• Analytical Science and Technology
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• v.8 no.1
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• pp.79-84
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• 1995

Ion-selective poly(vinyl chloride) membrane electrodes for the determination of the anticholinergic drug alverine in pure substances is described. Ion-pair complex of alverine with anionic counter ion acid red 97 is investigated as electroactive compound for the electrode membrane. On the optimal composition of membrane, its slope was 55.35mV/decade, relative standard deviation was 0.61 and lower limit of linear range was $1.0{\times}10^{-5}M$. The observed potentiometric selectivity coefficient was -2.625 toward methylephedrine and -2.216 toward histidine. We can got the stable potential at pH 7.0~4.0. Response time was 20~30 seconds for solutions${\leq}10^{-4}M$, about 10 seconds for solutions ${\geq}10^{-4}M$ of these compounds.

• Bulletin of the Korean Chemical Society
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• v.29 no.12
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• pp.2471-2476
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• 2008

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2229-2237
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• 2012

The two chelates based on calix[4]arene and thiacalix[4]arene have been synthesized and used as neutral ionophores for preparing PVC based membrane sensor selective to $Ho^{3+}$ ion. The addition of potassium tetrakis(4-chlorophenyl)borate (KTpClPB) and various plasticizers, viz., NDPE, o-NPOE, DOP, TEP and DOS have been found to improve significantly the performance of the sensors. The best performance was obtained with the sensor no. 6 having membrane of $L_2$ with composition (w/w) ionophore (2%): KTpClPB (4%): PVC (37%): NDPE (57%). This sensor exhibits Nernatian response with slope $21.10{\pm}0.3mV/decade$ of activity in the concentration range $3.0{\times}10^{-8}-1.0{\times}10^{-2}M\;Ho^{3+}\;ion$, with a detection limit of $1.0{\times}10^{-8}M$. The proposed sensor performs satisfactorily over a wide pH range of 2.8-10, with a fast response time (5 s). The sensor was also found to work successfully in partially non-aqueous media up to 25% (v/v) content of methanol, ethanol and acetonitrile, and can be used for a period of 4 months without any significant drift in potential. The electrode was also used for the determination of $Ho^{3+}$ ions in synthetic mixtures of different ions and the determination of the arsenate ion in different water samples.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.169-175
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• 2006

Potentiometric biosensor using flow injection analysis system was developed to determine citrate concentration in foods. Biosensor system consisted of sample injector, peristaltic pump, enzyme reactor, carbonate ion selective solid-state electrode, reference electrode, detector, and recorder. Enzyme reactor was prepared with immobilized citrate lyase and oxaloacetate decarboxylase. Carbonate ions produced through enzyme reactions of citrate were potentiometrically detected by ion selective electrode. Optimum conditions for biosensor system were investigated. Interference effect of major sugars and organic acids was less than 5% on citrate biosensor system. Citrate concentrations in fruit juices were determined by biosensor and gas chromatography. No significant difference was observed between two analytical methods. Results indicate citrate biosensor is useful in determining citrate concentration in foods.

• 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.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2722-2726
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• 2011

Plasticized poly(vinyl chloride), PVCs, with different membrane compositions tested for use in the construction of an ion-selective sensor for the determination dibucaine. A prepared membrane with dioctyl phthalate-PVC and ion-pair of N-(1-naphthyl)ethylenediamine dihydrochloride-tetraphenyl borate had a good potential to acts as a potentiometric sensor for the analysis of dibucaine. A linear relationship was obtained between potential and logC varying between $1.0{\times}10^{-6}$ and $1.0{\times}10^{-2}$ M dibucaine with a good repeatability and reproducibility. The sensor was applied for the determination of the drug in pharmaceuticals and biological fluids such as plasma and urine samples with satisfactory results. The drug electrode has also been used to study the interaction of bovine serum albumin (BSA) with dibucaine. The saturated quantities of dibucaine binding were 13.04, 5.30 and 9.70 mol/mol in 0.01, 0.02 and 0.1% of protein, respectively.

• YAKHAK HOEJI
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• v.45 no.1
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• pp.29-33
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• 2001

A method for the determination of anionic drug, mefenamate with ion-selective electrode using Fe(II)-1,10-phenanthroline chelate as a counter ion was developed. Benzyl nitrophenyl ether (BNPE) plasticized membrane was more selective and sensitive than the other tested membranes. This membrane electrode exhibits a linear response for 10$^{-2}$ M~5 $\times$ 10$^{-5}$ M of mefenamic acid with a slope of -61.4 mV/dec. in borate buffer solutions (pH 9.0). Potentiometric selectivity measurements revealed negligible interferences from various organic and ionorganic anions. Direct potentiometry and potentiometric titration method of mefenamic acid in capsule preparations are presented and compared.

• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.137-143
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• 1985

Construction of a liquid membrane type of cupric ion selective electrode and its application to the potentiometric titration have been studied. A liquid ion-exchange membrance was prepared by extracting Cu(II) in aqueous solution into 1-(2-pyridylazo)-2-naphthol/nitrobenzene. A Ag/AgCl internal reference electrode was dipped into the aqueous reference solution of $1.00 {\times} 10^{-3}M\;Cu(NO_3)_2$ buffered with HAc-NaAc buffer solution, which was in contact with the nitrobenzene extract. The electrode showed the nernstian response to Cu(II) in the concentration range from $1.00{\times} 10^{-6}$ to $1.00{\times} 10^{-3}$M. The most suitable ion-exchanger concentration in the liquid membrane was $1.00{\times} 10^{-4}$M. The selectivity coefficients of the electrode for the various metal cations were investigated. The electrode was applied to the potentiometric titration of Cu(II) with EDTA.

• Bulletin of the Korean Chemical Society
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• v.17 no.5
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• pp.405-407
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• 1996

• Bulletin of the Korean Chemical Society
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• v.16 no.3
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• pp.197-199
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• 1995