FI, SI and Atomic Spectroscopies
Besides UV-VIS, Atomic Absorption and Atomic Emission are the spectroscopies most frequently coupled with FI and/or SI. The main applications are in trace analysis of volatile elements, for environmental and clinical assays. The most often assayed analytes are mercury and arsenic, as well as other elements that can be volatilized by means of suitable chemical reactions (Chalk 2008). Briefly, uses of Flow Injection as a “front end” to Atomic Spectroscopies fall into three categories.

Automation of sample injection into the AA , ICP or Flame Emission instrument
Matrix removal through formation of volatile species, such as hydride generation
Preconcentration of target analytes for improving sensitivity and detection limits

These operations have been combined in ingenious ways, of which hydride
generation and sorbent extraction play a prominent role. Increasingly, novel applications are turning the combination of AS with FI into a powerful research tool. Consider speciation, which allows the evaluation of availability and toxicity of metal complexes, or the monitoring of the extraction rate of a target analyte from soil (Hansen 2006).
The growing area of FI/SI applications can only be sketched in This Tutorial . For more information on SI technique consult Chapter 2, and  for Bead Injection Chapter 3.  

Comprehensive reviews by Hansen and Miró 2008 and by Burguera and Burguera 2008 are highly recommended to anyone interested in this field.

Bibliometrics. S. Chalk, Ch5 in S. D. Kolev, I. McKelvie, Ed. Advances in FIA and Related Techniques. Elsevier, Amsterdam 2008
X.B.Long, M.Miró and E.H.Hansen, Analyst, 131 (2008) 132
Atomic Spectroscopic Detection. E.H.Hansen and M. Miró Ch14 in in S. D. Kolev, I. McKelvie, Ed. Advances in FIA and Related Techniques. Elsevier, Amsterdam 2008.
Atomic Spectroscopy in Flow Analysis. J. L. Burguera and M. Burguera in M. Trojanowitz Advances in Flow Analysis Wiley NY. 2008.