Atomic emission spectroscopy multielement detection

Atomic emission spectroscopy apparatus, 77,78-79t,80 procedure, 77,78-79t,80 multielement detection, 75 SIT, 31-56... 

Atomic emission spectroscopy with inductive coupled exitation (ICP-AES), although quite costly, is important for multielement determination with high sample rate. Neutron activation analysis (NAA) is a powerful detection method but costly in terms of both financial and work expenditures. X-ray fluorescence (XRF) methods are perfect multielement methods with high sampling rate. ICP-MS is also applied. 

Atomic absorption remains a staple of forensic chemistry, given its low cost, simple operation, and easy maintenance. The limitations are related to versatility. Unless multielement lamps are used, only one element can be tested for at a time, and each element requires a separate lamp and instrument optimization. For small target lists such as a list of barium, antimony, and lead for GSR, this is not onerous, but still is inconvenient. Limits of detection are in the low-ppm to high-ppb range for most elements, As a result, a few forensic laboratories have turned to inductively coupled plasma atomic emission spectroscopy (ICP-AES) for additional elemental analysis capability. 

Multielement analysis will become more important in industrial hygiene analysis as the number of elements per sample and the numbers of samples increases. Additional requirements that will push development of atomic absorption techniques and may encourage the use of new techniques are lower detction and sample speciation. Sample speciation will probably require the use of a chromatographic technique coupled to the spectroscopic instrumentation as an elemental detector. This type of instrumental marriage will not be seen in routine analysis. The use of Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) (17), Zeeman-effect atomic absorption spectroscopy (ZAA) (18), and X-ray fluorescence (XRF) (19) will increase in industrial hygiene laboratories because they each offer advantages or detection that AAS does not. 

Oua/itative and Semiquantitative Applications Because ICPMS is easily adapted to multielement analyses, it is well suited to the rapid characterization and semiquantitative analysis of various types of naturally occurring and manufactured complex materials. Generally, detection limits arc better than those for optical emission ICP and compete with detection limits for electrothermal atomic absorption spectroscopy. 

Four modes of atomic spectroscopy have been interfaced for chromatographic detection, fiame emission (FES), atomic absorption (AAS), atomic fluorescence (AFS), and atomic plasma emission (APES) [2-3]. In contrast to AAS, APES can accomplish simultaneous multielement determination, while giving a good dynamic measurement range and high sensitivities and selectivities over background elements in many cases. 

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