• Journal of Biosystems Engineering
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• 제32권1호
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• pp.37-43
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• 2007

This study was carried out to investigate the applicability of PVC membrane-based ion-selective electrodes for macronutrients (K, Ca, and N) by measuring of potassium, calcium, nitrate ions in hydroponic nutrient solution. The capabilities of two ion-selective membranes with varying chemical compositions for each ion were evaluated in terms of sensitivity, selectivity, and lifetime to choose sensing elements suitable for measuring typical ranges of nutrient concentrations in hydroponic solutions. The selected calcium and nitrate ion-selective membranes showed effectively sensitive responses to calcium and nitrate ions with lifetimes of 25 and 15 days, respectively. The addition of a cation additive to the potassium membrane cocktail allowed its sensitivity to be increased whereas its lifetime was reduced from 30 days to 10 days.

• Bulletin of the Korean Chemical Society
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• 제16권3호
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• pp.221-226
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• 1995

A method for determining nitrate in post treatment chromium plating solutions with PVC-based nitrate-selective electrodes is described. PVC-based nitrate-selective membranes which contain TDMANO3 ion-exchanger in PVC/NPOE, PVC/DOA or PVC/DBP matrices, and a commercially available Corning electrode (No. 476134) have been compared in respect of their detection limits, response slopes, selectivities at various pHs, and dynamic response to the hydrochromate ion in basic condition. The PVC/DBP/TDMANO3 membrane electrode was chosen as the ISE detector for the determination of nitrate in the presence of hydrochromate interference. The amount of nitrate in real post treatment chromium plating solution could be determined successfully with this electrode in both static and flow-injection measurements when the sample was properly diluted with an alkaline buffer.

• Journal of Yeungnam Medical Science
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• 제10권2호
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• pp.409-416
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• 1993

이상에서와 같이 lithium치의 측정에 있어서 본 병원에서 기존 이용하던 AAS법이나 ISE법 모두 정밀도나 직선성 평가에 있어 비교적 좋았으나, 정밀도(재현성)에 있어서 ISE법이 AAS법보다 더 우수한 것으로 나왔고 ISE법의 경우 측정방법이 매우 간편하였다. 그러나 ISE법에 의한 혈중 측정치가 AAS법에 의한 것보다 다소 높게 나타났으며, ISE법이 AAS법에 비하여 분석 최하한치가 더 높아 예민도는 상대적으로 낮았다.

• Journal of Biosystems Engineering
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• 제32권5호
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• pp.348-353
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• 2007

A solid state ion sensor module has been developed and evaluated for hydroponic nutrients analysis. The sensor module consisted of five ion-selective electrodes (ISE) fabricated by screen-printing technology. The electrochemical responses of ion sensors for nitrate, ammonium, potassium, calcium, and pH were measured with specially designed 7-channel low voltage signal transducers. The analytical characteristics of the sensors were comparable with those of conventional ISE sensors. The solid state ion sensors exhibit linear relationships over five concentration decades. Detection limit of the sensors were $5.6{\times}10^{-5}{\sim}1.6{\times}10^{-7}M$ depends on ions. Performance test results showed that relative errors of measured ion concentrations were less than 5% for $NO_3{^-},\;K^+,\;Ca^{2+}$ ion, and pH. The concentration of $NO_3{^-},\;NH_4{^+},\;K^+,\;Ca^{2+}$, and pH ion in standard solution and nutrient solutions could be determined by direct potentiometric measurements without any conditioning before measurements.

• 대한화학회지
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• 제55권1호
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• pp.63-69
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• 2011

이 작업은 수송체로서 N,N'-bis(2-hydroxybenzyl)-1,3-diaminopropane (L1)과 N,N'-bis(2-hydroxybenzyl)-2,2-dimethyl-1,3-diaminopropane (L2)에 기초한 $Ag^+$ 이온-선택 전극의 제조, 개발 그리고 전압반응에 대해 토의한다. $Ag^+$에 대하여 L1에 기초한 전극은 58.7 mV/dec에 도달하는 안정한 Nernst에 가까운 기울기와 $1.0{\times}10^{-6}M$의 검출한계를 갖는 등급의 최소 다섯가지 순서의 선형범위에서 최적의 전압 반응 특징을 보이는 것을 나타낸다. 제안된 전극은 다른 테스트한 양이온과 비교하여 $Ag^+$에 우위의 선택성을 보였다. 훌륭한 전압 분석적 특징은 중요한 진짜 샘플에서 은의 순도분석의 성공적인 응용을 이끌 것이다. 그리고 그것은 제안된 $Ag^+$-ISE가 측정 능력의 중요한 진보를 보여준다는 것을 나타내고 있다. 그러나 L2에 기초한 전극에 대해서는, 약한 전압 반응 특징들이 전체 실험 과정에서 관측되었다.

