• Journal of Pharmaceutical Investigation
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• 제32권1호
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• pp.1-6
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• 2002

The mucoadhesive characteristics of [P(AA-co-PEGMM)] films by estimating the glass transition temperature $(T_g)$, analyzing surface energy and studying FT-IR was previously reported. In this study, the possibility of buccal mucoadhesive dosage form of [P(AA-co-PEGMM)] films by mucoadhesive force measurements and dissolution tests were also investigated. Mucoadhesiveness of [P(AA-co-PEGMM)] films was compared with cr-PAA and cr-PEGMM films crosslinked with 3% ethyleneglycol dimethacrylate (EGDMA). The buccal mucoadhesive force of [P(AA-co-PEGMM)] films increased with increasing content of PEGMM. [P{AA-co-PEGMM (18 mole%)}] films showed a significantly greater mucoadhesiveness than cr-PAA and cr-PEGMM films. The mucoadhesive force measured in normal saline (pH 5.0) was higher than that measured in phosphate buffer (pH 6.8) because of the pH dependence of hydrogels with carboxyl ions within the PAA. Moreover, the mucoadhesive force of [P{AA-co-PEGMM (18 mole%)}] films was at maximum after 2 hr attachment of buccal mocosa and it was maintained over $1\;N/cm^2$ for up to 10 hr. In dissolution studies, the release of butorphanol tartrate from [P(AA-co-PEGMM)] films increased with increasing PEGMM content, and films prepared with 18 mole% PEGMM gave almost zero order release kinetics.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2748-2752
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• 2012

Cr(III) and Co(III) complexes with acetylacetonate were anchored onto a mesoporous MCM-41 through Schiff condensation. The materials were characterized by XRD, FT-IR, BET, CHN and ICP techniques. Elemental analysis of samples revealed that one C=N bond was formed through Schiff condensation on MCM-41 surface. The catalysts were tested for the alcohol oxidations using t-butyl hydroperoxide (TBHP) and $H_2O_2$ as oxidant. The catalytic experiments were carried out at both room temperature and reflux condition. Various solvents such as dichloromethane, acetonitrile and water were examined in the oxidation of alcohols. Among the different solvents, catalytic activity is found more in acetonitrile. Further, the catalysts were recycled three times in the oxidation of alcohols and no major change in the conversion and selectivity is observed, which shows that the immobilized metal-acetylacetonate complexes are stable under the present reaction conditions.

• 대한가정학회지
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• 제18권1호
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• pp.41-46
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• 1980

In order to verify to what extent the rancidity of the soybean oil is occurred and how the various metal ions effect on the rancidity-as a result of applying heat to the soybean oil-the followings are obtained through experiments : 1. From analyzing the refractive index of soybean oil, The results are: the specific gravity-0.925 refractive index-1.475, saponification value-190, acetyl value-5.0, iodine value-120, peroxide value-5.0. 2. The degree of expediting rancidity take the following order : $Cu^{++}$/$Fe^{++}$/$Cr^{++}$/$Zn^{++}$/$Ni^{++}$/$Al^{+++}$. 3. The degree of expediting rancidity of $Cu^{++}$and $Fe^{++}$ is showed the abrubt increase of peroxide value in accordance with the increase of densidity. The most abrubt increase of peroxide show when the duration of heating reaches to the range between 20 minutes and 30 minutes. After heating for 60 minutes no definite variation is showed. 4. The degree of rancidity in heating the soybean oil added $Cu^{++}$, Fe and BHA shows the decrease of peroxide value by 2, 3 after adding $Cu^{++}$0.5 ppm. and heating for 30 minutes. As the result of measuring the value of peroxide after adding $Cu^{++}$ by 1.0 ppm and BHA by 0.01% and heating, peroxide shows the decrease by 7.8 when adding anti-oxidant. $Fe^{++}$ as well as $Cu^{++}$ shows that BHA prevents the metal ions from the expedition of rancidity.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.444-450
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• 2011

