Illustrating Some Principles of Separation Science through Gravitational Field-Flow Fractionation

Abstract

Particle separation is an important but often neglected topic in undergraduate curricula. This article discusses how the method of gravitational field-flow fractionation (GrFFF) can be used to illustrate many principles of separation science and some fundamental concepts of physical chemistry. GrFFF separates particles during their elution through a flat rectangular channel. The mechanism can be readily understood in terms of gravitational settling, laminar fluid flow, and hydrodynamic lift forces. The article outlines material suitable for lecture and laboratory courses in analytical and physical chemistry. A tested laboratory experiment is available.

Pneumatic Flow Injection Analysis-Tandem Spectrometer System for Iron Speciation

“…4,5 There are different techniques available in the literature for the speciation of iron(II) and iron(III), such as potentiometry, 6 micellar electrokinetic chromatography, 7 spectrophotometric measurement, 8 solvent extraction-atomic absorption determination, 9 preconcentration/separation by adsorptionatomic absorption determination, 10 Gran's method, 11 artificial neural network and multivariate calibration, 12 gravitational field-flow fractionation with electrothermal atomic absorption spectrometry, 13 flame atomic absorption spectrometry (FAAS), 14 the H-point standard addition method, 15 and different flow injection analysis (FIA) systems. [16][17][18][19][20][21] However, there are several disadvantages of using these FIA methods. In most these methods, two injections are needed for each sample.…”