QUANTITATIVE DETERMINATION OF TRACE ARSENIC BY REDUCTION EVAPORATION-FLAME ATOMIC ABSORPTION PHOTOMETRY METHOD

摘要

PURPOSE:To improve the accuracy of quantitative analysis by reducing the arsenic existing as pentad cations in a sample soln. to tervalent cations by adding titanium trichloride to the soln., evaporating the cations as hydrogenated arsenic, and analyzing quantitatively trace arsenic. CONSTITUTION:The standard soln. of the pentad cations (As+5) is prepd. from sodium arsenate and is taken into a hydride generator. Hydrochloric acid and sulfuric acid and added thereto to prepare the aq. strong acidic soln. to which a titanium trichloride soln. and an aq. potassium iodide soln. of a reduction accelerator are added to reduce As+5 to As+3. The ions are brought into reaction with the hydrogen of the nascent state generated by adding zinc dust thereto to form the gaseous hydrogenated arsenic which is then introduced into an argon-hydrogen flame to measure the absorption of atoms. The quantitative analysis of the trace arsenic is thus made possible with high accuracy.