Article
A Flow Manifold for Automated On-line Dilution of Standards for Flame Atomic Absorption Spectrometry and its use in a Null Measurement Method
Journal of Analytical Atomic Spectrometry
(1987)
Abstract
A flow manifold that automatically dilutes solutions presented to a flame atomic absorption spectrometer
while maintaining a constant flow to the nebuliser is described. The manifold is based on a fixed-speed pump,
together with a computer-controlled stream switching valve and pump. The computer is also used for data
acquisition and handling. In addition to the production of solutions for a conventional calibration procedure,
the system is also used for a novel calibration procedure whereby the stock standard solution is automatically
diluted by a known factor until its absorbance matches that of the sample. This null measurement method
avoids the need to fit a curve to a set of calibration points. The performance of both methods compares
favourably with the conventional procedure with errors ranging from 0.0 to 4% and no significant bias at the
99% confidence level. Problems with pulsations in the flow caused by peristaltic pump rollers were
encountered with the consequent difficulties of accurate flow-rate measurement. Attempts to improve the
speed of the method by the use of flow injection introduction were not successful owing to these pulsations in
the flow.
Keywords
- Automated calibration,
- flame atomic absorption spectrometry,
- on-line dilution,
- null measurement method
Disciplines
Publication Date
1987
Citation Information
Julian Tyson. "A Flow Manifold for Automated On-line Dilution of Standards for Flame Atomic Absorption Spectrometry and its use in a Null Measurement Method" Journal of Analytical Atomic Spectrometry Vol. 2 (1987) p. 217 Available at: http://works.bepress.com/julian_tyson/10/