• 전기화학회지
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• 제9권3호
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• pp.132-134
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• 2006

본 연구에서는 테트라싸이크린 항생제를 양이온선택성 전극의 담체로 사용한 막전극을 제작하고 알칼리 및 알칼리 토금속에 적용하여 전위차 감응도를 조사하였다. 제작된 전극은 지용성 첨가제의 유무와 관계없이 $Ca^{2+}$ 이온에 대해서 거의 이상적인 전위차 감응도를 나타내었다. 또한 $Mg^{2+}$를 제외한 다른 양이온에도 이상적인 네른스트값에 80% 이상의 감응도와 $10^{-5}$ 이하의 검출한계를 나타내었다. 수명, 감응시간, 재현성 등도 이온선택성 전극에 응용하기에 문제가 없었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.153-153
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• 2022

There is a growing need to develop ion sensors for agriculture. As a result, several technologies have been developed, such as colorimetry, spectrophotometry, and ion-selective electrode (ISE). Among them, ISE has some advantages compared to others. First, it does not require pre-treatment processes and expensive equipment. Second, it is possible for the portable detection system by introducing small-sized electrodes. Finally, real-time and multiple detections of several ions are pursued. It is well-known that N, P, and K nutrients are critical for crop growth. With the development of agriculture techniques, the importance of soil nutrient analysis has attracted much attention for cost-effective and eco-friendly agriculture. Among several issues, minimizing the use of fertilizers is significant through quantitative analysis of soil nutrients. As a result, it is highly important to analyze certain nutrients, such as N (ammonium ion, nitrate ion, nitrite ion), P (dihydrogen phosphate ion, monohydrogen phosphate ion), and K (potassium ion). Therefore, developing sensors for accurate analysis of soil nutrients is highly desired. n this study, several ISEs have been fabricated to detect N, P, and K. Their performance has been intensively studied, such as sensitivity, selectivity coefficient, and concentration range, and compared with commercialized ISEs. In addition, preliminary tests on the in-situ N, P, and K monitoring have been conducted inside the soil.

• 한국안전학회지
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• 제6권4호
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• pp.13-20
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• 1991

Ion-selective electrode responsive to the thiocynate ion prepared by using the quaternary ammonium salts as a active material and PVC as a membrane matrix. The effect of chemical structure and composition of active material, and the membrane thickness on the linear response. the detection limit, and Nernstian slope of the electrode studied. Under the above optimum conditions of membrane, the effect of pH and the selectivity coefficients to various interfering anions were compared and investigated. It was concluded that the functions of thiocynate ion-selective electrode(ISE) were closely related to the chemical structure of the quaternary ammonium salts. The linear response, and the detection limit of the electrode potential increased with the increase of the carbon chain length of the alkyl group in the quaternary ammonium salts in the ascending order of Aliquat 336T, TOAT, TDAT, and TDDAT. The optimum membrane thickness was 0.3mm. The electrode characteristics was better with the decrease of the concentration of active material, and the best concentration was 3 weight percent. The membrane potential was independent of the pH variation in the region from pH 2 to 12. The order of the selectivity coefficients is as follows：Cl $O_4$$^{[-10]}$ ＞ $I^{[-10]}$ ＞N $O_3$$^{[-10]}$ ＞B $r^{[-10]}$ ＞ $F^{[-10]}$ ＞C $l^{[-10]}$ ＞O $A_{c}$ $^{[-10]}$ 〓S $O_4$$^{2-}$.

• 한국식품영양학회지
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• 제29권1호
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• pp.27-32
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• 2016

The purpose of this study was to measure concentrations of $K^+$, $Na^+$, $Cl^-$ by ionometer with check salt strip, simple salimeter and Ion-selective electrode (ISE) and compare the results of each mensuration; furthermore, the possibility of inferring the $Na^+$ concentration from $Cl^-$ concentration of urine and the impact of $K^+$ on the concentration of each ion was examined. The results showed that ISE determined $Na^+$ and $Cl^-$ concentrations in the urine are highly interrelated (R=0.9039); in addition, concentrations of $Cl^-$, measured with strip and ISE from urine are highly interrelated (R=0.9338). The concentration of $Na^+$ in urine, inferred by measuring $Cl^-$ concentration with strip, has a high relationship (R=0.8580) with the concentration of $Na^+$ in urine, measured by ISE. The results of our study will increase awareness of $Na^+$ intake and the utility of check salt strip, as well as the possibility of inferred $Na^+$ concentration from measures of $Cl^-$ concentration as a screening test for reducing sodium intake.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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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.