著者

鈴木 孝範 森永 博

出版者

公益社団法人日本分析化学会

雑誌

分析化学 (ISSN:05251931)

巻号頁・発行日

vol.25, no.10, pp.712-714, 1976-10-10

被引用文献数

1

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A simple and sensitive method was investigated for determination of zinc in copper alloy. The method is based on the combination of anion exchange separation by batch operation and EDTA titration. Sample is dissolved in 15 ml of HN0_3(1+1) by heating, and resultant diluted to 200 ml with water. A 20 ml aliquot of this solution and 2 ml of H_2SO_4 (1+1) are taken into a beaker, and are evaporated to dryness. After cooling, the residue is dissolved in 2 N HCl by heating. The solution is transfered into the separatory funnel with a filter containing anion exchange resin Amberlite IRA-400, RCl form, (60〜80) mesh. The separatory funnel is shaken for 4 minutes to adsorb zinc ion. The solution in the funnel is sucked off. Resin is washed by shaking for 20 seconds with 25 ml of 2 N HCI (containing 0.01% Pb) and this operation is repeated (5〜7) times. The adsorbed zinc ion is eluted with 20 ml of 2 N NH_40H (containing 40 g/I NH_4Cl) by shaking for 2 minutes, and the eluent is filtered into an Erlenmeyer flask with suction, and this operation is repeated 5 times. The eluted solution is diluted to 200 ml with water, and mixed with 2 ml of potassium cyanide solution (10%) and 3 ml of formaldehyde solution (2+8) to mask the other metal ions. The solution is titrated with 0.02 M EDTA solution by using EBT as indicator. The time required for this test was about half of a usual column method.

著者

鈴木 孝昌

出版者

日本環境変異原学会

雑誌

環境変異原研究 (ISSN:09100865)

巻号頁・発行日

vol.25, no.2, pp.119-125, 2003 (Released:2005-08-19)

参考文献数

15

被引用文献数

1 1

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The transgenic mouse mutation assay was developed as a striking new tool for mutation research in 1990. This assay enables the detection of mutations in a transgene in multiple organs including germinal tissues and thus reveals organ-specific genotoxicity of the mutagen. Following its introduction in MutaMouse and Big Blue mouse systems, modification of the methodology, mainly the introduction of the positive selection system and development of other transgenic animal models including rat, improved and assured the relevance of the assay. Accumulation of experimental data suggests the transgenic mouse mutation assay can be used as a standard in vivo test for mutagenesis.We have developed a multi-endpoint test, by combining the peripheral blood micronucleus assay with the transgenic mouse mutation assay. This test allows simultaneous detection of clastogenecity and mutagenecity in vivo. Since these two endpoints indicate different characteristics of the mutagen, data from many chemicals suggest the importance of detecting both endpoints. With this approach, the transgenic assay could detect the mutagenecity of diethylnitrosamine, which failed to be detected in micronucleus assay.Another important advantage of this assay is its suitability for sequence analysis. Sequencing of the transgene enables to draw mutagen-specific mutation spectrum, a molecular signature of the mutagen, and is very useful to deduce the mechanism of mutagenesis. In this regard, we have intensively used a positively selectable target gene ‘cII’. This gene is relatively short (300 bp) which made the sequencing process easier and less time consuming and enables us to generate data on mutagenesis of several mutagens. We hope the database will be useful for molecular epidemiology in future.A quantitative comparison of carcinogenic and mutagenic potency of chemicals revealed a good correlation with transgenic mutation assay and therefore suggesting a usefulness of this assay for the quantitative risk assessment.