Flow Injection Analysis Techniques in Atomic Spectroscopy

Abstract

Flow injection analysis (FIA), developed for the automation of serial assays, has become a powerful tool most adequate for on‐line performing any sample preparation before final measurement (e.g. sample dissolution, dilutions, matrix removal, and analyte preconcentration). It is not surprising that the combination of FIA with atomic spectrometric techniques has enlarged the analytical potential of atomic methods and expanded their field of applications, allowing also for greener procedures. The variety of sample manipulation processes that can be covered today by FIA is amazing, and therefore, the general instrumentation required is reviewed in this contribution. The description of the different flow strategies is carried out according to a hierarchy going from simple dilutions, reagent mixing, or standard additions, to more sophisticated flow manifolds such as those based on the use of two phases (e.g. gas–liquid, liquid–liquid, or solid–liquid) for separation/preconcentration purposes. Modern approaches allowing for on‐line decomposition/dissolution of solid samples (e.g. photo‐oxidation and microwave heating) are also described. The coupling of the above‐mentioned flow methodologies to a variety of atomization/excitation/ionization sources (flames, quartz tubes, graphite furnaces, inductively coupled plasmas, microwave induced plasmas, glow discharges, etc.) is detailed, aiming to show the usefulness of this combination for atomic techniques based on either photon measurements (absorption, emission, and fluorescence) or ion measurements (mass spectrometry, MS).