A novel method that utilizes poly(5-methyl-2-thiozyl methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinylbenzene) [MTMAAm/AMPS/DVB] as a solid-phase extractant was developed for simultaneous preconcentration of trace Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), and Zn(II) prior to the measurement by flame atomic absorpiton spectrometry (FAAS). Experimental conditions for effective adsorption of the metal ions were optimized using column procedures. The optimum pH value for the simultaneously separation of the metal ions on the new adsorbent was 2.5. Effects of concentration and volume of elution solution, sample flow rate, sample volume and interfering ions on the recovery of the analytes were investigated. A high preconcentration factor, 100, and low relative standard deviation values, $\leq$1.5% (n = 10), were obtained. The detection limits (${\mu}gL^{-1}$) based on the 3s criterion were 0.18 for Cd(II), 0.11 for Co(II), 0.07 for Cr(III), 0.12 for Cu(II), 0.18 for Fe(III), 0.67 for Mn(II), 0.13 for Ni(II), 0.06 for Pb(II), and 0.09 for Zn(II). The validation of the procedure was performed by the analysis of two certified reference materials. The presented method was applied to the determination of the analytes in various environmental samples with satisfactory results.

• 대한환경공학회지
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• 제32권5호
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• pp.417-426
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• 2010

본 연구에서는 가죽 생산 공정 중 원피 무게의 50% 이상 고형 폐기물로 발생하는 콜라겐 단백질의 섬유 기재에 미모사(Catechol Tannin) 및 채스트넛(Pyrogallol Tannin)과 같은 식물성 탄닌물질을 다양한 조건에서 고정화시킨 10 가지 다른 종류의 바이오 흡착제를 제조하였다. 제조한 각 바이오 흡착제들의 중금속 제거용 흡착제로서의 성능 평가를 위하여 Cu(II), Cd(II), Zn(II), Pb(II), Cr(III) 이온을 함유한 인공 오염수를 사용하여 다양한 반응 조건에서의 회분식 실험을 실시하였으며, 중금속들의 제거 특성을 규명하였다. 미모사를 탄닌물질로 사용하여 콜라겐에 고정화 반응을 시켰을 때 섬유 번들 내부로의 미모사의 침투력은 나프탈렌계 침투제의 주입량에 비례 하였다; 3% ${\geq}$ 1.5% > 0%. 모든 바이오 흡착제들에서 pH 3.0 이하에서는 중금속 이온들의 제거는 거의 일어나지 않았으나 pH 3.0 이상에서 중금속의 제거율이 급격히 발생하였으며 Zn(II)을 제외한 나머지 중금속이온들은 pH 6.0 이상에서는 거의 완전히 제거되었다. Cr(III)의 경우에는 바이오 흡착제 종류별 제거량이 매우 유사한 경향을 나타내었으나 Cu(II), Zn(II), Pb(II)의 제거에서는 축합형 탄닌(미모사)에 비해 이온결합이 가능한 다량의 카르복실기를 함유한 가수분해형 탄닌(채스트넛)을 사용하여 고정화시킨 바이오 흡착제에서 높은 제거능을 보였다. S10 바이오 흡착제에 대한 Pb(II) 및 Cu(II) 중금속 이온들의 흡착은 이온농도가 1,000배 변화거나 경쟁이온 화학종을 일하전 및 이하전 화학종을 사용하였을 때 영향을 받지 않았다.

• 한국광물학회지
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• 제11권1호
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• pp.20-31
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• 1998

Adsorption of metal elements onto illite and halloysite was investigated at $25^{\circ}C$ using pollutant water collected from the gold-bearing metal mine. Incipient solution of pH 3.19 was reacted with clay minerals as a function of time: 10 minute, 30 minute, 1 hour, 12 hour, 24 hour, 1 day, 2 day, 1 week, and 2 week. Twenty-seven cations and six anions from solutions were analyzed by AAs (atomic absorption spectrometer), ICP(induced-coupled plasma), and IC (ion chromatography). Speciation and saturation index of solutions were calculated by WATEQ4F and MINTEQA2 codes, indicating that most of metal ions exist as free ions and that there is little difference in chemical species and relative abundances between initial solution and reacted solutions. The adsorption results showed that the adsorption extent of elements varies depending on mineral types and reaction time. As for illite, adsorption after 1 hour-reaction occurs in the order of As>Pb>Ge>Li>Co, Pb, Cr, Ba>Cs for trace elements and Fe>K>Na>Mn>Al>Ca>Si for major elements, respectively. As for halloysite, adsorption after 1 hour-reaction occurs in the order of Cu>Pb>Li>Ge>Cr>Zn>As>Ba>Ti>Cd>Co for trace elements and Fe>K>Mn>Ca>Al>Na>Si for major elements, respectively. After 2 week-reaction, the adsorption occurs in the order of Cu>As>Zn>Li>Ge>Co>Ti>Ba>Ni>Pb>Cr>Cd>Se for trace elements and Fe>K>Mn>Al, Mg>Ca>Na, Si for major elements, respectively. No significant adsorption as well as selectivity was found for anions. Although halloysite has a 1:1 layer structure, its capacity of adsorption is greater than that of illite with 2:1 structure, probably due to its peculiar mineralogical characteristics. According to FTIR (Fourier transform infrared spectroscopy) results, there was no shift in the OH-stretching bond for illite, but the ν1 bond at 3695 cm-1 for halloysite was found to be stronger. In the viewpoint of adsorption, illite is characterized by an inner-sphere complex, whereas halloysite by an outer-sphere complex, respectively. Initial ion activity and dissociation constant of metal elements are regarded as the main factors that control the adsorption behaviors in a natural system containing multicomponents at the acidic condition.

