• 약학회지
• /
• 제43권3호
• /
• pp.300-305
• /
• 1999

A sensitive and efficient assay method was applied to determine the level of glutamic acid (GA) and ${\gamma}-aminobutyric$ acid (GABA) in frontal cortex and hippocampus of rat administrated with ethanol and drugs. The compounds were derivatized with ο-phthalaldehyde (OPA) and 2-mercaptoethanof for precolunm analysis. The condition for the simultaneous determination of GA, GABA and $\beta-aminobutyric$ acid (BABA) by high performance liquid chromatography with electrochemical detection was reverse phase $C_{18}$ column as stationary phase, 0.1 M phosphate buffer containing 0.1 mM $Na_4EDTA$ : methanol = 55:45 (v+v) pH 3.8 as mobile phase and 0.7V electrode voltage. The stability of reaction product of GA, GABA and BABA with OPA could be increased by adding the same volume of polyethylene glycol 400 to reaction mixture. The GABA level in frotal cortex of rat was significantly decreased by the administration of picrotoxin and diazepam, but it was significantly increased by the administration of red ginseng total saponin, N-methyl-D-glucamine and (-)-deprenyl.

• Journal of Electrochemical Science and Technology
• /
• 제14권1호
• /
• pp.66-74
• /
• 2023

In this study, a new potentiometric sensor selective to copper(II) ions was developed and characterized. The developed sensor has a polymeric membrane and contains 4.0% electroactive material (ionophore), 33.0% poly(vinyl chloride) (PVC), 63.0% bis(2-ethylhexyl)sebacate (BEHS) and 1.0% potassium tetrakis(p-chlorophenyl)borate (KTpClPB). This novel copper(II)-selective sensor exhibits a Nernstian response over a wide concentration range from 1.0×10^-6 to 1.0×10^-1 mol L^-1 with a slope of 29.6 (±1.2) mV decade^-1, and a lower detection limit of 8.75×10-7 mol L^-1. The sensor, which was produced economically by synthesizing the ionophore in the laboratory, has a good selectivity and repeatability, fast response time and stable potentiometric behaviour. The potential response of the sensor remains unaffected of pH in the range of 5.0-10.0. Based on the analytical applications of the sensor, we showed that it can be used as an indicator electrode in the quantification of Cu²⁺ ions by potentiometric titration against EDTA, and can also be successfully utilized for the determination of copper(II) ions in different real samples.

• 대한화학회지
• /
• 제8권3호
• /
• pp.109-112
• /
• 1964

A volumetric method of the determination of calcium carbonate and calcium fluoride in fluorspar concentrate is described. The carbonate is converted into solution by treatment of the sample in HNO$_3$-acetone (l% by volume) mixture, and the fluoride by treating the residue with H$_3BO_3$-HCl mixture. The calcium in the solution is determined volumetrically using EDTA standard solution. The selective dissolution of calcium carbonate by HNO$_3$-acetone mixture is superior to Bidtel's acetic method and little correction for the dissolution of calcium fluoride is needed. Triethanolamine is found to be superior to KCN in masking heavy metal ions.

• 약학회지
• /
• 제4권1호
• /
• pp.43-46
• /
• 1959

A new quantitiative analytical method of prussic acid by "Microdiffusion analysis" was studied. HCN-Glucoside of ARMENIACA was hydrolysed with KOH in out-room of unit, and then concentrated sulfuric acid was poured in order to liberate the HCN gas. The liberated gas was absorbed into nickel sulfate solution of inner room of unit quantitatively. The excess of nickel sulfate was determined by EDTA Reagent using MX-indicator. By this method, the following results were obtained: (1) It was needed more than 4 hours, in order to hydrolyse completely at $50^{\circ}C$, but could be shortened to 3 hrs. at $^60{\circ}C$. (2) It was completely absorbed into nickel sulfate solution after 30min.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1996년도 추계학술대회
• /
• pp.251-253
• /
• 1996

