Flow injection analysis

Flow injection analysis (FIA) is an approach to chemical analysis that is accomplished by injecting a plug of sample into a flowing carrier stream.[1][2][3] The principle is similar to that of segmented flow analysis (SFA) but no air is injected into the sample or reagent streams.

Contents

Overview

FIA is an automated method in which a sample is injected into a continuous flow of a carrier solution that mixes with other continuously flowing solutions before reaching a detector. Precision is dramatically increased when FIA is used instead of manual injections and as a result very specific FIA systems have been developed for a wide array of analytical techniques.

Principles of Operation

A sample (analyte) is injected into a carrier solution which mixes through radial and convection diffusion with a reagent for a period of time (depends on the flow rate and the coil length and diameter) before the sample passes through a detector to waste. A Peristaltic pump is the most commonly used pump in FIA instruments. FIA can, like SFA, be used for both medical and industrial analyses.

Detectors

A flow through detector is located downstream from the sample injector and records a chemical physical parameter. Various different types of detector can be used[4] For example:

Experiments

An experiment that is used in analytical chemistry lab courses to familiarize students with FIA is the determination of phosphate by flow injection analysis. The experiment involves calibrating an FIA system, optimizing the system for detection of phosphate and finding the amount of phosphate in an unknown sample.

See also

References

  1. ^ Xu, Weihong; Sandford, Richard; Worsfold, Paul; Carlton, Alexandra; Hanrahan, Grady (2005). "Flow Injection Techniques in Aquatic Environmental Analysis: Recent Applications and Technological Advances". Critical Reviews in Analytical Chemistry 35 (3): 237. doi:10.1080/10408340500323362. 
  2. ^ Tyson, Julian F. (1985). "Flow injection analysis techniques for atomic-absorption spectrometry. a review". The Analyst 110 (5): 419. doi:10.1039/an9851000419. PMID 4025835. 
  3. ^ Anastos, N.; Barnett, NW; Hindson, BJ; Lenehan, CE; Lewis, SW (2004). "Comparison of soluble manganese(IV) and acidic potassium permanganate chemiluminescence detection using flow injection and sequential injection analysis for the determination of ascorbic acid in Vitamin C tablets". Talanta 64 (1): 130. doi:10.1016/j.talanta.2004.01.021. PMID 18969577. 
  4. ^ Trojanowicz, M. (2000). Flow injection analysis : instrumentation and applications.. World Scientific. 

Further reading

  • Trojanowicz, Marek (2000). Flow injection analysis: instrumentation and applications. Singapore: World Scientific. ISBN 981-02-2710-8. 
  • Hansen, Elo Harald; Růžička, Jaromír (1988). Flow injection analysis. New York: Wiley. ISBN 0-471-81355-9. 
  • Martínez Calatayud, José (1996). Flow injection analysis of pharmaceuticals: automation in the laboratory. Washington, DC: Taylor & Francis. ISBN 0-7484-0445-7. 
  • Pacey, Gil E.; Karlberg, Bo (1989). Flow injection analysis: a practical guide. Amsterdam: Elsevier. ISBN 0-444-88014-3. 

External links