抄録
This study was carried out for the purpose of dividing SH groups detected in the wool, treated with thioglycollic acid (TGA), into two parts; combined cysteine residues and free SH groups of adsorbed TGA. The Human's polarographic method was applied in which p-chloromercuribenzoic acid (P-CMB) is used and no hydrolysis process is taken up. Some fundamental conditions were decided for detecting SH of TGA-treated wool as follows:
1) It was capable to draw a clear line between each 1st wave of P-CMB and of its mercaptide produced by mixing P-CMB with TGA at about 9 of PH value of electrolytic solution.
2) P-CMB mercaptide of cysteine is detected from the solution when cystine and P-CMB are mixed in alkaline medium. It is, therefore, desirable to treat the wool with P-CMB at as low pH value as possible and to proceed polarographic process after removing the wool and rising the pH value of the remaining solution to 9.
3) The reaction of wool with P-CMB must, however, be avoided at lower pH values than 7 as P-CMB and particulaly its mercaptide are unstable in acidic medium.
4) The absorbed P-CMB and mercaptide in wool gains in quantity with the increase of the concentration of used P-CMB. It is necessary, therefore, to repeat polarographic process again on the buffer solution of another vessel in which the wool sample is dipped after the preceeding treatment.
Thus, it may be concluded that the content of total-SH will be accounted from the decrease of 1st. wave height of P-CMB, of free SH from 1st. wave height of mercaptide and of combined SH from the difference between the former and the latter.
