• Bulletin of the Korean Chemical Society
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• 제26권4호
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• pp.579-584
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• 2005

The 3-[(2-furylmethylene)amino]-2-thioxo-1,3-thiazolidin-4-one (FTT) was used as an excellent ionophore in construction of a $Zn^{2+}$ PVC-based membrane sensor. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride), 62% nitrobenzen (NB), 3% FTT and 5% sodium tetraphenyl borate (TBP). This membrane sensor shows very good selectivity and sensitivity towards $Zn^{2+}$ over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The membrane sensor revealed a great enhancement in selectivity coefficients for $Zn^{2+}$ ions, in comparison to the previously reported $Zn^{2+}$ membrane sensors. Theoretical studies also showed the selective interaction of TFF and $Zn^{2+}$ ions. The proposed membrane sensor exhibits a Nernstian behavior (with slope of 29.3 ${\pm}$ 0.3 mV per decade) over a wide concentration range (1.0 ${\times}$ $10^{-6}$-1.0 ${\times}$ $10^{-2}$) with a detection limit of 8.5 ${\times}$ $10^{-7}$ M (52 ng mL$^{-1}$). It shows relatively fast response time, in the whole concentration range ($\lt$ 20 s), and can be used for at least 10 weeks in a pH range of 3.0-7.0. The proposed membrane sensor was successfully used in direct determination of $Zn^{2+}$ ions in wastewater of industrial zinc electroplating companies, and also as an indicator electrode in titration with EDTA.

• Bulletin of the Korean Chemical Society
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• 제26권1호
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• pp.38-42
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• 2005

Bis(2-methylbenzaldehyde)butane-2,3-dihydrazone(TDSB) was used as new N-N Schiff's base which plays the role of an excellent ion carrier in the construction of a La(III) membrane sensor. The best performance was obtained with a membrane containing, 30% poly(vinyl chloride), 60% benzyl acetate, 6% TDSB and 4% sodium tetraphenyl borate. This sensor reveals a very good selectivity towards La(III) ions over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The proposed electrode exhibits a Nernstian behavior (with slope of 19.8 mV per decade) over a wide concentration range (1.0 ${\times}$ 10$^{-5}$-1.0 ${\times}$ 10$^{-1}$ M). The detection limit of the sensor is 7.0 ${\times}$ 10$^{-6}$ M. It has a very short response time, in the whole concentration range ($\sim$5 s), and can be used for at least twelve weeks in the pH range of 3.0-9.4. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a La(III) solution, with EDTA. It was also successfully applied in the determination of fluoride ions in three mouth wash preparations.

• 전기화학회지
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• 제11권1호
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• pp.59-63
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• 2008

Poly (vinylchloride) (PVC) membrane electrodes based on neutral carrier, tetracycline was prepared as an active sensor for Hg(II) ion, and tested in different contents of the potassium tetrakis (4-chlorophenyl) borate (KTpClPB) as lipophilic salt. Bis (2-ethylhexyl) sebacate (DOS), bis(l-butylpentyl) adipate (BBPA), 2-nitrophenyl octyl ether (NPOE) and dibutyl phthalate (DBP) were used as diverse plasticizing solvent mediators. This electrode shows excellent potentiometric response characteristics and display good linearity with log $[Hg^{+2}]$ versus EMF response, over a range of concentrations between $10^{-7}$ and $10^{-3}M$. With 30.8mV/decade Nernstian slope, the detection limit was $6.9{\times}10^{-9}M$ and the response time was less than 20s. The proposed electrode yields very good selectivity for mercury (II) ion over many cations such as alkali, alkaline earth, transition and heavy metal ions. And it shows a very stable potential values in a wide pH range. This reliable electrode prepared was kept at least a month without considerable alteration in their response to Hg (II) ion.

