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Although experiment and computer analysis of zone-circulating flow injection analysis (ZCFIA) data have been investigated, there are still some essential problems inherent to ZCFIA. Computer program of high dimensional modified simplex method was used for resolving peaks of ZCFIA damped response curves. Peaks are resolved on the basis of the criterion that each area of the peak surrounded by the...
The newly developed flow instrument, bypass trapped-flow analysis system (ByT-FAS), was used to perform enzyme assays and generate data for evaluation of an enzyme's kinetic parameters. The enzyme assay was yeast hexokinase coupled to glucose-6-phosphate dehydrogenase and the production of reduced NADPH was monitored fluorometrically. The kinetic parameters of hexokinase that were evaluated with...
A simple flow injection analysis (FIA) system for residual chlorine in tap water has been developed by using a Pb(II) ion-selective electrode (ISE) detector. The method is based on a specific response of the Pb(II)-ISE to residual chlorine. The FIA system consists of a millivolt meter, a peristaltic pump, a Pb(II)-ISE detector and a recorder. A linear working curve between peak height and concentration...
The field of flow injection analysis (FIA) is growing rapidly because much applied research is being conducted around the world. This creates a great need for information dissemination across the globe to keep researchers up to date on current research trends. With the internet becoming the tool for global communication, it seems appropriate that support of the growth in FIA should be via this medium...
A simple flow injection spectrophotometric method for the determination of anionic surfactants in river water was studied. A three-channel flow system was assembled. The distilled water as a carrier and 5 10 -5 mol l -1 Malachite Green (MG) dissolved in 0.1 mol l -1 CH 3 COONa-CH 3 COOH buffer solution (pH 5) were delivered at 1.94 ml min...
A new catalytic method for the determination of silver(I) was developed based on a metal exchange reaction between ethylenediaminetetraacetatomercury(II) (Hg II -EDTA) in the aqueous phase and bis(diethyldithiocarbamato)copper(II) (Cu II -DDTC) in the organic phase. This exchange reaction (Cu II -DDTC org + Hg II -EDTA → Hg ...
A new semi-automated flow analysis system called bypass trapped flow analysis system (ByT-FAS), is described. ByT-FAS gives an analyst the ability to inject sample and reagent volumes of 50-100 μl or more, into flowing streams and attain physical steady state concentrations in the detection cell within a few seconds (? 1 min) after the insertion of the sample and/or reagent. After physical steady...
A new type of amperometric biosensor based on immobilised acetylcholine esterase was designed and constructed. The enzyme was immobilised on a flow-through working electrode, which was prepared from reticulated vitreous carbon (RVC) or from a composite material consisting of RVC and superporous agarose. The sensor was operated in FIA mode using acetylthiocholine as a substrate. The sensor responded...
A highly sensitive potentiometric flow injection determination of amylase activity was carried out, utilizing a redox reaction of hexacyanoferrate(III) in alkaline media with reducing sugar as product of the enzymatic hydrolysis reaction of starch with amylase. The analytical method is based on the potential change detection of a flow-through type redox electrode detector due to the composition change...
A sensitive and rapid method is presented for the determination of vanadium at ng to sub-ng ml -1 levels in natural waters, in which in-line preconcentration/separation is directly coupled with catalytic detection of vanadium in a flow-injection system. Vanadium was adsorbed on a small column packed with Sephadex G-25 gel and desorbed with a small volume of 0.010 M HCl. The catalytic...
Bypass trapped flow analysis system (ByT-FAS) is a new trapped flow apparatus designed to perform chemical measurements with flow injection systems at physical steady state using small volumes (10-150 μl) of injected sample and reagent. We have used a micro-volume version of ByT-FAS instrumentation with a chemiluminescent detection system to quantitate the protein transcription levels of transformed...
An on-line flow injection-hydride generation/atomic absorption spectrometry method was developed for the preconcentration and selective determination of inorganic arsenic [As(III) and As(V)] and its methylated species. The separation of the arsenic species was performed by an automated pH-selective arsines generation technique, using sodium tetrahydroborate(III) as reductant. Each arsine was cryogenically...
On-line gas diffusion has been coupled to a capillary electrophoresis system (CE) via a specially designed interface. The sample is merged with a modifying solution, e.g., a strong acid, in a flow system to transform the analytes of interest into their respective gaseous forms. These transformed, gaseous analytes permeate through a PTFE membrane into an acceptor stream comprising of a tris-buffer...
The viability of electrodialysis (ED) for the enhancement of mass transfer through passive neutral membranes in a flow injection system was investigated. A Spectrapore and Technicon type C membrane were evaluated using chloride anions as analyte. Both membranes showed an increase in mass transfer and the proposed electrodialyser/FIA system was applied for the determination of chloride in industrial...
Mesoporous SnO 2 with high surface areas were synthesized using a cationic surfactant (N-cetyl-N,N,N-trimethylammonium bromide) as a synthetic template. Acidity of the starting synthesis slurry was used as one of the controlling parameters for the synthesis. After the SnO 2 was synthesized at pH 7.15, it was calcined at 723 K for 10 h in air. It had a BET surface area of 156.8 m ...
The degree of deacetylation (DD) is increasingly becoming an important property for chitosan, as it determines how the biopolymer can be applied. Therefore, a simple, rapid and reliable method of determining the DD for chitosan is essential. In this report, the DD of chitosan was determined by nuclear magnetic resonance (NMR), linear potentiometric titration (LPT), ninhydrin test and first derivative...
Both hydrophobic interaction chromatography (HIC) and ion-exchange chromatography (IEC) are commonly used for the purification of proteins as their mild elution conditions preclude the dangers of denaturation. Of the two methods, IEC which fractionates proteins on the basis of charge differences, exhibits a higher selectivity. In the case of the metallothionein (MT) proteins, the charge states of...
We demonstrate the use of membrane preconcentration capillary electrophoresis tandem mass spectrometry (mPC-CE-MS/MS) for sequencing peptides at the sub-100 femtomole level. In particular by loading the mPC-CE cartridge off-line with a pressurized bomb apparatus, 100 μl solutions can be loaded in <5 min. Furthermore, mPC-CE-MS in conjunction with on-line transient isotachophoresis carried out in...
Mixed chloroform solution of Polysiloxane PS-264 and stearic acid was made into multilayer Langmuir-Blodgett (LB) films on the surface of quartz crystal microbalance (QCM). The condition for forming mixed multilayer LB films is discussed in this paper. In addition, PS-264, stearic acid and their mixture (molar ratio 1:1) were coated on the surface of QCM sensors by a spin coating method. The above...
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