Determination of Volatile and Nonvolatile Trace Elements in Geochemical Samples by Fluoride Solid Buffer-AC Arc Direct Reading Emission Spectrometry

Abstract

It is not necessary to digest a sample if it is determined by Arc Direct Reading Emission Spectrometry, and multiple elements can be simultaneously determined by solid injection. Currently used geochemical solid buffers, such as potassium persulfate and sodium fluoride have a low temperature arc flame, and can only analyze silver, boron, tin, molybdenum, lead, copper and other volatile elements but cannot analyze chromium, manganese, titanium and other high boiling point elements. Alkali metal was used to control the low arc temperature, and a solid buffer composed of aluminum fluoride, PCTFE and other high efficiency fluorination compounds was prepared based on the fact that the reaction between difficult volatile elements and fluorine ion under high temperature would have lower excitation energy. By optimizing the choice of line pairs, exposure time, electrode shape and other analysis conditions, 14 volatile and non-volatile elements in the geochemical samples can be simultaneously analyzed. The detection limit of the method ranges from 0.016 to 46.93 μg/g, and the relative standard deviation is 4.1% to 12.3%. The accuracy was verified by national standard material. The results were in accordance with the standard values, and the parameters meet the requirements of geochemical census. The method has high analysis efficiency and is practical in geochemical analysis.

Keywords

• geochemical samples
• volatile elements
• nonvolatile elements
• arc direct reading emission spectrometry
• buffer
• fluorination