Ultra-trace determination of 90Sr, 137Cs, 238Pu, 239Pu, and 240Pu by triple quadruple collision/reaction cell-ICP-MS/MS: Establishing a baseline for global fallout in Qatar soil and sediments

Abstract

The development of practical, fast, and reliable methods for the ultra-trace determination of anthropogenic radionuclides 90Sr, 137Cs, 238Pu, 239Pu, and 240Pu by triple quadruple collision/reaction cell inductively coupled plasma mass spectrometry (CRC-ICP-MS/MS) were investigated in term of its accuracy and precision for producing reliable results. The radionuclides were extracted from 1 kg of the environmental soil samples by concentrated nitric and hydrochloric acids. The leachate solutions were measured directly by triple quadrupole CRC-ICP-MS/MS. For quality assurance, a chemical separation of the concerned radionuclides was conducted and then measured by single quadrupole-ICP-MS. The developed methods were next applied to measure the anthropogenic radionuclides 90Sr, 137Cs, 238Pu, 239Pu, and 240Pu in soil samples collected throughout the State of Qatar. The average concentrations of 90Sr, 137Cs, 238Pu, 239Pu, and 240Pu were 0.606 fg/g (3.364 Bq/kg), 0.619 fg/g (2.038 Bq/kg), 0.034 fg/g (0.0195 Bq/kg), 65.59 fg/g (0.150 Bq/kg), and 12.06 fg/g (0.103 Bq/kg), respectively.