Continuous stream analysis

This technique differs from flow injection analysis in the sense that whereas in the latter technique the sample plug is injected into a flowing stream of reagent, in the former technique plugs of reagent are injected into a continuous stream of the sample. Under these conditions the amount of sample in the zone of the reagent will increase as the dispersion increases. The sample will become well... 

Flow injection analysis is a rapid method of automated chemical analysis that allows for quasi-continuous recording of nutrient concentrations in a flowing stream of seawater. The apparatus used for flow injection analysis is generally less expensive and more rugged than that used in segmented continuous flow analysis. A modified flow injection analysis procedure, called reverse flow injection analysis, was adopted by Thompson et al. [213] and has been adapted for the analysis of dissolved silicate in seawater. The reagent is injected into the sample stream in reverse flow injection analysis, rather than vice versa as in flow injection analysis. This results in an increase in sensitivity. 

FTA [5-7] is a version of continuous-flow analysis based on a nonsegmented flowing stream into which highly reproducible volumes of sample are injected, carried through the manifold, and subjected to one or more chemical or biochemical reactions and/or separation processes. Finally, as the stream transports the Anal solution, it passes through a flow cell where a detector is used to monitor a property of the solution that is related to the concentration of the analyte as a... 

Segmentation of the liquid streams by air bubbles is a feature of continuous flow analysis. 

Solvent extraction can be automated in continuous-flow analysis. For both conventional AutoAnalyzer and flow-injection techniques, analytical methods have been devised incorporating a solvent extraction step. In these methods, a peristaltic pump dehvers the hquid streams, and these are mixed in a mixing coil, often filled with glass ballotini the phases are subsequently separated in a simple separator which allows the aqueous and organic phases to stratify. One or both of these phases can then be resampled into the analyser manifold for further reaction and/or measurement. The sample-to-extractant ratio can be varied within the limits normally applying to such operations, but the maximum concentration factor consistent with good operation is normally about 3 1. 

Flow injection analysis (FIA), which was introduced by Ruzicka and Hansen (iz ) and by Stewart et al (iQ), is based on the concept of controlled dispersion of a sample zone when injected into a moving and nonsegmented carrier stream. In continuous flow analysis (CFA), successive samples are mixed and Incubated with reagents on the way toward a flow through detector. The greatest difficulty to overcome in CFA was intermixing of adjacent samples during transport from the injection valve to the detector. In the past, it was widely believed that there are only two ways to prevent carryover in CFA either by the use of turbulent flow or by air... 

Flow injection analysis (FIA) is an automated method which consists in the injection of the sample solution to a continuous stream of an inactive carrier (e.g., a pH buffer or water) [49-51]. The diluted analyte is transported to a reaction spiral where a chromogenic reagent is added to the mixture. The dimensions of the spiral, the volume of the sample injected, and... 

An AWM tracks the progress of laboratory samples through the entire course of an analysis. The laboratory receives a continual stream of samples, each of which is subject to a series of tests and analyses. A second key requirement for workflow management is to control what happens as the workflow s steps are carried out The right programs have to execute in the right order, user input has to be obtained at the right points, and so on. 

Flow cells operating at i = 1 are convenient for the continuous analysis of liquid streams, since the measured current is directly proportional to the concentration of the substance undergoing electrolysis, that is, from (11.6.5), Co(in) = i/nFv. Since this is actually a continuous coulometric analysis, such an analytical method is absolute and does not require calibration or knowledge of mass-transfer parameters, electrode area, etc. (44). 

Flow injection analysis (FIA) is based on the injection of a defined volume of liquid sample into a moving stream of a suitable liquid. It was developed to overcome the disadvantages of batch assay and continuous-flow analysis forms of chemical analysis and as a means of automating wet chemical reactions. In batch assays, the sample is mixed... 

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