I. Lopezgarcia et al., PERISTALTIC PUMPS FOURIER-TRANSFORMS - A COUPLING OF INTEREST IN CONTINUOUS-FLOW FLAME ATOMIC-ABSORPTION SPECTROMETRY, Spectrochimica acta, Part B: Atomic spectroscopy, 51(14), 1996, pp. 1761-1768
The use of a simple continuous manifold, together with data treatment
by means of Fourier transforms, permits the dynamic range of flame ato
mic absorption spectrometry to be extended. A peristaltic pump is used
to move the analyte solution, the difference between the pumping flow
rate and the nebulizer uptake rate being compensated by aspirating so
lvent through a T-piece. The time-variable absorbance profile which re
sults from the action of the rollers is transformed into a frequency s
pectrum, the large signal caused by the periodical roller movement bei
ng used as the analytical signal. The effect of different experimental
conditions on the signal is studied and the improvement in the signal
/noise ratio lowers the determination limit. The dynamic range can be
further extended, since the system also permits the measurement of sol
utions which are too concentrated to be measured by direct aspiration.
Calibration is performed by means of a single standard solution.