Innovative sample preparation method using a conductively heated digestion system for trace element analysis of radioactive oil sludge by ICP-OES

Abstract

This study presents a novel and efficient sample preparation method based on conductively heated digestion in closed vessels (CHDS), employing collagen capsules as a transfer medium. The method was specifically developed for the treatment of oil sludge—a complex waste product generated by the oil industry, typically composed of hydrocarbons, water, sediments, processing residues, and radionuclides from the uranium-238 and thorium-232 decay chains. Compared to conventional open-vessel digestion techniques using heating blocks, this approach offers several advantages, including reduced sample and reagent volumes, significantly shorter preparation times, and minimized contamination risks. Trace element concentrations in the digested samples were determined by inductively coupled plasma optical emission spectrometry (ICP-OES).