Zeeman atomic absorption spectrometry instrumentation

Zeeman atomic absorption spectrometry Perkin Elmer Gorporation Varian Instruments... 

Nowadays, atomic absorption spectrometry (AAS) systems are comparatively inexpensive element selective detectors, and some of the instruments also show multi(few)-element capability. There are flame (F AAS), cold vapor (CV AAS), hydride-generating (HG AAS), and graphite furnace (GF-AAS) systems. However, the use of AAS-based detectors for on-line speciation analysis is problematic. F AAS is usually not sensitive enough for speciation analysis at "normal" environmental or physiological concentrations and sample intake is high (4—5 ml/min), which complicates on-line hyphenations with LC an auxiliary flow is necessary. CV AAS and HG AAS use selective derivatization for matrix separation and increased sensitivity for the derivatized species. But, the detector response is species dependent and interferences can be a problem. GF AAS requires only a few microliters of sample and provides low detection limits, between 0.1 and 5 gg/1. Matrix interferences are widely eliminated by Zeeman correction and matrix modifiers nevertheless, quantification errors were reported as atomization temperature does not exceed 2900°C. The most critical problem in respect to speciation analysis is the discontinuous measiuement because of the temperature program operation employed, which takes a few minutes. Therefore, GF AAS is unsuitable for on-line hyphenations as chromatograms carmot be monitored with sufficient resolution. 

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