Combined Determination of Phosphorus and Arsenic in Molybdenum Concentrate by Molybdenum Blue Spectrophotometric Method

This paper determined the total absorbance of phosphorus molybdenum blue and arsenic molybdenum blue by using the additive property of their absorbance values. By eliminating the interference of arsenic by reduction masking with composite reducing agent Na2SO3-Na2S2O3-KBr, the absorbance of phosphorus could be obtained. Thus, the content of phosphorus and arsenic could be calculated, respectively. The results show that the work curves of this method for phosphorus and arsenic are consistent with Beer’s law when the content of phosphorus and arsenic is 0-0.60ug/mL and 0-2.00ug/mL, respectively. The standard addition recovery rate of phosphorus and arsenic is 98.80%-101.04% and 99.00%-101.50%, respectively. The relative standard deviation of phosphorus and arsenic is less than 4.0% with good accuracy and precision. This method is simple and fast to determine phosphorus and arsenic in molybdenum concentrate, and the results are accurate and reliable.