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ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 25, Number 1
BKCSDE 25(1)
January 20, 2004 |
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Title |
Tetrahydrofuran-Containing Crown Ethers as Ionophores for NH+4-Selective Electrodes
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Author |
Hua Yan Jin, Tae Ho Kim, Jineun Kim, Shim Sung Lee, Jae Sang Kim*
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Keywords |
Ammonium ionophore, Ion-selective PVC membrane electrodes, THF-containing crown ethers, Nonactin
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Abstract |
The ammonium ion-selective electrodes (NH+4-ISEs) based on the tetrahydrofuran(THF)-containing-16-crown-4 derivatives,1,4,6,9,11,14,16,19-tetraoxocycloeicosane (L1) and 5,10,15,20,-tetramethyl-1,4,6,9,11,14,16,19-tetraoxocycloeicosane (L2), were prepared and the electrode characteristics were tested. The conditioned NH4+4ISEs (E1) based on L1 with TEHP as a plasticising solvent mediator gave best results with near-Nernstian slope of 53.9 mV/decade of activity, detection limit of 10-4.9 M, and enhanced selectivity coefficients for the NH+4 ion with respect to an interfering K+ ion (log Kpot NH4+,K+ = -1.84). This result was compared to other ammonium ionophores reported previously, for example, that of nonactin (log Kpot NH4+,K+ = -0.92). The proposed electrode showed no significant potential changes in the range of 3.0 < pH < 9.0.
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59 - 62 |
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