ANALYSIS OF TRACE INDIUM BY FLAMELESS ATOMIC ABSORPTION METHOD

摘要

PURPOSE:To suppress volatilization of indium in incineration as much as possible and thereby to improve detection sensitivity by a method wherein a water solution of rhodium nitrate is added to a sample and subjected to incineration and then atomization. CONSTITUTION:A sample is injected into a graphite tube 1 from a sample injection port 1b, while a solution of rhodium nitrate is added subsequently, and these two kinds of liquids are accumulated in a sample accommodating element. Then, a heat is generated by electrification from electrodes 2 and 3, the temperature of the tube 1 is thereby increased to dry up the water in the solution of the sample and the rhodium nitrate, and further it is increased, so that the incineration is effected. Then the rhodium nitrate Rh(NO3)3 changes into a rhodium oxide Rh2O3 and reacts with indium in the sample, and thereby a thermally stable double oxide InRhO3 is formed. Accordingly, volatilization of this indium at the temperature of incineration is suppressed by a matrix modifying effect. When the temperature is increased to the one suitable for analysis after the completion of incineration, the indium is subjected to thermal decomposition to be atomized and causes light absorption.