1998 Volume 14 Issue 3 Pages 553-558
A novel FIA system for CO2 was constructed and compared with a N,N,N′,N′-tetrakis-2-hydroxylethyl ethylenediamine(THEED)-coated quartz crystal microbalance (QCM) for the determination of CO2 in wine and beer samples. This FIA method is based on the use of a gas-permeable membrane to separate CO2 from a carrier stream of 0.5 mol/l phosphate buffer (pH 6.0) into a recipient stream of 10 mmol/l tris(hydroxymethylamino)methane (Tris) containing 1.0 mmol/l KCl and a piezoelectric impedance sensor to follow the conductance change occurring in the acceptor solution. Although the results for real samples obtained by the FIA, the QCM and the conventional titrimetric methods, respectively, agree well with each other, the FIA method offers the best precision. The FIA method is also characterized by its high throughput, promising sensitivity, excellent selectivity, low cost and easy manipulation, etc. The influence of some experimental parameters on the FIA’s performance is discussed in detail.