Determination Of Organophosphorus Content In Nickelous Sulfate And Cobalt Dichloride Solution & Study On Analytical Method Of Impurity Elements In Rhodium

The dissertation is mainly composed of the following three parts:1. Determination of organophosphorus content in nickelous sulfate and cobalt dichloride extraction surplus solution with heteropoly phosphate-molybdic acid spectrophotometric method.Micro-amount of organic phosphor in samples was pre-concentrated and separated with isooctane as extractant. Isooctane was eliminated at low temperature, and then destroyed with perchloric acid. The residue was dissolved in nitric acid. Determinations were proceeded with the following two methods:(1) In 0.65 mol/L-1.63mol/L nitric acid, heteropoly phosphate-molybdic acid created by the reaction of phosphorus and ammonium molybdate was extracted with butyl acetate. It was deoxidized with tin dichloride and then extracted to water. Absorbency was determined in wavelength 680nm. The recoveries of organic phosphorus added to these samples are 97%～103% and relative standard deviation(RSD) is<3%. The proposed method is stable. (2) After pretreatment, phosphorus in samples solution was directly measured by inductively coupled plasma optical emission spectrometry(ICP-AES).2. Simultaneous determination of silicon, iron, magnesium and trace platinum, palladium, iridium, ruthenium, aurum, silver, copper, nickel, aluminium, lead, manganese, chrome, tin, bismuth and zinc contents in high purity rhodium and ammonium rhodium hexachloride by ICP-AES and inductively coupled plasma mass spectrometry(ICP-MS).Rhodium was decomposed through microwave digestion and ammonium rhodium hexachloride was dissolved with high purity water. When Fe,Mg were<0.0005% and Si was<0.001% in samples, standard addtion method was used. The precision is≤13.7% (RSD) and recoveries of addtion standard are 80%～116%. The accuracy of the proposed method was checked by analyzing some standard samples with satisfactory results. Relative errors are＜±21% through comparison determination.3. The study of analytical method of magnesium, manganese, iron, nickel and zinc in high purity ammonium rhodium hexachloride by Zeeman effect electrothermal atomic absorption spectrometric method.The samples were dissolved in diluted hydrochloric acid, and then determined by electrothermal atomic absorption spectrometric method. The contents between 0.00001% and 0.0001% of Mg, Mn, Fe, Ni and Zn in samples were determined with standard addtion method. The recoveries are 89%～113% and relative standard deviation(RSD) is <5%. Relative errors are≤±21% through comparison determination.