China 
Africa 
Explore chapters and articles related to this topic
Models in Physics and Chemistry
Published in Gabriel A. Wainer, Discrete-Event Modeling and Simulation, 2017
Flow injection analysis (FIA) is used for the automated study of liquid samples. In a flow injection analyzer, a small, fixed volume of a liquid sample is injected into a liquid carrier, which flows through a narrow tube. As a result of convection at the beginning, and later of axial and radial diffusion, this sample is progressively mixed into the carrier as it is transported along the tube. The addition of reagents at different confluence points (which mix with the sample due to radial dispersion) produces reactive or detectable species, which can be sensed by flow-through sensors. Figure 12.14 presents a simple FIA apparatus. This device (called an FIA manifold) consists of a pump (P) that adds carrier solution (nitric acid—HNO3) into a valve that connects to a tube-shaped reactor (L). At the end of the tube, a sensor (B) detects specific properties of the flowing solution. The valve can be turned to allow the flow of the sample (water) into the reactor. The sample is held in a loop (l) and when the valve is rotated, its content flows into the reactor. As a result of the chemical activity between the sample and the carrier solution, a change will be observed in the sensor (B), making it possible to compare the results with those obtained by known samples [13].
Analytical Chemistry
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
bombardment of the surface. This method is considered to be in the same family as X-ray methods because during electron bombardment, the surface can lose energy either by electron emission (the Auger effect, via Auger electron emission) or X-ray emission. These methods are in contrast to X-ray diffraction methods, in which a crystal structure measurement is desired. Flow Injection Analysis (FIA): An analytical protocol that seeks to replace the manual "test tube and beaker" aspects of wet chemical analysis by injecting an analyte in a flowing stream of a carrier reactant. As the analyte flows with the reactant stream, it diffuses into the reactant and product forms. Ultimately, the product zone, under the influence of the moving reactant, is passed into a detector section. The detection devices can consist of the same wide variety as is used in HPLC. The major advantage of flow injection analysis is the automation and decreased uncertainty associated with sampling and reagent addition. Strict control of reagent concentration, flow rate, and analyte volume is possible. Modern applications of FIA include the sequential addition of analyte and reactant in a stream so that the two are "stacked" in an inert carrier. They then mix by the parabolic flow profile of a laminar flowing stream in a tube. This arrangement can be miniaturized within a sampling valve, forming the socalled lab-in-a-valve approach.
Determination of total polyphenols in tea by a flow injection-fiber optic spectrophotometric system
Published in Instrumentation Science & Technology, 2018
Muyessar Qadir, Turghun Muhammad, Mahinur Bakri, Fei Gao
Flow injection analysis (FIA) is a well-established automated analytical technique which is based on injection of a defined volume of sample into a moving carrier solution and propels the sample zone to a certain detector.[19,20] FIA is a simple, convenient, and feasible technique with low sample and reagent consumption, rapid-analysis time, and relative simple instrumentation[21,22]; thus, it is suitable for the determination of large numbers of samples.[23] Fiber optic spectroscopy is a photometric detection technology. Comparing to conventional spectroscopy, it has many advantages such as small size, easy assembly, and few interferences[24] and has been widely used for routine and research tasks.[25,26]