| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Research Abstract |
Environmental waters, such as river water, and tap water are contained about 10 ppb (10^<-8> g/g) of boron. These concentration level can be determined by our reported method. However, in the field of semi-conductor it is required at 10 ppt (10^<-12> g/g) level. In this investigation, I could improved previous method to determine these very low concentration level. Boron as boric acid was determined as a complex with chromotropic acid at pH 6.0 in an aqueous medium by fluorescence detection/ flow injection analysis. The complex was detected by measuring fluorescence intensities( λ_<ex>=313 nm, λ_<em>=360 nm). EDTA was used for buffer component with a role of masking agent to metal ions. Background fluorescence of chromo-tropic acid was decreased by mixing with 0.1 M ammonia water after the complex formation, resulting in stable baseline. The calibration graph was rectilinear from 10^<-9> 〜 10^<-6> mol dm^<-3> and the detection limit was 5x10^<-10> M (S/N=3). The reproducibility was 3.61% (n=10, with peak height) at 6x10^<-9> M of boron and sample throughput was 40 h^<-1>. Application to river water, ion exchanged water and distilled water could be done without any pretreatments. For analysis of ultrapurified water, evaporation / preconcentration procedure was carried out, because the concentration was under the LOD and no reference water which could be used for carrier solution or preparation of the reagent solutions.
Next, I synthesized few novel fluorescence reagents with naphthalenedisulfonic acid introduced di-(toluene-4-sulfonyl-amino) group or di-(trifluoromethanesulfonylamino) group. These reagents could react with boron.
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