Determination of phoshorus in tobacco with phosphovanamolybdate blue spectrophotometry

A new phosphovanamolybdate blue spectrophotometric method for the determination P in tobacco was studied. The mothod is based on the color reaction of fructose reduced phosphovanamolybdate yellow in sulfuric acid medium. The maximum absorption wavelength of the phosphovanamolybdate blue is 810nm.The value of molar absorption coefficient is 1.94×10⁴mol ^-1cm ^-1. Beer's Law is obeyed in the rang of 0~30 μg/25ml for P. The recovery of phosphorus was 98.6%~103.2%.