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Novel detection techniques for flow analysis procedures
Abstract
Flow analysis procedures have used a wide variety of detectors. Magnetic susceptibility and graphite furnace atomic absorption spectrometry are two detection techniques with limited applicability to flow procedures. Most magnetic susceptibility balances are not applicable to flowing streams. The use of GFAAS has been limited due to the presence of several timing problems. The Johnson Matthey magnetic susceptibility balance is readily adaptable to flowing streams. Analytical parameters such as detection limits and sensitivity were determined for several ferromagnetic and paramagnetic species. Retention of the metal cations on a column of ion exchange resin situated within the poles of the magnets allowed preconcentration of the cations. The passage of a stream of borohydride through the column containing the immobilized cations caused a dramatic increase in signal. A simple method for calibrating the temperatures of the drying stage of the GFAAS program based on the visual observation of the melting of a number of compounds is presented. Recirculating loop technology was used to devise an interface between a flow injection manifold and a GFAAS system. The use of a recirculating loop eliminates the timing problems common to FIA-GFAAS. A number of Pb solutions of known concentration were analyzed and accurate results obtained. Preconcentration of Pb on C-18 columns and various ion exchange resins was performed before introduction into the recirculating loop. Once the system had been shown to yield accurate results, wine samples were analyzed. The determination of Pb in wines is difficult due to the low concentration of Pb in wines and the complex matrix. Flow analysis procedures were used to isolate the Pb from the matrix before analysis by GFAAS.
Subject Area
Analytical chemistry
Recommended Citation
LaRue, Rodney Mark, "Novel detection techniques for flow analysis procedures" (1993). Doctoral Dissertations Available from Proquest. AAI9408299.
https://scholarworks.umass.edu/dissertations/AAI9408299