Diffusion Flow Injection Analysis Research Articles

An on‐line determination of chlorine dioxide using chlorophenol red by gas diffusion flow‐injection analysis

An on-line determination of chlorine dioxide (ClO2) in potable water using chlorophenol red (CPR) by gas diffusion flow-injection analysis (FIA) was investigated in the presence of various chlorinated species that can occur under normal water-treatment conditions. A gas diffusion membrane is used to separate the donor (sample) stream from the acceptor (detecting) stream (the donor stream transports the sample stream to the membrane separate device, and the acceptor stream collects all of the penetrated analytes and transports quantitatively to the detector) and makes it possible for this method to eliminate interference from metal ions, as well as other oxychlorinated compounds such as chlorite and chlorate. The system is more selective for chlorine dioxide than chlorine. The linear range of ClO2 concentration is 0–0.5 mg·mL−1 with a detection limit of 0.02 μg·mL−1 (S/N = 3) and a sampling frequency of 50 h−1. © 1999 John Wiley & Sons, Inc. Lab Robotics and Automation 11: 157–161, 1999

An on-line determination of chlorine dioxide using chlorophenol red by gas diffusion flow-injection analysis

An on-line determination of chlorine dioxide (ClO2) in potable water using chlorophenol red (CPR) by gas diffusion flow-injection analysis (FIA) was investigated in the presence of various chlorinated species that can occur under normal water-treatment conditions. A gas diffusion membrane is used to separate the donor (sample) stream from the acceptor (detecting) stream (the donor stream transports the sample stream to the membrane separate device, and the acceptor stream collects all of the penetrated analytes and transports quantitatively to the detector) and makes it possible for this method to eliminate interference from metal ions, as well as other oxychlorinated compounds such as chlorite and chlorate. The system is more selective for chlorine dioxide than chlorine. The linear range of ClO2 concentration is 0–0.5 mg·mL−1 with a detection limit of 0.02 μg·mL−1 (S/N = 3) and a sampling frequency of 50 h−1. © 1999 John Wiley & Sons, Inc. Lab Robotics and Automation 11: 157–161, 1999

Calibration methods for determination of ammonium and excess acid in Kjeldahl digests by flow injection analysis

Several modes of calibration for the determination of ammonium (protein) by gas diffusion flow injection analysis (FIA) in Kjeldahl sample solutions have been evaluated with the goal of reducing analytical variability caused by deviations in acid content. Univariate calibration based on peak area as a response function allows accurate and precise determination of the protein content only if small injection volumes, i.e., less than 80 μl, are used. No possibility to estimate the concentration of excess acid then exists. However, by using the entire FIA response curve (1098 data points) and partial least squares (PLS) calibration both protein and excess acid can be determined in one single run. The calibration set must be comprised of solutions covering both the expected protein and the excess acid concentration ranges. The method has been tested on feed samples. Typical values for the root mean square errors of prediction (RMSEP) were 0.8% for protein and 0.025 mol/l for sulphuric acid.

Determination of arsenic by hydride generation gas diffusion flow injection analysis with electrochemical detection

Hydride generation gas diffusion flow injection analysis with two different electrochemical detectors — conductometric or amperometric — has been investigated for the determination of arsenic. With amperometric detection, where a detection limit (signal-to-noise ratio = 3) of 0.01 mg 1 −1 As was achieved, the method was successfully applied to the determination of arsenic in contaminated soil samples. The technique is highly sensitive, accurate and precise, with low susceptibility to interferences, significant reagent and instrument economy, and affords the possibility of the development of a portable field instrument which could be used at a contaminated site.

Flow injection analysis chemiluminescence detection of residual ozone

Chemiluminescent reagents for the determination of residual ozone were compared. Each method was automated using gas diffusion flow injection analysis. The luminol method gave a four order of magnitude working range with an LOD of 0.008 mg O 3/l. The luminol method has better analytical characteristics than the standard colorimetric Indigo Blue methods

Reverse dual phase gas diffusion flow injection analysis

A flow injection gas diffusion system for gas acceptor to liquid donor stream, reverse dual phase gas diffusion flow injection analysis, has been demonstrated. Feasibility was shown with a carbon dioxide chemistry. A series of methods was investigated for hydrazine determinations. Using bromthymol blue indicator and a Celgard 2500 membrane a detection limit of 0.01 ppm v/v hydrazine was observed.

