• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.523-523
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• 2003

The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol＇n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol＇n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.524-532
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• 2003

The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol＇n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol＇n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.

• Journal of the Korean institute of surface engineering
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• v.29 no.2
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• pp.132-139
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• 1996

Experiments on the automatic control of NaOH concentration and on the spraying condition of NaOH solution in the alkaline degreasing process of a continuous hot-dip galvanizing line have been carried out in order to improve degreasing performance of a galvanizing sheet steel using laboratory degreasing and galvanizing simulators. The concentration of NaOH for the good degreasing has been determined to be 6.0% and more and this concentration has been able to be automatically well controlled within $\pm$0.1% by employing a solution electrical conductivity meter under a flow injection analysis condition rather than by employing a sodium ion selective electrode in the degreasing simulator. Frequent blocking of the spraying nozzles of the solution has been reduced considerably by the set-up and periodical operation of an automatic valve system in the nozzle system. By applying this automatic valve system and by automatic controlling the NaOH concentration and other ordinary variables in the degreasing process, the degreasing performance has been increased from the conventional 76% to the new 85%.

• 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.

• 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.

• 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.

• Journal of Yeungnam Medical Science
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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.

• Journal of the Korean Chemical Society
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• v.41 no.12
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• pp.653-660
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• 1997

Silicone rubber-matrix membranes doped with tetradecyltrimethylammonium chloride (TDTMACl) are used to enhance electrode performance for chloride measurements in physiological samples. The optimized membrane formulation incorporates 95.4 wt% silicone rubber and 4.6 wt% TDTMACl, and its pH response is negligible in the range of pH 6-10. The TDTMACl-doped silicone rubber membrane exhibits sub-Nernstian response to chloride from 10 to 300 mM (-37.5 mV/decade), but its selectivities for chloride over other anions are remarkably enhanced: KpotCl,NO3=1.3, KpotCl,I=2.0, KpotCl,Sal=0.8, KpotCl,SCN=2.0 and KpotCl,ClO4=0.8. Furthermore, since the silicone rubber-matrix membrane exhibits better adhesion to the solid surface than do PVC membranes, the lifetime of the coated-wire type membrane electrode is greatly improved. The response properties toward chloride and salicylate for solid-state sensor are not significantly changed after at least 35 days of use.

• 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.

• 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.