Noninvasive monitoring of total Hemoglobin value is feasible with the use of spectroscopic measurements. As a step toward tile final goal of the development of a noninvasive monitor, the spectra$(400{\sim}800mm)$of EDTA whole blood were obtained along with reference total Hemoglobin values. Under the same condition water spectrum was generated. It was subtracted from each blood sample, and then tile first derivative of each subtracted data was taken by 'approximated first derivative algorithm' with gap (1,6,10,20nm). The correlation was obtained between total Hemoglobin and first valley wavelength of first derivative spectrum (sample number: 93).

• 분석과학
• /
• 제8권4호
• /
• pp.611-615
• /
• 1995

The design of appropriate chemically modified electrodes should allow development of new voltammetric measurement schemes with enhanced selectivity and sensitivity. Microorganism like algae has high ability to trap toxic and heavy metal ions and different affinities for metal ions. A copper(II) ion-selective carbon paste electrode was constructed by incorporating alga Anabaena into a conventional carbon paste mixture, and then the film of 10% Nafion was coated to avoid the swelling of the electrode surface. Copper ion could be deposited at the 25% algamodified electrode for 15 min without the applied potential while stirring the solution by only immersing the electrode in a buffer (pH 4.0) cot1taining copper(II). Temperature was controlled at $35^{\circ}C$. After preconcentration was carried out the electrode was transferred to a 0.1 M potassium chloride solution and was reduced at -0.6 volt at $25^{\circ}C$. The differential pulse anodic stripping voltammetry was employed. A well-defined oxidation peak could be obtained at -0.1 volt (vs SCE). In five deposition / measurement / regeneration cycles, the responses were reproducible and relative standard deviations were 3.3% for $8.0{\times}10^{-4}M$ copper(II). Calibration curve for copper was linear over the range from $2.0{\times}10^{-4}M$ to $1.0{\times}10^{-3}M$. The detection limit was $7.5{\times}10^{-5}M$. Studies of the effect of diverse ions showed that the coexisting metal ions had little or no effect for the determination of copper. But anions such as cyanide. oxalate and EDTA seriously interfered.

• 대한화학회지
• /
• 제53권2호
• /
• pp.144-151
• /
• 2009

카드뮴이온 검출을 위한 optode를 triacetylecelluose 막에 있어 dithizone을 고정에 의하여 디자인 되었다. Optode 막이 카드뮴을 포함하는 611 nm 에서 흡수 변화가 가능한 실제시료에 도입 되었을 때 녹색에서 붉은 색으로 색 변화가 일어났다. $Cd^{2+}$ 이온 검출은 검출한계가 0.025 ${\mu}g\;ml^{-1}$ (25 ng $ml^{-1}$)이고 0.3-3 ${\mu}g\;ml^{-1}$ (2.67-26.67 ${\mu}M$)범위에서 가능하였다. Optode의 반응 시간은 $Cd^{2+}$ 이온에 의존하여 15분 안 에서 일어 났다. 다른 간섭종의 효과에 대해 시험되었고 좋은 선택성을 보였다. 제안된 optode를 사용하 여 오염된 토양과 물시료에서 $Cd^{2+}$ 이온의 검출 결과는 잘 확립된 원자흡수법과 동등하게 얻을 수 있었다.

• Bulletin of the Korean Chemical Society
• /
• 제26권10호
• /
• pp.1529-1532
• /
• 2005