Indirect determination of bromide by diffusion flow injection analysis with amperometric detection

A rapid, indirect diffusion flow injection analysis (FIA) method with amperometric detection has been developed for the selective and sensitive determination of Br−. The method is based on permanganate oxidation of Br− to bromine. Bromine diffuses through a PTFE membrane and is quantified amperometrically at a platinum working electrode. Calibration graphs were linear up to the maximum concentration of Br− investigated (10.0 mmol/l). The precision of the technique was better than a relative standard deviation of 0.7% at 10.0 μmol/l, with a throughput of 30 samples per hour. The effects of temperature, acidity, working potential, composition of the reagent solution and interferents on the FIA signals were studied. The catalytic effect of Cl− on the permanganate oxidation of the analyte was utilized to lower the detection limit to 1 μmol/l (16 ng Br−). Similar detection limits were achieved by combining the effects of higher acidity (4.0 mol/l H2SO4) and elevated temperatures (40°C). The method was successfully applied to the determination of Br− in chloride and other reagents, as well as in natural waters.

Flow injection gas-diffusion method for preconcentration and determination of trace sulfide

A preconcentrating gas diffusion flow injection analysis (FIA) method with amperometric detection has been developed for selective determination of sulfide. The method is based on using the acceptor stream of the diffusion unit in a closed-loop, mobile (recirculating) mode for the accumulation of the analyte. In the analysis step the contents of the acceptor loop are injected into a sodium carbonate stream and are carried to the amperometric detector. The various flow patterns required for this method are regulated by a single eight-port rotary valve. The method developed has very low detection limits of 0.15 ..mu..g/L. The relative standard deviation for a 1 ..mu..g/L standard is 4%, and of the potential interferences tested, only cyanide had an effect.

Utilization of Dual Phase Gas Diffusion FIA with a Mass Spectrometer as a Detector

Abstract The coupling of dual phase gas diffusion flow injection analysis with mass spectrometry has been shown to be feasible. This combined technique offers a high degree of selectivity and sensitivity. This technique was developed to determine whether volatile mixed arsenic selenium hydrides are formed in dual phase gas diffusion flow injection analysis hydride generation.

Selective determination of chlorine dioxide using gas diffusion flow injection analysis

An automated absorbance technique for the determination of aqueous chlorine dioxide has been developed by utilizing gas diffusion flow injection analysis. A gas diffusion membrane is used to separate the donor (sampling) stream from the acceptor (detecting) stream. The absorbance of chlorine dioxide is monitored at 359 nm. The first method uses distilled water as the acceptor stream and gives a detection limit of 0.25 mg/L chlorine dioxide. This system is over 550 times more selective for chlorine dioxide than chlorine. To further minimize chlorine interference, oxalic acid is used in the acceptor stream. The detection limit for this system is 0.45 mg/L chlorine dioxide. This second system is over 5400 times more selective for chlorine dioxide than chlorine. Both methods show excellent selectivity for chlorine dioxide over iron and manganese compounds, as well as other oxychlorinated compounds such as chlorite and perchlorate ions. 18 references, 7 figures, 3 tables.

Residual aqueous ozone determination by gas diffusion flow injection analysis

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTResidual aqueous ozone determination by gas diffusion flow injection analysisMichael R. Straka, Gilbert. Gordon, and Gilbert E. PaceyCite this: Anal. Chem. 1985, 57, 9, 1799–1803Publication Date (Print):August 1, 1985Publication History Published online1 May 2002Published inissue 1 August 1985https://doi.org/10.1021/ac00286a004RIGHTS & PERMISSIONSArticle Views218Altmetric-Citations43LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts Get e-Alerts