Abstract: A new ion-exchange material [based on poly(acrylic acid)] and some of its analytical applications have been reported. This paper contains data on the ion-exchange properties of the film form of the material and its potential application to the decontamination of wastewater and drinking water. The film has a high exchange capacity of 5-6 meq./g and a pKa of 5.7. The calcium form is the most effective for removing metal ions from solution, and the optimum pH range is between 5 and 7. The exchange rates are slower for the film form than for the bead and powder forms of the ion-exchange material; otherwise, the properties are similar. The film is effective when hard water solutions are employed and also when metal ions are in the complex matrix of wastewater from electroplating. The film can be used in flow systems having a flow channel large enough to allow passage of turbid solutions.

Abstract: The cited method is based on the formation of heteropoly blue by the reduction of the yellow heteropoly complex β-molybdosilicic acid. Modifications made include removal of Bi interferent in sample preparation and removal of the HF matrix in flow injection. The cited method compared well with standard spectrophotometric and ICAP methods but results were not in agreement with calculated compositions. A spectrophotometric flow injection method for the determination of silicate based on heteropoly blue formation is presented. The proposed reagent gives a wider dynamic range than previously reported flow injection procedures. The Bi interference reported for the spectrophotometric method is eliminated in sample preparation, and the method is applied to the determination of Si in Bi borosilicate glass. Results are compared with spectrophotometric and inductively coupled Ar plasma emission spectrometric determinations