A simple and cost effective method for separation and preconcentration of Ag(I) at the $10^{-7}\;mol\;L^{-1}$ level in the environmental and mineral samples is present. The method is based on the flotation of Ag(I)-iodide complex as an ion-associate with ferroin in pH of 4 from a large volume of an aqueous solution (500 mL) using nheptane. The floated layer was then dissolved in dimethylsulfoxide (DMSO) for the subsequent spectrophotometric determination. Beer's law was obeyed over a range of 2.0 ${\times}$ $10^{-7}$-4.0 ${\times}$ $10^{-6}$ mol $L^{-1}$ with the apparent molar absorptivity of 2.67 ${\times}$ $10^5$ L $mol^{-1}\;cm^{-1}$. The detection limit (n = 5) was 4 ${\times}$ $10^{-8}$ mol $L^{-1}$, and RSD (n = 5) obtained for 2.0 ${\times}$ $10^{-6}$ mol $L^{-1}$ of Ag(I) was 2.2%. The interference effects of a number of elements was studied and found that only $Hg^{2+}$ at low concentration, and $Pb^{2+}$, $Cd^{2+}$, $Cu^{2+}$, and $Fe^{3+}$ ions at moderately high concentrations were interfered. To overcome on these interference effects, the solution was treated with EDTA at a buffering pH of 4 and passed through a column containing Amberlite IR-120 ionexchanger resin, just before the flotation process. The proposed method was applied to determine of Ag(I) in a synthetic waste water, a photographic washing sample and a geological sample and the results was compared with those obtained from the flame atomic absorption spectrometry. The results were satisfactorily comparable with together, so that the applicability of the proposed method was confirmed in encountering with the real samples.

• Applied Biological Chemistry
• /
• 제10권
• /
• pp.1-13
• /
• 1968

phytin은 phytic acid의 금속염(金屬鹽)(주(主)로 Ca 와 Mg)임으로 그중(中)의 P,Ca 및 Mg를 정량(定量)하면 순도(純度)를 알 수 있고, 또 분자식(分子式)을 추정(推定)할 수 있다. 저자(著者)는 phytin 중(中)의 P,Ca 및 Mg를 정량분석(定量分析)하는 새로운 방법(방법)으로 서 phytin을 건식(乾式) 분해(分解)하고 ion 교환수지(交換樹脂)로 처리한 다음 Chelate 법(法)으로 정량(定量)하는 방법(方法)을 확정(確定)켰으며 그 결과(結果)를 요약(要約)하면 다음과 같다. 1) phytin 분석(分析)의 전처리과정(前處理課程)으로서는 phytin을 conc. $HNO_3$로 적시면서 $550{\sim}660^{\circ}C$에서 회화(灰化)하는 건식분해법(乾式分解法)을 썼다. 이 방법(方法)은 습식분해법(濕式分解法)보다 분석결과(分析結果)가 정확(正確)하다. 2) phytin을 건식분해(乾式分解)한 시료(試料)를 가지고 종래법(從來法)과 새로운 분석법(分析法) (본법(本法))에 의하여 P,Ca 및 Mg를 정량(定量)하였으며, 본법(本法)은 다음고 같다. phytin 회분(灰分 HCl 용액(溶液)을 양(陽) ion 교환수지(交換樹脂)로 처리하여 양(陽) ion 구분(區分)과 음(陰) ion 분리(分離)하고 양(陽) ion 구분(區分)의 일부(一部)를 pH 7.0로 한다음 완충액(緩衝液)($NH_3-NH_4Cl$으로 pH 10으로 하고 BT 지시약(指示藥)을 써서 표준(標準) EDTA 용액(溶液적정(滴定)하여 Ca와 Mg의 합계치(合計値)를 얻었다. 또 양(陽) ion 구분(區分)의 일부(一部)를 pH 7.0로 하고 표준(標準) EDTA 용액(溶液)을 소량(少量)넣고 8N-KOH로 pH $12{\sim}13$으로 하고 N-N 희석분말(稀釋粉末)을 지시약(指示藥) 으로써 표준(標準) EDTA 용액(溶液)으로 적정(滴定)하여 Ca 치(値)를 얻었다. Ca와 Mg의 합계결정치(合計決定値)와 Ca 적정치(滴定値) 차(差)로 Mg 치(値)를 얻었다. 음(陰) ion 구분(區分)으로부터 상법(常法)에 의하여 $MgNH_4PO_4$의 침전(沈澱)을 만들어서 HCl에 녹키고 일정량(一定量)의 표준(標準) EDTA 용액(溶液)을 넣어 pH 7.0로 한다음 완충액(緩衝液)으로 pH 10으로 하고 BT 지시약(指示藥)을 써서 표준(標準) Mg $SO_4$용액(溶液)으로 적정(滴定)하여 P 치(値)를 얻었다. 본법(本法)으로 Na-phytate를 분석(分析)한 결과(結果) Na-phytate의 분자식(分子式)을 $C_6H_6O_{24}P_6Mg_4CaNa_2{\cdot}5H_2O$라고 하였을 때의 이론치(理論値)에 비(比)하여 P가 98.9% Cark 97.1%, Mg가 99.1%이고 통계처리(統計處理)한 결과분석치(結果分析値)와 이론치(理論値)는 잘 일치(一致)된다. 그러나 종래법(從來法)에 의(依)한 분석치(分析値)는 이론치(理論値)에 비(比)하여 P가 92.40%, Cark 86.80%, Mg가 93.80%로서 이론치(理論値)와 일치(一致)하지 않는다. 3) Na-phytate를 전분(澱粉)과 일정(一定)한 비(比)로 혼합(混合)하고 본법(本法)으로 P,Ca 및 Mc를 정량(定量)한 결과(結果) 이들의 회수율(回收率)은 거의 100%이었다. 4) 본분석법(本分析法)의 정확성(正確性)을 재확인(再確認)하기 위하여 phytic acid 수용액(水溶液)에 $CaCl_2$수용액(水溶液)을 phytic acid 1M:$CaCl_25M:McCl_220M$의 비(比)로 반응(反應)서키어서 Ca 1 원자(原子), Mg 4원자함유(原子含有)된 Na-phytate를 합성(合成)하였으며 이것의 P,Ca 및 Mg 분석치(分析値)와 의(依한) 조제(調製) Naphytate의 분석치(分析値)와 일치(一致)되었다. 이상(以上)과 같이 phytin 시료(試料)를 건식분해(乾式分解)하고 ion 교환수지(交換樹脂)로 처리(處理)한 다음 Chelate 법(法)으로 P,Ca 및 Mg를 정량(定量)하는 본법(本法)은 정확(正確)하고 신속(迅速)한 phytin의 새 분석방법(分析方法)이라고 사료(思料)되는 바이다.

