Instrumentelle Methoden der anorganischen Elementanalytik

Abstract

Instrumental element analysis has developed enormously during the past decades. It has rightfully assumed a major role in the analytical laboratory in the field of materials science, environmental analysis, monitoring and research. Due to its high accuracy, classical chemical analysis is still most useful for elemental determinations at major levels and for special applications. In a modem inorganic analytical laboratory, a variety of different instmmental techniques is employed for qualitative and quantitative analysis, covering practically all the elements of the periodic system in a variety of different matrices, from major to trace and ultratrace mass levels. The prerequisite for atomic spectroscopy is the step of excitation, normally in combination with a process of atomization. From a number of different atomization processes currently used, inductively coupled plasma (ICP) is now the most prominent. The atomic spectrometric methods commonly employed in an analytical laboratory are described. These include atomic absorption, both with flame and graphite furnace, ICP atomic emission and ICP mass spectrometry, X-ray fluorescence together with ion chromatography as a non-spectrometric analytical process. The different instrumental techniques are critically compared in relation to number of detectable elements and species, limits of detection, precision, sample throughput, dynamic concentration range, degree of automation, and cost of equipment. Moreover, the importance of sampling and sample treatment prior to the analytical determination, quality assurance, and mode of automation are related both to the present situation and future trends in instrumental element analysis.