Interfacing multisyringe flow injection analysis to flame atomic emission spectrometry: an intelligent system for automatic sample dilution and determination of potassium

Abstract

Interfacing automatic flow systems to atomic emission/absorption spectrometry based on flame atomisation techniques may present some difficulties, especially when there are flow interruptions inherent to the technique of automation applied. Therefore, in the present work, different configurations for interfacing multisyringe flow injection analysis (MSFIA) systems to flame-based detectors (flame emission spectrometer in this case) are proposed and compared. To illustrate the feasibility of the selected approach, an intelligent flow system was implemented for in-line dilution of samples prior to determination of potassium content. By selecting the injection volume and the number of dilution channels activated, a dynamic concentration range (1–2000 mg L⁻¹) was established, allowing direct introduction of soil extracts (1–20 mg L⁻¹), parenteral solutions (20–600 mg L⁻¹) and table wines (200–2000 mg L⁻¹). The sampling frequency (three replicates per sample) was about 14 h⁻¹.