POTENTIOMETRIC TITRATION OF PERCHLORATE WITH TETRAPHENYLARSONIUM CHLORIDE AND A PERCHLORATE ION SPECIFIC ELECTRODE

A number of organometallic salts have been used to measure the perchlorate anion. Both electrometric and gravimetric methods have been employed. This paper reports a potentiometric precipitation titration of perchlorate with tetraphenylarsonium chloride. The titration is followed with a perchlorate ion specific electrode and a double-junction calomel electrode. Best results are obtained with solutions between pH 4 and 7. The method is simple, rapid, and free from common interferences. However, extremely large amounts of some simple anions distort curve shapes and require adjustment in the titrant standardization. Accuracy and precision of the method for assaying simple perchlorate salts are equivalent to or better than available methods. Based on replicate analyses of three perchlorate samples, overall 95% confidence limits were ±0.16%. In addition, the perchlorate electrode was found to respond linearly to permanganate, dichromate, and periodate ions over an appreciable concentration range. © 1968, American Chemical Society. All rights reserved.