1,025 research outputs found
The role of atomic fluorescence spectrometry in the automatic environmental monitoring of trace element analysis
Considerable attention has been drawn to the environmental levels of mercury, arsenic, selenium and antimony in the last decade. Legislative and environmental pressure has forced levels to be lowered and this has created an additional burden for analytical chemists. Not only does an analysis have to reach lower detection levels, but it also has to be seen to be correct. Atomic fluorescence detection, especially when coupled to vapour generation techniques, offers both sensitivity and specificity
Design and operation of an autosampler controlled flow-injection preconcentration system for lead determination by flame atomic absorption spectrometry
Flow-injection manifolds are described which allow the preconcentration
of lead for flame atomic absorption determinations, using
columns contained within the sample loop of an injection valve. An
interface was designed which allowed the valves and pump in the
system to be controlled by an autosampler which enabled precise
timing of preconcentration and elution steps. The effects of sample
flow rate, buffer pH and buffer type for preconcentration and
eluent concentration and flow rate were investigated in order to
obtain optimum performance of the system. A 50-times improvement
in detection limits over conventional sample introduction was
obtained for a sample volume of approximately 12 ml, preconcentrated for
150 s. The injection of eluent, as opposed to the use of a
continuously flowing eluent stream, enabled this reagent to be
conserved
An accurate fast screening for total and inorganic arsenic in rice grain using hydride generation atomic fluorescence spectrometry (HG-AFS)
Two novel methods based on hydride generation atomic fluorescence spectrometry for the accurate screening of total and inorganic arsenic (As) in rice grain digests in 5 and 2 minutes, respectively, are proposed here.</p
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