| Budget Amount *help |
¥8,600,000 (Direct Cost: ¥8,600,000)
Fiscal Year 1997: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1996: ¥5,400,000 (Direct Cost: ¥5,400,000)
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| Research Abstract |
A water-soluble porphyrin (2,3.7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin ; H<@D22@>D2obtpps<@D14-@>D1 ; H2P<@D14-@>D1) was synthesized and develped for the determination and separation of lithium ion in aqueous solution. Tne octabromo groups lower the basicity of the porphyrin by their eletron-withdrawing effect and enable the porphyrin to react with lithium ion in alkaline aqueous solution to form the lithium complex along with a shft of absorption maxima ; lmax (log epsilon/mol<@D1-1@>D1 dm<@D13@>D1 cm<@D1-1@>D1) of thg lithium porphyrin are 490.5 nm (5.31) and 734 nm (4.36). Sodium and potassium ions did not react with the porphyrin. The equilibrium constant for the reaction Li<@D1+@>D1+HP<@D15-@>D1 [LiP]<@D15-@>D1+H<@D1+@>D1 was found to be 10-8.81 and the condtional formation constant ofthe [LiP]<@D15-@>D1 at pH l3 is10<@D14.21@>D1.The [LiP]<@D15-@>D1 can be extracted into chloroform as an ion-pair complex with tetracuthylammonium ion (X<@D1+@>D1) and the extracted X<@D25@>D2LiP dissociates to X<@D24@>D2LiP<@D1-@>D1 and X<@D1+@>D1 in chlomform. The exttraction constant for the reaction of [LiP<@D15@>D1-]<@D2a@>D2+5[X<@D1+@>D1]<@D20@>D2(]SY.dblharw.[)[X<@D24@>D2LiP<@D1-@>D1]<@D20@>D2+[X<@D1-@>D1]<@D20@>D2 was found to be (8.4(]SY.+-。[)0.7) x 10<@D112@>D1 mol<@D1-4@>D1 dm<@D112@>D1, where subscripts of a and o denote chemical species in aqueous and organic phases, respectively. The above results were developed for the determination of lithium in serum, sea water and hot-spring water samples at a range of 0.07-0.7 mg dm<@D1-3@>D1 (1 x 10<@D1-5@>D1-1 x 10<@D1-4@>D1 mol dm<@D1-3@>D1). The interference of hevy metal ions was by N,N'-1,2-ethanediylbis-[N (carboxylmethyl)-glycinato] magnesium (II) ([Mg (edta)]<@D12-@>D1 or H<@D24@>D2 edta if sample contain magnesium (II) ion.
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