Chromatographic separations coupled with atomic spectrometr

Investigations of lead speciation in various environmental samples have relied upon gas and liquid chromatographic separations coupled to mass spectrometric and atomic absorption spectrometric detectors. The combination of atomic absorption spectrometry with gas chromatography (GC-AAS) has proved to be the most widely applied technique. Sample types have included air, surface water, air particulates, sediments, grass, and clinical materials such as blood. A review of speciation analyses of organolead compounds by GC-AAS, with emphasis on environmental materials, was published (Lobinski et al., 1994). 

A strong preference in speciation analysis is to use a separation step that can be combined with a detection step in an on-line system [45]. In such coupling, analytical selectivity relies on the application of different chromatographic or electrophoretic methods, while the use of atomic spectrometric techniques assures high sensitivity and f>t-for-purpose limits of detection (LoDs). However, hyphenated techniques with element-specif>c detection do not provide structural information on the species. If appropriate standards are available, the assignation of chromatographic peaks can be accomplished by spiking experiments. On the... 

The association of a spectrometer with the liquid chromatograph is usually for the purpose of structure elucidation of the eluted solute, a procedure that will be discussed in a later chapter. The association of tui atomic spectrometer with the liquid chromatograph, in contrast, is almost exclusively for the specific detection of the metalic and semi-metalic elements. The atomic spectrometer is a highly specific detector, and for element detection perhaps more so than the electrochemical detector. However, in general, a flame atomic absorption spectrometric (AAS) system is not as sensitive. If an atomic emission spectrometer or an atomic fluorescence spectrometer is employed then multi-element detection is possible. The inductively coupled plasma spectrometer can also, under some circumstances, provide multi-element detection but all three instruments are extremely expensive particularly in terms of an LC detector. It follows that most LC/AAS combinations employ a flame atomic absorption spectrometer or occasionally an atomic spectrometer fitted with a graphite furnace. Furthermore the spectrometer is usually set to monitor one element only, throughout the development of any given separation. 

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