Flow injection techniques of method development for flame atomic-absorption spectrometry

Abstract

The flow injection introduction of samples that would be difficult by conventional nebulisation owing to dissolved solid content, viscosity or quenching effects on flame reactions is demonstrated. The various ways of achieving sample dilution by control of volume injected, tube dimensions and flow-rate are discussed and a manifold described for producing solutions for calibration purposes and diluting off-range samples. The important characteristics of the nebuliser and instrument for flow injection work are evaluated. A simple manifold for investigating interference effects is described and its use illustrated for some well known effects. The possibilities of achieving pre-treatment by solvent extraction and extension to include indirect methods are discussed and the role of flow injection procedures in the method development for, and the extension of the range of application of, flame atomic-absorption spectrometry is critically evaluated.

Novel flow injection strategies for study and control of matrix interferences by inductively coupled plasma time-of-flight mass spectrometry

“…for flame atomic-absorption spectrometry. 7 By monitoring the analyte signal as a function of time and knowing the dispersion profile, one can deduce the matrix effect as a function of interferent concentration, and thus evaluate matrix interferences from a single injection.…”

Determination of iron in soils by flow injection atomic absorption spectrometry

“…The effect of changing the injection volume has mainly been investigated for its effect on the dispersion in the manifold (Tyson et al, 1985) but in this work, the selection of the injection volume was not only a function of the dispersion demanded for this particular matrix, but it should also be the smallest possible to avoid the blocking of the burner head. In fact, when the soil extracts were introduced in a conventional way in the atomic absorption spectrophotometer (Soil and Plant Analysis Council, 1992) problems with the blocking of the burner head were observed, probably due to the high level of dissolved solids.…”

A microcomputer-based peak-width method of extended calibration for flow-injection atomic absorption spectrometry

“…With .the incorporation of a flow-injection dilution system, the sample could be diluted on-line for further measurements. Examples of dilution based on flow injection include zone sampling [9], variable volume injection [10], variable dispersion [11] and confluence dilution [12]. The concentration could then be calculated from the normal calibration curve already obtained and fitted by the computer, together with the relevant dispersion information.…”