• Analytical Science and Technology
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• v.14 no.6
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• pp.510-515
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• 2001

There has been an increasing need for analytical methods of dissolved total iron (tFe) that are highly sensitive, rapid, inexpensive and simple for environmental samples. A sensitive flow injection analysis (FIA) method for determining the concentration of tFe in environmental samples was developed. The proposed method required 10 minutes and only $500{\mu}L$ of sample for and analysis. The standard deviation was 5.0% at $0.5{\mu}gL^{-1}$ (n=6), and the detection limit was $0.075{\mu}gL^{-1}$. The developed method was applied to environmental samples such as tap water, mineral water, rain, snow and cloud water. Since this FIA system was free form interferences of coexisting ions commonly found in samples, sub-${\mu}gL^{-1}$ level of tFe could be easily determined without further preconcentration and separation.

• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.430-437
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• 1999

The determination of total chlorine residuals in drinking water by flow injection analysis(FIA) with iodometric UV detection was investigated. The pH of the acid stream, the concentration of the iodide ion,the length of the mixing and reaction coils, the injection sample size, and flowrate were optimized as parameters for determining total chlorine residuals by FIA method. lodide was selectively oxidized to iodine by hypochlorite at pH 8.3 Ethylenediamine as masking agent for masking interference ions from the sample was given the best efficency. Calibration curve presented linear range of 0.03-3 mg/L for hypochlorite ion with a correlation coefficient of 0.999 or better. The detection limit was found to be 0.007 mg/L for hypochlorite ion. Under these analytical conditions, total chlorine residuals in several tap water sampled in the city of Jeonju were analyzed.

• KSBB Journal
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• v.19 no.3
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• pp.241-244
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• 2004

An automated flow injection analysis apparatus manufactured economically was used in the automatic measurement of E. col growth in shake-flask culture of nutrient broth. The detailed measurement of whole growth was possible at intervals of 10 minutes by the automatic measurement system which adopted the sterilized nutrient broth as a carrier solution. Using distilled water as a carrier solution showed less accurate results than nutrient broth.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.241-243
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• 2001

On-line monitoring technique for the concentration of lactate by a FIA(Flow Injection Analysis) system was studied. The lactate oxidase(LOD) was immboilized on VA-Epoxy carrier and integrated into the FIA system. The pH, buffer flow rate and temperature for the LOD-FIA were optimized, and the effects of salts and metabolites dissolved in the sample on the activity of immobilized enzyme were investigated. The LOD-FIA has been applied to monitor the concentrations of lactate in a simulated bioprocess. The on-line monitoring data by the LOD-FIA agreed with the off-line data measured by a fluorescence spectroscopy well.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3437-3442
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• 2011

An on-line flow injection analysis with dual pre-concentration method was developed to determine the ultra trace tri and hexavalent chromium in water. In this system, the cation and anion pre-concentration columns were combined with a 10-port injection valve and then used to separate and concentrate Cr (III) and Cr (VI) selectively. The two species of concentrated chromium were sequentially eluted and determined by using HCl-KCl buffer of pH 1.8 as an eluent. Cr (III) was oxidized by hydrogen peroxide to Cr (VI). It was detected spectrophotometrically at 548 nm by complexation with DPC (diphenylcarbazide). Several factors such as concentration of $H_2O_2$, DPC and coil length in reaction condition were optimized. The linear range for Cr (III) and Cr (VI) was 0.1-50 ${\mu}g$/L. The limit of detections ($3{\sigma}$) of Cr (III) and Cr (VI) were 52 ng/L and 44 ng/L under the optimized FIA system, and their recoveries 98% and 103%, respectively. This method was applied to analyze contamination level of chromium species in tap water, groundwater and bottled water.

• KSBB Journal
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• v.22 no.2
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• pp.84-90
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• 2007

Trehalose is non-reducing disaccharide which is found in bacteria, fungi, plants and insects. Trehalose has been determined by several analysis methods. To monitor the concentrations of trehalose in a process, enzymatic methods have more advantage over others, e.g. more specific. In this work, trehalase was immobilized on VA-epoxy polymer and applied to FIA systems. The behaviours of these FIA systems were characterized and used to monitor the trehalose concentrations. Use of optical detection technique was chosen for trehalose-FIA system. On-line monitoring data and off-line data were measured by HPLC.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.730-734
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• 2005

Flow injection analysis (FIA) system was developed to monitor glucose concentrations in biotechnological processes. A fiber optic oxygen sensor was used to determine consumption of oxygen concentration by reaction of immobilized glucose oxidase (GOD). The GOD was immobilized on VA-Epoxy carrier and integrated into FIA system. A calibration curve for glucose was obtained in the range of 0.5 $g/L{\sim}3.0$ g/L.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.36-42
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• 1998

Ion-selective eleltrodes(ISEs) are simple electrodechemical devices for the direct measurement of ions in the samples. A novel potentiometric biosensor for the determination of L-Malate or D-isocitrate has been developed by using CO2-3 -ISE-FIA system was composed of a pump, an injector, a malic enzyme or isocitric dehydrogenase enzyme reactor, a CO2-3 -ISE, a pH/mV meter, and an integrater. The various factors, such as buffer capacity types of plstericizer and polymer, were optimized for the CO2-3 selectivity. In this novel CO2-3 --ISE-FIA system, the potential difference due to the amount of CO2-3 produced from each enzyme reaction was proportional to the amount of L-malate or D-isocitrate.

• Journal of Biosystems Engineering
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• v.33 no.4
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• pp.276-281
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• 2008

A flow injection analysis method (FIA), which analyzes sample conditions after injecting a sample and reagents into a continuous stream, are recognized as the most adequate analyzing method according to the increase of sampling frequency, the decrease of measuring time and the diversity of measuring targets. Specially, the FIA is considered to be used effectively for the control of a fermentation process to produce fermentation food and useful microbial production by activation of a fermentation industry for development of biological materials. In this study, a flow injection analysis sensor unit was developed for on-line monitoring of the fermentation process. The performance was verified by on-line measuring the concentration of glucose of the fermentation process of wine. The glucose concentrations of the samples were measured every 12 hours during the whole fermentation process and compared with those by a HPLC. The concentration relative errors of glucose on the fermentation process of wine showed below 30% within 72 hours and over 50% after the 72 hours. The sensor unit had potential to on-line monitoring of the fermentation process but some problems to overcome for an commercial application.

• Journal of the Korean Chemical Society
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• v.41 no.5
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• pp.256-265
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• 1997

A rapid and sequential method was studied, which can determine nitrite, nitrate and ammonium ion in soil or water samples with flow injection analysis. Geometric factors including injection volume, length of the reaction coil and flow rate of carrier solution were investigated prior to sample measurement. Nitrite was determined at 540 nm by Griess reaction producing azo dye between N-(1-naphthylethylenediamine dihydrochloride) and sulfanilamide. Nitrate was also measured under the help of reduction mechanism toward nitrite with hydrazine. Ammonium was analyzed at 440 nm with Nessler's reagent. At the optimum condition, the detection limit(S/N=3) has been shown 0.1 ㎍/mL N(NO2-), 0.4 ㎍/mL N(NO3-) and 0.3 ㎍/mL N(NH4+) respectively. The results measured by colorimetry, ion chromatography and FIA were compared showing 80%-125% reasonable match each other. Injection throughput rate could be performed better than 30 times per hour.