Rare earth elements and 143Nd/144Nd isotope ratio measurements using tandem ICP-CRC-MS/MS: characterization of date palm (Phoenix dactylifera L.)

Herein, tandem inductively coupled plasma mass spectrometry with a collision/reaction cell (ICP-CRC-MS/MS) was used to accurately characterize the rare earth element (REE) pattern and the radiogenic isotope ratios of Nd-143/Nd-144. Plant and soil samples were digested with concentrated acids, and the sample solutions were diluted and directly measured using ICP-CRC-MS/MS. Oxygen (O-2) was used to exclude polyatomic interferences with the concerned masses of the REEs. Carbon dioxide (CO2) was introduced into the reaction cell to eliminate the Sm-144 isobar via the indirect mass shift mode from Nd+ to NdO+. The methods were validated by measuring standard reference materials. For quality assurance, the REEs and Nd were chemically separated and then measured using ICP-CRC-MS/MS in a single quad mode, in which the first quadrupole served as only an ion guide. The REE pattern and radiogenic isotope ratios of Nd-143/Nd-144 were identified in date palm (Phoenix dactylifera L.) obtained from three countries in the Arabian Peninsula: Qatar, Kuwait, and Saudi Arabia.