• Bulletin of the Korean Chemical Society
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• 제23권10호
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• pp.1394-1398
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• 2002

A novel copper(II) membrane electrode based on diphenylisocyanate bis(acetylacetone) ethylenediimine (DIBAE), as a new hexadentates Schiff's base was prepared. The electrode exhibited a Nernstian response for Cu$^{2+}$ ions over a wide concentration range (1.0 ${\times}$ 10$^{-1}$ to 1.0 ${\times}$ l0$^{-6}$ M) with a limit of detection of 6.0 ${\times}$ 10$^{-7}$ M (39 ppb). The sensor shows a fast response time (15s) and the membrane can be used for more than 4 months without observing any major deviation. The electrode revealed very good selectivity with respect to many cations including alkali, alkaline earth, transition and heavy metal ions. The proposed sensor could be used in a pH range of 3.0-7.5. It was applied to the direct potentiometric determination of copper in black tea, and in wastewater of copper electroplating samples. The electrode was also used in potentiometric titration of the copper(II) ion with EDTA.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3592-3596
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• 2011

A novel poly(vinylchloride)-based membrane sensor using $N^1$,$N^3$,$N^5$-tris(2-(2,3-dihydroxybenzylamino)-ethyl)cyclohexane-1,3,5-tricarboxamide (CYCOENCAT, L) as ionophore has been prepared and explored as $Fe^{3+}$ selective electrode. The membrane electrode composed of ionophore, poly(vinylchloride) and o-nitropheyloctyl ether in the optimum ratio 4:33:63 gave excellent potentiometric response characteristics, and displayed a linear log[$Fe^{3+}$] versus EMF response over a wide concentration range of $1.0{\times}10^{-5}-1.0{\times}10^{-1}$ M with super nernstian slope of 28.0 mV/decade and the detection limit of $8.0{\times}10^{-6}$ M. The proposed ion selective electrode showed fast response time (< 15 s), wide pH range (3.0-7.0), high non-aqueous tolerance (up to 20%) and adequate long life time (120 days). It also exhibited very good selectivity for $Fe^{3+}$ relative to a wide variety of alkali, alkaline earth, transition and heavy metal ions. Further, the analytical applicability of the sensor was tested as an indicator electrode in the potentiometric titration of $Fe^{3+}$ with EDTA.

• Bulletin of the Korean Chemical Society
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• 제28권1호
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• pp.68-72
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• 2007

A new PVC membrane potentiometric sensor that is highly selective to Hg2+ ions was prepared, using bis(2-hydroxybenzophenone) butane-2,3-dihydrazone (HBBD) as an excellent hexadendates neutral carrier. The sensor works satisfactorily in the concentration range of 1.0 × 10-6 to 1.0 × 10-1 mol L-1 (detection limit 4 × 10-7 mol L-1) with a Nernstian slope of 29.7 mV per decade. This electrode showed a fast response time (~8 s) and was used for at least 12 weeks without any divergence. The sensor exhibits good Hg2+ selectivity for a broad range of common alkali, alkaline earth, transition and heavy metal ions (lithium, sodium, potassium, magnesium, calcium, copper, nickel, cobalt, zinc, cadmium, lead and lanthanum). The electrode response is pH independent in the range of 1.5-4.0. Furthermore, the developed sensor was successfully used as an indicator electrode in the potentiometric titration of mercury ions with potassium iodide and the direct determination of mercury in some binary and ternary mixtures.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1585-1589
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• 2003

A PVC-based membrane electrode for thallium(I) ions based on 1,21,23,25-tetramethyl-2,20: 3,19-dimetheno-[H, 2] H, 23H, 25H-bis-[1,3] dioxocino[5,4-i:5',4'-i] benzo [1,2-d: 5.4-d'] bis [1,3] benzodioxocin(II) has been prepared. The electrode displays a linear dynamic range of $1.0{\times}10^{-1}-1.0{\times}10^{-5}$ M, with a Nernstian slope of $59.8{\pm}0.2\;mV\;{decad^-1}$, and a detection limit $5.0{\times}10^{-6}$ M. It has a very fast response time of<10 s and can be used for at least ten weeks without a considerable divergence in potentials. This electrode revealed comparatively good selectivity with respect to alkali, alkaline earth, and some transition and heavy metal ions and was effective in a pH range of 2.0-10.0. It was used as an indicator electrode in potentiometric titration of thallium ion with sulfide ion.

