Determination of two short-lived radioisotopes (radium-226, lead-210) by inductively coupled plasma mass spectrometry (ICP-MS) in environmental matrices.

摘要

Inductively coupled plasma mass spectrometry (ICP-MS) was found to be a suitable analytical method for the determination of two short-lived radionuclides, 210Pb and 226Ra, providing detection levels in the mBq (fg) range. Analytical protocols, specific for each radioanalyte and developed specifically for mass spectrometry measurements, were tested on numerous environmental matrices. The main issues associated with the determination of naturally occurring radionuclides by mass spectrometry (presence of interferences and low environmental concentrations) have been thoroughly investigated. Ion and extraction chromatography and pre-concentration on adsorption media are solutions proposed and studied to deal with both issues. Isobaric, molecular, and non-spectral interferences were investigated and solved using newly developed analytical protocols and unique mathematical and instrumental tools such as unique sample loading systems (APEX, ARIDUS, or Thermal Desorption Unit). Many instruments were tested (ELAN-5000, ELAN-DRCII, Platform, and Element2) and suitability of each instrument was assessed with respect to 210Pb and 226Ra determination. Determination of 226Ra in liquid (i.e. drinking and well water) and solid samples (i.e. sediments, biological tissues, and ores) was performed using the various protocols developed. 210Pb in drinking water was also measured using a simple sample preparation protocol developed.