• Title, Summary, Keyword: ion-selective electrode

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Electrosorption of Uranium Ions in Liquid Waste

  • Lee, Hye-Young;Jung, Chong-Hun;Oh, Won-Zin;Park, Jin-Ho;Shul, Yong-Gun
    • Carbon letters
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    • v.4 no.2
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    • pp.64-68
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    • 2003
  • A study on the electrosorption of uranium ions onto a porous activated carbon fiber (ACF) was performed to treat uraniumcontaining lagoon sludge. The result of the continuous flow-through cell electrosorption experiments showed that the applied negative potential increased the adsorption kinetics and capacity in comparison to the open-circuit potential (OCP) adsorption for uranium ions. Effective U(VI) removal is accomplished when a negative potential is applied to the activated carbon fiber (ACF) electrode. For a feed concentration of 100 mg/L, the concentration of U(VI) in the cell effluent is reduced to less than 1 mg/L. The selective removal of uranium ions from electrolyte was possible by the electrosorption process.

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Development of Portable Electronic Tongue using Fuzzy clustering algorithm (Fuzzy Clustering 알고리즘을 이용한 휴대용 전자 혀 개발)

  • Kim, Joeng-Do;Ham, Yu-Kyung;Jung, Woo-Suk;Jung, Young-Chang
    • Proceedings of the KIEE Conference
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    • pp.602-604
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    • 2004
  • A portable electronic tongue(E-Tongue) system using an array of ion-selective electrode(ISE) and personal digital assistants(PDA) for recognizing and analyzing food and drink have been designed. By the employment of PDA, the complex algorithm such as fuzzy c-means algorithm(FCMA) could be used in E-Tongue, FCMA could iteratively solve the cluster centers of pre-determined standard patterns. And the membership between the standard patterns and unknown pattern could be analyzed easily by the present E-Tongue combined with PDA.

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Design of a Portable Electronic Tongue System using Fuzzy C-Means Algorithm (Fuzzy C-Means Algorithm을 이용한 휴대용 전자혀 시스템 설계)

  • Kim, Jeong-Do;Kim, Dong-Jin;Ham, Yu-Kyung;Jung, Young-Chang;Yoon, Chul-Oh
    • Journal of Sensor Science and Technology
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    • v.13 no.6
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    • pp.446-453
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    • 2004
  • A portable electronic tongue (E-Tongue) system using an array of ion-selective electrode (ISE) and personal digital assistants (PDA) for recognizing and analyzing food and drink have been designed. By the employment of PDA, the complex algorithm such as fuzzy c-means algorithm (FCMA) could be used in E-Tongue, PUMA could iteratively solve the cluster centers of pre-determined standard patterns. And the membership between the standard patterns and unknown pattern could be analyzed easily by the present E-Tongue combined with PDA.

Development of Electronic Tongue System Using Fuzzy C-Means Algorithm Combined to PCA Method (PCA와 결합된 Fuzzy C-Means 알고리즘을 이용한 전자 혀 시스템 개발)

  • Jung Woo Suk;Hong Chul Ho;Kim Jeong Do
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.2
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    • pp.109-116
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    • 2005
  • In this paper, we investigate the visual and quantitative analysis at the same time with an electronic tongue(e-tongue) system using an array of ISE(ion-selective electrode). We apply the FCM(fuzzy c-means) algorithm combined with PCA(principal component analysis), which can be reduced multi-dimensional data to third-dimensional data, to classify data patterns detected by E-Tongue system. The proposed technique can be designed to solve the cluster centers and membership grade of patterns combined with the output results obtained by PCA method. According to the proposed technique, the membership grade of unknown pattern, which does not shown previously can be determined and analyzed visually. Conclusionally, the relationship between the standard patterns and unknown pattern can be easily analyzed. Throughout the experimental trials, the proposed technique has been confirmed using developed E-Tongue system.

Discriminant Analysis of Marketed Liquor by a Multi-channel Taste Evaluation System

  • Kim, Nam-Soo
    • Food Science and Biotechnology
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    • v.14 no.4
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    • pp.554-557
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    • 2005
  • As a device for taste sensation, an 8-channel taste evaluation system was prepared and applied for discriminant analysis of marketed liquor. The biomimetic polymer membranes for the system were prepared through a casting procedure by employing polyvinyl chloride, bis (2-ethylhexyl)sebacate as plasticizer and electroactive materials such as valinomycin in the ratio of 33:66:1, and were separately attached over the sensitive area of ion-selective electrodes to construct the corresponding taste sensor array. The sensor array in conjunction with a double junction reference electrode was connected to a high-input impedance amplifier and the amplified sensor signals were interfaced to a personal computer via an A/D converter. When the signal data from the sensor array for 3 groups of marketed liquor like Maesilju, Soju and beer were analyzed by principal component analysis after normalization, it was observed that the 1st, 2nd and 3rd principal component were responsible for most of the total data variance, and the analyzed liquor samples were discriminated well in 2 dimensional principal component planes composed of the 1st-2nd and the 1st-3rd principal component.

