Abstract:Boron gypsum has been widely used in cement and asphalt mixed materials in recent years. Its main components are CaSO4·2H2O, B2O3 and other impurities. Therefore, accurate and rapid determination of boron in gypsum samples is of great significance for the application and comprehensive utilization of gypsum resources. However, there is no chemical analysis method of boron in GB/T 5484-2012 Gypsum Analysis Method, and there are few related literature reports. At present, the determination of boron is mainly by inductively coupled plasma mass spectrometry (ICP-MS), and the sample pretreatment is mostly by acid solution, while the alkali fusion method is not used much. The main reason is that a large amount of salt is produced in the solution after alkali fusion, which affects the stability of plasma flame, and 732 cation exchange resin can absorb a large number of sodium ions. At the same time adsorbed calcium, nickel, iron and rare earth cations, reduce salt interference. Based on this principle, an ICP-MS method for the determination of boron in gypsum was established by using sodium hydroxide alkali melt -732 type cation exchange resin for exchange and separation, and rhodium internal mark was added online. At the same time, since the national standard material of gypsum does not contain boron content, High purity calcium sulfate was mixed with rock reference material, river sediment national reference material and soil national reference material to form artificial reference material, and the experimental conditions such as melting system, cationic addition amount and adsorption time, cleaning solution and isotope selection were discussed. The detection limit of this method is 0.76μg/g, the precision (RSDS, n=7) is 0.9%~1.7%, the relative errors are 1.56%~3.96%, and the recoveries are 97.5%~102%. The method is rapid, accurate and suitable for the determination of boron in gypsum.