Ion Exchanger Colprimetry in Direct Determination of Minor Elements in Sea water——Micro Determination of Cadmium and Chromium in Sea water

This article is a study of the new method of direct determination of minor cadmium and chromium in seawater by means of colorimetry,using reline of Chinese manufacture.The basis of this method is that ion exchanger is a translucent body,which enriehes in diluted solutions and can be subjected to direct spectrophotometric determination,under certain conditions,after colouring appears on it,making it unnecessary to get its eluate for examination.Experiments prove that as to systems with high distribution ration,their density as against the concentration of resinphase sample complex to be identified shows a straight line relationship,and similarly with their density against the primary concentration in liquid phase.This is the basis of the quantitative analysis of this new method,which is tens of times higher in sensitivity than the conventional colorimetry of liquide.Its ease of manipulation,elimination of the use of expensive instruments (e.g.in our experiments speotrophotometer type 721.of Chinese manufacture was used) and poisonous reagents makes it suitable for exteasive adoption with promising prospects,such as for enviromental analysis.