Response Mechanism of 5, 10, 15, 20-tetraphenyl(porphyrinato) Manganase(III) chloride-Based Ion-Selective Membranes (망간포르피린을 함유한 고분자형 이온선택성 막전극의 감응 메카니즘)

  • Hong, Young Ki;Kang, You Ra;Shin, Dae Ho;Shin, Doo Soon;Cha, Geun Sig;Nam, Hakhyun
    • Analytical Science and Technology
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    • v.9 no.3
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    • pp.270-278
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    • 1996
  • Response mechanism for the chloride-selective membrane doped with 5, 10, 15, 20-tetraphenyl(porphyrinato)manganase(III) chloride(Mn(TPP)Cl) in PVC/DOS matrix is proposed by examining the visible spectra of the corresponding optode membrane. The visible spectra of Mn(TPP)Cl-doped membrane placed in aqueous solution show that the chloride ligand is easily replaced with water molecule. When other halogen ions, such as $F^-$, $Br^-$ and $I^-$, are added to the sample solution, they replace the water ligand, exhibiting distinctive change in the Soret band of Mn(TPP). On the other hand, bulky anions, such as SCN and salicylate, do not form a bond with the central metal. These results suggests that the potentiometric response of Mn(TPP)-based membrane results either from the ligand exchange (water with halides) at the central metal or from the counter ion exchange (chlorides with bulky lipophilic anions) around the positively charged porphyrin molecule in membrane phase. It was also noted that both hydration enthalpies of anions and their binding constants to Mn(TPP) play critical role in determining the potentiometric selectivity pattern of the membrane.

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Development of Extracting Solution for Soil Chemical Analysis Suitable to Integrated Ion-selective Micro-electrodes (집적형 이온선택성 미세전극 센서에 적합한 토양화학 분석용 침출액 종 개발)

  • Shin, Kook-Sik;Lim, Woo-Jin;Lee, Sang Eun;Lee, Jae Seon;Cha, Geun Sig
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.6
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    • pp.513-521
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    • 2009
  • The primary goal of this research was to develop an optimized analytical procedure for soil analysis based on ion-selective microelectrodes for agricultural purposes, which can perform on-site measurement of various ions in soil easily and rapidly. For the simple and rapid on-site diagnosis, an analysis of soil chemicals was performed employing a multicomponent-in-situ-extractant and an evaluation of ionselective microelectrodes were conducted through the regressive correlation method with a standard analytical approach widely employed in this area. Examination of sensor responses between various soil nutrient extractants revealed that 0.01M HCl and 1M LiCl provided the most ideal Nernstian response. However, 1M LiCl deteriorated the selective response for analytes due to high concentration (1M) of lithium cation. Thus, employing either 0.1M HCl as an extractant followed by 10 times dilution, or 0.01M HCl as an extractant without further dilution was chosen as the optimal extractant composition. A study of regressive correlation between results from ion-selective microelectrodes and those from the standard analytical procedure showed that analyses of $K^+$, $Na^+$, $Ca^{2+}$, and $NO_3{^-}$ showed the excellent consistency between two methods. However, the response for $NH_4{^+}$ suffered the severe interference from $K^+$. In addition, the selectivity for $Mg^{2+}$ over $Ca^{2+}$ was not sufficient enough since available ionophores developed so far do not provide such a high selectivity for $Mg^{2+}$. Therefore, as an agricultural on-site diagnostic instrument, the device in development requires further research on $NH_4{^+}$ analysis in the soil sample, development of $Mg^{2+}$-selective ionophore, and more detailed study focused on potassium, one of the most important plant nutrients.

