Commercially Available Flow-Injection Analyzers

Much has changed since the first commercial FIA analyzer was introduced by Bifok. This FIA 05 instrument (Ref. 153, Fig. 5.1), developed by the Swedish group of R. Lundin, T. Anfalt, and B. Karlberg in a then typical garage enterprise (actually an abandoned milk store) had a motorized valve, modular flow system but no computer control of the analyzer functions. Later, FIAtron, Lachat and Control Equipment (all U.S.), Hitachi, Jasco, and Soma Kazaku (Japan) as well as Micronal (Brazil) entered the market with different designs. Meanwhile Bifok developed a new generation of FIA instruments and in a joint venture with Tecator (Sweden) marketed these analyzers worldwide. 

Hitachi Ltd. (Instrument Div., Shin Maru Bid. 5-1, Marunouchi Chiyoda-Ku, Tokyo, Japan 100). The company offers a laboratory instrument for serial assays of industrial samples in a single unit. The carrier stream is propelled by a piston pump, samples are aspirated into the injector by means of a peristaltic pump. A sophisticated 16-port valve allows combination of sample and reagent solutions to be introduced by the merging zone technique. General purpose instrument for industrial and environmental analysis. Detector systems have to be acquired separately. 

Furman, Continuous Flow Analysis Theory and Practices (M. K. Schwartz, ed.). Marcel Dekker, New York, 1976. 

Liquid Chromatography Detectors, Journal of Chromatography Library, Vol. 11, Elsevier, Amsterdam, 1977. 

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FIGURE 1.7 Examples of commercially available flow injection analysis instruments (a) FIAlab2500 analyzer from FIAlab Inc., USA, www.flowinjection.com, (b) FIA2000 multichannel analyzer from Burkard, United Kingdom, www.burkardscientific.co.uk, (c) QuikChem 8500 Series Flow Injection Analyzer from Fachat, USA, www.lachatin-struments.com, and (d) flow injection analysis system from MLE company, Dresden, Germany, www.mle-dresden.com. 

Although a large number of chemical macrosensors for electrolyte measurements are commercially available, these sensors do not offer self-testing or self-calibration These functions are realized until now in large volume devices like flow-injection analyzers Just recently, several groups started to develop pTAS, using predominately silicon and glass structures [2-5]... 

The first successful separation of calcium pantothenate in multivitamin preparations that allowed the quantitative determination in <5 min was reported by Jonvel et al. (65). They used a 20-cm Nucleosil 7 Cig reversed-phase column, an acetic acid-water (5 95, v/v) mobile phase at a flow rate of 2 mL/min, and a refractometer as a detector. Samples were simply dissolved in the mobile phase and analyzed without any internal standard. Mean recoveries of the assays of commercially available calcium pantothenate tablets containing also thiamine, riboflavin, niacinamide, and pyridoxine ranged Ifom 96.8% to 104.4%. The detection limit was 50 ng injected. 

More popular for reactions in the millisecond range is the "stopped-flow" technique [4], which consumes less fluid and for which commercial equipment is available (e.g., see Figure 3.7). Over an extremely short time span, liquids are injected into and mixed in a small reaction chamber, and the composition of the mixture is then monitored continuously or analyzed after short, preset reaction times. In contrast to the Hartridge-Roughton reactor, a stopped-flow reactor functions essentially as a micro-batch reactor. 

The UV- and carbohydrate analyzers use a sample injection valve that contains six ports, each pair of which is interconnected. In one orientation of the valve, a sample can be loaded into the sample loop, which becomes a part of the eluent line when the ports are reoriented (by turning the valve handle) (Fig. 5). Valves that allow automated sample introduction at pressures up to 5000 psi without interrupting the eluent flow have been developed and are now available commercially (S2). 

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