Extraction-spectrophotometric determination of small amounts of boron in copper metal and copper-base alloys with methylene blue

A sensitive and rapid spectrophotometric method for the determination of small amounts of boron in copper metal and some copper alloys is described. The method is based on the extraction of a BF(4)(-)-Methylene Blue complex into dichloroethane after decomposition of the sample with hydrogen peroxide and sulphuric acid. The optimum reaction conditions and the influence of alloying elements have been investigated. Boron contents in the range 0.00-0.1% can be determined with a relative error ranging from about 9 to 2%.