criteria with respect to the chemical composition of the product. Meanwhile these values have been replaced by measures of the process capability. Since the calculation of the critical process capabil-* Dedicated to Professor Dr. rer. nat. Dr. h. c. Hubertus Nickel on the occasion of his 65th birthday ** To whom correspondence should be addressed ity is based on the difference between the mean value for all production lots and the specified maximum level divided by three times the standard deviation, it is no longer acceptable that the determination limit of the analytical method is equal to the guaranteed maximum concentration level. Additionally the purity of refractory metals was increased [1][2][3] and therefore the number of elements which can be determined directly by atomic spectrometric methods such as AAS (Atomic Absorption Spectrometry), GAAS (Graphite Furnace AAS) and ICP-AES were reduced dramatically.As a consequence, mass spectrometric procedures like SIMS (Secondary Ion Mass Spectrometry), GDMS (Glow Discharge Mass Spectrometry) and ICP-MS (ICP-Mass Spectrometry) have been used [4]. SIMS and GDMS are time consuming and very expensive, and although serious efforts were made to improve the analytical quality, both methods due to their low sample consumption do not provide reliable results especially for bulk analysis in refractory metals. Since samples are dissolved and thereby homogenised prior to analysis with ICP-MS, those resu...
The quantitative analysis of thin films containing light elements is very important in improving the coating processes and technological properties of the products. In order to review the state of the art of modern analytical techniques for such applications, the model systems SiOXNY and AlOXNY were selected. Over 1000 abstracts were screened, and the relevant literature was evaluated to give a comprehensive overview of instruments, analytical procedures and results, film types, deposition methods, and investigation goals. From more than 150 citations, the limitations, drawbacks, and pitfalls of the different methods were extracted and reviewed critically, while in addition, improvements were proposed where possible. These suggestions are combined with the newest results of investigation by the authors of this paper. Recommendations concerning the optimized combination of analytical methods for different analytical problems have been worked out on the basis of all results. Analysis of various multicomponent systems containing light elements demonstrated the applicability of the different methods of analysis in combination to all film systems with related compositions.
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