Experimental comparison of flow-injection analysis and air-segmented continuous flow analysis

A miniature continuous flow analyzer that can be configured for either air-segmented continuous flow analysis (c.f.a.) or flow-injection analysis (f.i.a.) was used to compare the performance of the two techniques in terms of sampling rates, samples and reagent consumption factors and analtical precision. Details of simply dye dispersion experiments and spectrophotometric chloride determinations are presented. Chloride determinations at rates of up to 360 determinations per hour could be achieved with either technique; sample and reagent consumption was less for the air-segmented flow system than for flow-injection systems equipped with either coiled open tubular reactors (0.05 cm i.d.) or single-bead-string reactors. The advantages of single-bead-string reactors for determinations by merging-zones f.i.a. are demonstrated. The c.f.a. and f.i.a. techniques are shown to be complementary, and the relative merits of each for various applications are discussed.