The quantitative determination of hypo in photographic prints with silver nitrate

A silver nitrate test is described for the quantitative determination of residual hypo in photographic prints. The hypo is converted in situ to silver sulfide, the transmission density of the sulfide determined, and the hypo content obtained by reference to a standard curve.The method used to establish the standard curve is outlined, the data being verified by quantitative analyses.A simplified procedure is suggested involving the application of a drop of silver nitrate to the back of the print and then matching the spot visually with a set of standards.     

室温下硫化银的制备及表征

文章采用两种方法合成了Ag2S:以溅射过银的导电玻璃、硫粉和NaOH为反应物,在水中合成了Ag2S;以溅射过银的导电玻璃、硫粉和叔丁醇钾为反应物,在乙醇中合成了Ag2S。采用X射线衍射(XRD)和扫描电子显微镜(SEM)对Ag2S的形貌以及晶体结构进行了表征。结果表明,制备出的Ag2S分别为1μm左右的颗粒和为30nm左右的小颗粒,均为单斜结构。