Integrated flow injection analysis

Liu J., Olsson G., and Mattiasson B., Short-term BOD (BODst) as a parameter for online monitoring of biological treatment process Part 11 Instrumentation of integrated flow injection analysis (ElA) system for BODst estimation. Biosens. Bioelectron., 20, 571-578, 2004. 

Sample preparation, injection, calibration, and data collection, must be automated for process analysis. Methods used for flow injection analysis (FLA) are also useful for reliable sampling for process LC systems.1 Dynamic dilution is a technique that is used extensively in FIA.13 In this technique, sample from a loop or slot of a valve is diluted as it is transferred to a HPLC injection valve for analysis. As the diluted sample plug passes through the HPLC valve it is switched and the sample is injected onto the HPLC column for separation. The sample transfer time typically is determined with a refractive index detector and valve switching, which can be controlled by an integrator or computer. The transfer time is very reproducible. Calibration is typically done by external standardization using normalization by response factor. Internal standardization has also been used. To detect upsets or for process optimization, absolute numbers are not always needed. An alternative to... 

As shown, the system incorporates an integrated plate changer that accommodates plates for analysis as well as plates for collecting fractions of interest. Plates can be of different formats for sampling and collection, for example, a 384-well plate could be used for samples and a 96-well plate for collection (of course, the same plate type may be used for both sampling and collection). The system also incorporates a dedicated rinse station at the fraction collection end. The number of fractions and the time intervals for collection are defined by the user and automatically controlled by the software. In this way, analytes can be isolated and collected using /.tPLC. Collected fractions can, for example, be injected onto MS instrumentation with minimal cycle time by employing a flow injection analysis approach. 

The structural integrity of M2D-C3-0-(E0)ra-CH3 was maintained for all solid media investigated, as confirmed by qualitative analysis of the flow injection analysis (FIA) API-MS spectra (example shown in Fig. 2.8.10a). Intercalation of the surfactant solution between the clay layers was considered as the likely cause of the reduced recovery on montmorillonite (74%), according to experimental observations and... 

The (Bio-pF-EIS-CAP) sensors were integrated in flow injection analysis systems. The medium components were monitored online. 

The focusing bi-laminating micro mixer was realized in the framework of the development of a flow injection analysis (FIA) system [114,115]. The mixer is placed downstream of the two-fold injection of sample and reagent streams into the carrier. Thereafter, the mixed stream enters a reaction chamber and finally passes a detector. An easy integration is required, as the mixing element is part of an integrated system which has the minimization of size as one issue. 

Spectrophotometric techniques combined with flow injection analysis (FIA) and on-line preconcentration can meet the required detection limits for natural Fe concentrations in aquatic systems (Table 7.2) by also using very specific and sensitive ligands, such as ferrozine [3-(2-bipyridyl)-5,6-bis(4-phenylsulfonic acid)-l,2,4-triazine], that selectively bind Fe(II). Determining Fe(II) as well as the total Fe after on-line reduction of Fe(III) to Fe(II) with ascorbic acid allows a kind of speciation.37 A drawback is that the selective complexing agents can shift the iron redox speciation in the sample. For example, several researchers have reported a tendency for ferrozine to reduce Fe(III) to Fe(II) under certain conditions.76 Most ferrozine methods involve sample acidification, which may also promote reduction of Fe(III) in the sample. Fe(II) is a transient species in most seawater environments and is rapidly oxidized to Fe(III) therefore, unacidified samples are required in order to maintain redox integrity.8 An alternative is to couple FIA with a chemiluminescence reaction.77-78... 

Micro flow control devices open new possibilities for the miniaturization of conventional chemical and biochemical analysis systems. The micro total analysis system (pTAS) including microfabricated detectors (e.g. silicon based chemical sensors, optical sensors), micro flow control devices and control/detec-tion circuits is a practical micro electro mechanical system (MEMS). pTAS realize very small necessary sample volume, fast response and the reduction of reagents which is very useful in chemical and medical analysis. Two approaches of monolithic and hybrid integration of these devices have been studied. Monolithic and hybrid types of flow injection analysis (FIA) systems were already demonstrated [4, 5]. The combination of the partly integrated components and discrete components is useful in many cases [6]. To fabricate such systems, bonding and assembling methods play very important roles [7]. 

Cheng, S.B., Skinner, C.D., Harrison, D.J., Integrated serial dilution on a microchip for immunoassay sample treatment and flow injection analysis. Micro Total Analysis Systems 98, Proceedings pTAS 98 Workshop, Banff, Canada, 13-16 Oct. 1998, 157-160. 

J. Ruzicka, Flow injection analysis. From test tube to integrated microconduits, Anal. Chem. 55 (1983) 1040A. 

J. Ruzicka, E.H. Flansen, Integrated microconduits for flow injection analysis, Anal. Chim. Acta 161 (1984) 1. 

Petersson B, Hansen E and Ruzicka J 1986 Enzymic assay by flow injection analysis with detection by chemiluminescence determination of glucose, creatinine, free cholesterol and lactic acid using an integrated FIA microconduit Anal. Lett. 19 649-65 Ruzicka J and Hansen E 1975 Row injection analysis. Part I. A new concept of fast continuous flow analysis Anal. Chim. Acta 78 145-57... 

The Integrated Biosensor Flow Injection Analysis Systems... 

B. A. Petersson, E. H. Hansen, and J. RdiiCka, Enzymatic Assay by Flow Injection Analysis with Detection by Chemiluminescence Determination of Glucose, Creatinine, Free Cholesterol and Lactic Acid Using an Integrated FIA Microconduit. Anal. Lett., 19 (1986) 649. 

Integrated sorption-detection units are based on the placement of an inert or active support in the flow cell of a nondestructive spectroscopic detector where the analytes or their reaction products are retained temporarily for sensing immediately after their elution. The equipment required to develop this type of sorption methodology is very simple and closely resembles that used in ordinary flow injection analysis (FIA) manifolds. The only difference lies in the replacement of the packed reactor located in the transport-reaction zone with a packed flow cell (usually photometric or fluorimetric) situated in the detector. 

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