二苯基碳酰二肼分光光度法测定显影废液中银离子

Spectrophotometric determination of silver ion in developing waste liquor with diphenylcarbazide

在pH5.80～6.70溶液中,紫外光照射下,二苯基碳酰二肼与Ag+作用生成红色的二苯卡巴腙,产物用三氯甲烷萃取后,于557nm波长处有一最大吸收值,Ag+浓度在0～1.12×10-3mol/L时符合比尔定律,据此建立了测定微量Ag+的分光光度法。当测定溶液中1.0×10-3mol/LAg+时,大量Al3+,Fe3+,Fe2+,K+,Na+,Ca2+,Co2+,Ni2+,Mn2+,Cu2+,Zn2+,V(Ⅴ),Ti(Ⅳ),SO42-没有干扰;Cr(Ⅵ)使实验结果偏高,测定前需予先除去。用本法测定显影液中Ag+,相对标准偏差为2.65%,加标回收率为103.6%。

In the solution at pH5. 80-6. 70 and under the illumination of UV radiation,diphenylcarbazide can react with Ag^＋ to produce a red diphenylcarbazone, of which absorption maximum lies at 557nm when diphenylcarbazone is extracted into thrichloromethane. Beer＇s law is obeyed in the concentration range of 0-1.12 × 10^-3 mol/L for Ag^＋. In view of the above, a spectrophotometry for the determination of Ag^＋ is founded. Larger quantities of Al^3＋ , Fe^3＋ , Fe^2＋ , K^＋ , Na^＋ , Ca^2＋ , Co^2＋ , Ni^2＋, Mn^2＋ ,Cu^2＋ ,Zn^2＋ ,V（Ⅴ）, Ti（Ⅳ） and SO4^2- do not interfere in the delermination. However,the presence of Cr（Ⅵ）enhances the determination results, so it is necessary to remove before the determination. This method is employed to the determination of Ag^＋ in developing waste liquor with the relative standard deviation of 2.65% and the recovery of 103.6%.