• 생명과학회지
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• 제16권6호
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• pp.877-883
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• 2006

발효산업에 많이 사용되는 A. pullulans를 사용하여 독성 중금속인 납에 대한 제거량을 살펴보았다. 용액 중의 중금속을 제거할 때 A. pullulans가 다른 중금속에 비해 납에 대한 선택성이 우수하였으며 $40^{\circ}C$에서 최대 흡착량을 나타내었으며 또한 최적 pH가 9일 경우에 흡착량이 증가하였다. 초기납의 농도가 96 mg/l 인 경우에 단위 미생물당 흡착량이 120mg/g로 짧은 시간내에 많은 양의 납을 제거함을 알 수 있었다. 그리고 약 200 mg Pb/g cell dry weight 정도가 최대 납 흡착량인 것으로 나타났다. 그리고 미생물의 보존기간에 따라 세포외 고분자물질의 분비가 증가하여 납 흡착량을 증가시켰으며, Freundlich 모델에 잘 적용되었다. 그리고 살아있는 상태가 사멸된 상태에서 평형흡착량은 약 2배 정도 흡착능이 우수함을 알 수 있었으며, 그에 따라서 초기 흡착속도도 살아있는 상태가 사멸된 상태보다 훨씬 빠른 것을 알 수 있었다.

• 한국토양비료학회지
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• 제41권6호
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• pp.369-373
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• 2008

Mg-Al LDH를 이용하여 수용액중 비소와의 반응특성을 규명하고 비소 제거제로서 활용가능성을 규명하기 위하여 비소의 흡착특성, 제거효율 및 제거기작에 대한 조사를 하였다. Mg-Al LDH는 소성(calcination)에 의한 탈수로 Mg oxide 형태를 나타내었고 비소를 흡착시킨 결과 반응 22시간 이후에 흡착평형에 도달하였으며 흡착량은 약 530 mmol/kg정도였다. 반응농도별 LDH의 등온흡착은 L-type의 흡착반응을 나타내었다. 소성된 Mg-Al LDH는 용액중에서 재수화(rehydration) 될 때 비소가 LDH의 구조의 복구과정(reconstruction)에서 이온교환 반응에 의해 층간삽입이 일어나는 것으로 나타났다. LDH에 대한 arsenate와 phosphate, arsenate와 sulfate의 경쟁흡착 결과 arsenate와 phosphate의 선택성은 비슷한 편이었고, arsenate는 sulfate에 비해 선택성이 우수하였다. 따라서 calcined Mg-Al LDH는 비교적 높은 비소 제거효율을 나타내므로 비소 제거제로서 사용 가능성이 매우 높은 것으로 판단된다.

• 자원리싸이클링
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• 제10권2호
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• pp.13-19
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• 2001

7.5%의 methyl acrylate가 함유된 압출 PAN(polyacrylonitrile)을 NaOH와 함께 메탄올상에서 다양한 온도와 시간으로 반응을 시켜 친수성이 부여된 압출 PAN을 제조하였다. 이 PAN들을 hydroxylamine과 함께 메탄올과 수용액 상에서 반응시켜 금속이온에 대해 최적의 흡착특성을 가지는 아미독심기를 부여하였다. 친수성이 부여된 아미독심화 압출 PA처은 친수성이 부여되지 않은 압출 PAN에 비하여 우수한 팽윤성를 보였다. 친수성이 부여된 아미독심화 압출 PAN은 $60^{\circ}C$, 6시간 동안 아미독심화 시켰을 때 가장 안정한 형태를 유지하였다. 친수성이 부여된 아미독심화 압출 PAN은 $Ni^{2+}$ 보다는 $Cu^{2+}$ 에 대해 높은 흡착능을 보였으며 또한 금속이온들에 대해 높은 선택성을 나타내었다.