• 대한화학회지
• /
• 제36권5호
• /
• pp.638-643
• /
• 1992

황화이온검출기로서 2가지 형태의 연속 flow-through 전극계의 분석적 감응성질을 조사하고, 최적조건에서 그들의 감응특성을 직접 비교하였다. 두 검출계에 있어서 측정한 봉우리전위를 황화이온농도의 대수값과 관련지웠으며, 적어도 시간당 20개의 시료를 정량할 수 있었다. pH전극법에서는 투석기를 지나 흘러가는 recipient stream의 pH를 측정하였다. 장치는 연속흐름형의 기체투석기가 관형 polymer 막전극과 연결되도록 설계되어 있다. 이 방법의 최적실험조건은 recipient $5.0 {\times} 10^{-5} M NaOH ＋ 5.0 {\times} 10^{-3} M$ NaCl과 diluent 0.10M $H_2SO_4$이며, recipient stream, diluent stream 및 시료의 유속은 모두 1.0ml/min이다. 황화이온 전극법에서는 시판하는 황화이온선택성 전극을 flow-through cell 속의 황화이온을 검출하는 데에 썼다. 이 방법의 최적실험조건인 황화이온 산화방지 완충제(1.0M NaOH 용액에 3.5g 아스코르브산과 7.6g $Na_2EDTA$를 용해)와 시료의 유속은 각각 1.4 ml/min와 1.0 ml/min이다.