Automatic determination of optimum dilution levels for laser-enhanced ionization detection of matrix-interfered sample by flow injection
Journal
The Analyst
Journal Volume
120
Journal Issue
10
Pages
2593-2599
Date Issued
1995
Author(s)
Wang, S.-C.
KING-CHUEN LIN
Abstract
A flow injection (FI) system is interfaced to laser-enhanced ionization (LEI) apparatus to handle the sample introduction. With the use of FI-LEI apparatus, the electrical interference induced by the matrix may be effectively diminished. A significant LEI signal of trace In is recovered in a solution containing an Na-matrix concentration greater than the threshold level, 4-10 ppm (μg ml-1) in our conditions, at which no conventional LEI signal is detectable. The dilution gradient, resulting from injection of a water plug into the carrier stream of sample solution, leads to the appearance of a double-peak LEI signal. By taking into account the dispersion behaviour of sample solution and the ion-sheath effect, we are able to derive an explicit formula. According to the formula, we may successfully predict the measured intensity of the FI-LEI signal and characterize the features of the double-peak observed.
SDGs
Type
journal article