Flow-injection analysis refractive index effect

Flow-injection analysis (FIA) is a technique for automating chemical analyses. The principles of FIA are reviewed here. Methods for applying FIA to the anayses of nitrate, nitrite, phosphate, silicate, and total amino acids in seawater are examined. Analyses of other nutrients, metals, and carbonate system components are also discussed. Various techniques to eliminate the refractive index effect are reviewed. Finally, several examples of the application of FIA to oceanographic problems are presented. 

FIGURE 4.13 Schlieren signals recorded for different solutions with the same refractive index. Carrier stream = water coiled reactor length = 100 cm a. b, c, d = 2.0 mol L-1 HC1,11.2% (m/v) sucrose, 14% (m/v) glycerol, and 24.13% (m/v) ethanol respectively. Other conditions are as in Fig. 4.13. Reprinted from Anal. Chim. Acta 234 (1990) 153, E.A.G. Zagatto, M.A.Z. Arruda, A.O. Jacintho, I.L. Mattos, Compensation of the Schlieren effect in flow-injection analysis by using dual-wavelength spectrophotometry, with permission from Elsevier (Ref [28]). 

H.-H. Liu, P.K. Dasgupta, Dual-wavelength photometry with light emitting diodes. Compensation of refractive index and turbidity effects in flow-injection analysis, Anal. Chim. Acta 289 (1994) 347. 

G. Ham, Refractive Index Effect in Flow Injection Analysis. Anal. Proc., 18 (1981) 69. 

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