Univalent copper chelates of 4, 4′-disubstituted 2, 2′-biquinolines (I to X) were extracted with isoamyl alcohol and their spectrophotometric constants were measured. The ultraviolet absorption maxima of these compounds were as follows: mμ(ε): (II: -CONHEt) 565 (3, 100), (III: -CONH-iso-Pr) 566 (7, 100), (VI: -CONMe
2) 560 (6, 130), (VII: -CONEt
2) 561 (6, 260), (VIII: -CON (iso-Pr)
2) 556 (2, 810), (IX: -CONBu
2) 561 (5, 150), and (X: -CONMePh) 567 (7, 370). (I), (IV), and (V) were sparingly soluble and spectral measurement could not be made. Of these compounds, (X) showed absorption maximum in the longest wave-length region with the highest absorbance.
Examinations were made on the determination of copper, using sodium hydroxide solution of 2, 2′-bicinchoninic acid. The ratio of the acid to copper was 2:1 and the solution colored violet in aqueous solution of a univalent copper, the absorption maximum of this violet solution being at 565mμ (ε 8, 000), and limit of detection, 0, 02 γ/cc. The solution followed the Beer's law when concentration of copper was below 20γ/cc., the color being stable at pH 3-13 and a temperature below 65°. There was no change in absorbance even after two days under these conditions. This coloration is not interfered by the presence of alkali metals, alkaline earth metals, NH
4+, Cl
-, NO
3-, SO
42-, AcO
-, and H
2PO
4-. Some interference is observed in the presence of metals which form sparingly soluble hydroxides, CO
32-, and BO
2-, but their effect can be removed by dilution.
抄録全体を表示