• 대한화학회지
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• 제23권4호
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• pp.198-205
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• 1979

금속이온의 $d^2sp^3$ 혼성궤도함수와 리간드의 singIe basis set 궤도함수를 사용하여 팔면체 [M(II)O_3S_3]$형태 착물의 쌍극자모멘트를 계산하는 원자가결합법을 발전시켰다. [M(III)=V(III), Cr(III), Mn(III), Fe(III), Co(III), Ru(III), Rh(III) 및 Os(III)]. 이 새로운 방법에 있어서 금속이온의 valence basis sets와 리간드 궤도함수사이의 혼성계수가 같다고 가정할 필요가 없으며 이것이 근사분자궤도함수법에 의한 팔면체 전이원소 착물의 쌍극자모멘트를 계산하는 방법과 다른점이다. 원자가결합법에서는 근사분자궤도함수법에서 보다도 훨씬 쉽게 팔면체착물의 쌍극자 모멘트를 계산할 수 있으며 계산한 쌍극자 모멘트의 값이 또한 실험치 범위에든다.

• The Journal of Advanced Prosthodontics
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• 제7권2호
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• pp.172-177
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• 2015

PURPOSE. The purpose of this study was to evaluate cell toxicity due to ion release caused by galvanic corrosion as a result of contact between base metal and titanium. MATERIALS AND METHODS. It was hypothesized that Nickel (Ni)-Chromium (Cr) alloys with different compositions possess different corrosion resistances when contacted with titanium abutment, and therefore in this study, specimens ($10{\times}10{\times}1.5mm$) were fabricated using commercial pure titanium and 3 different types of Ni-Cr alloys (T3, Tilite, Bella bond plus) commonly used for metal ceramic restorations. The specimens were divided into 6 groups according to the composition of Ni-Cr alloy and contact with titanium. The experimental groups were in direct contact with titanium and the control groups were not. After the samples were immersed in the culture medium - Dulbecco's modified Eagle's medium[DMEM] for 48 hours, the released metal ions were detected using inductively coupled plasma mass spectrometer (ICP-MS) and analyzed by the Kruskal-Wallis and Mann-Whitney test (P<.05). Mouse L-929 fibroblast cells were used for cell toxicity evaluation. The cell toxicity of specimens was measured by the 3-{4,5-dimethylthiazol-2yl}-2,5-diphenyltetrazolium bromide (MTT) test. Results of MTT assay were statistically analyzed by the two-way ANOVA test (P<.05). Post-hoc multiple comparisons were conducted using Tukey's tests. RESULTS. The amount of metal ions released by galvanic corrosion due to contact between the base metal alloy and titanium was increased in all of the specimens. In the cytotoxicity test, the two-way ANOVA showed a significant effect of the alloy type and galvanic corrosion for cytotoxicity (P<.001). The relative cell growth rate (RGR) was decreased further on the groups in contact with titanium (P<.05). CONCLUSION. The release of metal ions was increased by galvanic corrosion due to contact between base metal and titanium, and it can cause adverse effects on the tissue around the implant by inducing cytotoxicity.