Comparison Study of AAS and ISE Method in the Lithium Analysis of Serum and Urine (혈액 및 소변의 Lithium치 측정에 있어서 AAS법과 ISE법의 비교)

  • Lee, Soo-In;Lee, Chae-Hoon;Kim, Kyung-Dong;Kim, Chung-Sook
    • Yeungnam University Journal of Medicine
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    • v.10 no.2
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    • pp.409-416
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    • 1993
  • In the method for lithium (Li) analysis, flame emission photometry and atomic absorption spectrophotometry (AAS) have been used most frequently. In addition, lithium can be analyzed by ion-selective electrode (ISE) or fluorscence polarization immunoassay. We evaluated the comparison between AAS method based on the principle of absorption of light at 670.8 nm by Li and ISE method based on the principle of voltage difference generated by Li in contact with lithium ionophore. We compared with those obtained by AAS (AA/AE Spectrophotometer 551, Instrumentation Laboratory Co.) and ISE(CSYNCHRON EL-ISE, Beckman Co.) in the serum and urine of 6 patients and evaluated time-related changes of serum lithium concentration after dosing in both methods. The results are summarized as follows : 1. In within-run precision study for lithium concentration, coefficient variations (CVs, %) ranged from 1.34 to 2.17 for AAS and from 0.34 to 0.85 for ISE method. In between-run precision study for lithium concentration, CVs ranged from 1.23 to 1.72 for AAS and from 0.61 to 1.38 for ISE method. 2. The correlation study between AAS and ISE method resulted in Y=0.946X+0.137 (N=32, r=0.933, X=AAS, Y=ISE) for serum lithium and Y=1.092X+0.977 (N=28, r=0.943, X=AAS, Y=ISE) for urine lithium. 3. Time-related changes of serum lithium concentration in both AAS and ISE method resulted in peak serum levels about 2 hours after dosing and then rapidly decreased after the peak serum level and finally arrived at nearly initial levels about 9 hours after dosing. 4. The reference range of serum lithium was found as undetectable level for both AAS and ISE method and the reference range of urine lithium to the urine creatinine was 0-0.00014 mmol/mg(mean 0.00002 mmol/mg) for AAS method.

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Electronic Tongue Composed of Mini-Electrode Array in Flow Cell (소형전극 어레이로 구성한 흐름계형 전자혀)

  • Shim, Jun Ho;Shim, Jae Hoon;Seo, Sung Seok;Oh, Hyun Joon;Han, Jong Ho;Nam, Hakhyun;Cha, Geun Sig
    • Analytical Science and Technology
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    • v.17 no.3
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    • pp.217-224
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    • 2004
  • A taste sensor system composed of mini electrode array was built in a flow cell. Potentiometric signals from 9 electrodes were collected for drinking waters and alcoholic beverages which were diluted in a low concentration buffer solution (0.005 M Tris-$H_2SO_4$ pH 7.2) for the measurement. The measured results were treated with the principal component analysis (PCA), and grouped on a two or three dimensional PCA coordinate to discriminate the tastes of each beverage. It is demonstrated that the taste sensor system of this work may be used for the quality control of beverages in production or the examination of their taste variation in the market.

Effect of Ultrasonic Pretreatment on Analysis of Potassium Ion in Human Urine Using 15-Crown-5-Anthracene-based Membrane (15-Crown-5-Anthracene 막을 이용한 요 중의 칼륨이온 분석에 미치는 초음파 전처리의 효과)

  • Lee, Ji-Young;Chang, Hye-Young;Bae, Zun-Ung
    • Journal of the Korean Chemical Society
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    • v.47 no.1
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    • pp.13-18
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    • 2003
  • The effect of ultrasonic decomposition was introduced to develop a pretreatment method for the analysis of potassium ion in human urine by potentiometry. N-(4’-benzo-15-crown-5)-anthracene-9-imine, which has a good selectivity coefficient for potassium against ammonium, was used as an ion-selective material for the determination of potassium in urine with relatively high concentration of $NH_4{^+}$. Protenis in urine be removed by 85.1% when the sample acidified with 1.0 M $HNO_3$ was preteated for 100 s by sonication. Potential response of the membrane electrode in the pretreated urine had a slope of 54.6(${\pm}0.2,\;n=5$) mV/decade over the linear range of log $[K^+]$=-5~-1(r=0.9997). When an oxidant, $H_2O_2$, was addwd to the urine sonicated with $HNO_3$, the deproteinization increased 10% more than that in case if only $HNO_3$ and then the maximum ratio of ca. 95% was obtained. Moreover, the Nernstian slope for $K^+$ added to the urinary sample increased to 56.7(${\pm}0.1,\;n=3$) mV/decade. When the calibration curves were measured, the slopes did not vary even after the electrode was successively used 20 times with ultrasonic cleaning. The results showed that an ultrasonic pretreatment method provides simplicity in use, reduced treatment time and improved potentiometric characteristics of the membrane as the method effectively removes ca. 95% of proteins in urine.