Spectrophotometric Determination of Phosphorus in Steel by the Malachite Green-Phosphorus Antimony Molybdenum Heteropoly Acid

Determination of phosphorus in steel was established by spectrophotometry of malachite greenphosphorus antimony molybdenum heteropoly acid in microemulsion medium of OP/n-C5H11OH/C7H16/H2 O.The influence of the Chromogenic time,usages of Chromogenic agent,microemulsion and acid in the Chromogenic reaction was researched.The results indicate that the maximum absorption wavelength of ion association complex is 660 nm.The apparent molar absorptivity is 9.4×104 L·mol-1·cm-1,and Beer's law is obeyed in the P concentration range of 0.04~0.44μg/mL.Ratio of complexation of malachite green and phosphorus antimony molybdenum is 4∶1.Compared with the corresponding traditional determination method of phosphorus,it has higher sensitivity.The 14 kinds of common ions have almost no interference to reactions.RSD is less than 3% in the determination of phosphorus on steel samples.