• 대한화학회지
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• 제44권3호
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• pp.212-219
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• 2000

산성조건에서 HCr$O_4^-$이온과 $H_2O_2$사이의 산화-환원반응의 생성물인 $CrO(O_2)_2$의흡광도의 측정에 근거를 두어 개발된 흡수분광분석법에 FIA기법을 접목하여 $Cr_2O_7^{2-}$이온과 Mn$O_4^-$이온을 함유하는 혼합시료에 대한 새로운 분석법을 개발하였다. 새로운 분석법은 혼합물 시료의 분석과정에서 두 번에 걸친 주입분석을 수행해야 하고 $Cr_2O_7^{2-}$이온의 분석에 앞서 Mn$O_4^-$이온의 제거를 위한 별도의 작업을 선행해야 한다는 번거로움을 내포하지만, 두 가지의 분석파장들을 사용해야 하는 기존의 흡수분광분석법에 비해 단일분석파장(570 nm)를 사용할 수 있다는 장점을 가진다. 또한, 새로운 분석법은 주어진 분석파장(570 nm)에서 넓은 농도범위($Cr_2O_7^{2-}$이온:$2.0{\times}10^{-6}$M∼$8.0 {\times}10^{-3}$M,Mn$O_4^-$이온:$2.0{\times}10^{-6}$M∼$4.0{\times}10^{-3}$M)에 걸쳐 Beer의 법칙을 정확히 따르는 검정선의 작성이 가능하다는 점에 있어서 기존의 흡수분광분석법에 비해 $Cr_2O_7^{2-}$이온과 Mn$O_4^-$이온의 분석의 용이성을 더욱 증대시킬 수 있다는 장점도 가진다.

• 한국광물학회지
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• 제16권3호
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• pp.201-213
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• 2003

각종 산업폐수에서 심각한 환경문제를 야기시킬 수 있는 중금속(Ag, Pb, Cr, Cu, Zn, Mn) 이온들에 대한 국내산 주요 제올라이트의 흡착 성향 및 능력을 광물 조성 및 특성 분석과 일련의 흡착실험을 통해서 광석 단위로 평가해 보았다. 국내산 제올라이트 광석의 중금속 흡착 반응은 기본적으로는 양이온 교환방식에 의존되지만, 높은 CEC 값이 반드시 보다 많은 중금속 흡착능력을 의미하는 것은 아닌 것으로 나타난다. 제올라이트 광석의 중금속 흡착성향은 광종별로 다소 차이를 보이지만, 일반적으로 흡착선호도에 있어서 $Ag\geq$Pb>Cr, $Cu\geq$Zn>Mn와 같은 흡착 서열을 이루는 것으로 밝혀졌다. 휼란다이트는 Cr을 보다 더 선호하는 성향을 보이는 반면에, 클리놉틸로라이트는 Cu를 더 선호하는 경향을 나타낸다. 일반적으로 제올라이트의 광종에 관계없이 Ag와 Pb는 상대적으로 월등한 흡착선호도를 나타낸다. 특히 Ag는 Na에 의한 재용출 과정에서 전혀 유리되지 않을 정도로 제올라이트에 대한 높은 흡착성향을 보인다. 제올라이트 광석의 중금속 흡착능력은 광종별로 현격한 차이를 보인다: 페리어라이트>클리놉틸로라이트>휼란다이트. 이에 비해서 모오데나이트는 CEC 성향으로 보아 클리놉틸로라이트와 비슷한 수준인 것으로 해석된다. 제올라이트의 암모늄 이온에 대한 CEC 값과 중금속 이온 흡착능력은 엄밀히 잘 부합되지 않는 것으로 나타난다. 또한 제올라이트 광석들의 중금속 흡착능력은 대개 제올라이트의 함량, 즉 광석의 품위에 의존되는 경향을 보이지만, 광석에 따라 그 일반적 추이에서 크게 벗어난 흡착 양상을 보이기도 한다. 이는 제올라이트의 선택적 흡착특성, 중합단층의 존재와 같은 구조적 결함이나 천연상 교환성 양이온의 조성(특히 흡착선호도가 높은 K의 함유도)에 의한 효과로 추정된다. 국내산 제올라이트를 중금속 흡착제거용으로 응용하는 데에는 부존자원의 활용성, 경제성 및 성능을 고려하여 클리놉틸로라이트 계열의 광석을 사용하는 것이 합리적일 것으로 판단된다.