ID‐TIMS Sm‐Nd and Sr Isotope Ratios of Reference Material Basalt Ribeirão Preto (BRP‐1)

This work presents Sm‐Nd and Sr isotopic ratios of the BRP‐1 (“Basalt Ribeirão Preto”) reference material (RM) based on repeated TIMS measurements over twelve years carried out by the LAGIR laboratory, Brazil. The BRP‐1 RM was produced by the Brazilian Geological Survey from a ca. 130 Ma within‐plate basalt, collected from a quarry near Ribeirão Preto city in the Paraná basin. Isotope ratios were measured using a TRITON mass spectrometer. Instrumental bias and fractionation corrections were performed based on repeated measurements of the certified RMs JNdi‐1 and NIST SRM 987. The measured Nd and Sr isotopic ratios of BRP‐1 are: 143Nd/144Nd = 0.512408 ± 0.000010 (2s), and 87Sr/86Sr = 0.706011 ± 0.000017 (2s). The mass fractions of Sm and Nd are 11.0 ± 0.2 and 51.9 ± 0.6 μg g‐1, respectively, showing no significant differences compared with the accepted values from the literature. No significant difference between measurements was observed, whether digesting samples in single or batch mode, using metal‐jacketed PTFE bombs or PFA vials, or with or without the addition of a spike. The accuracy of these results was evaluated through the measurement of well‐characterised USGS RMs, such as AGV‐1, BCR‐1, BHVO‐1, G‐2 and GSP‐1. Key Points The isotopic ratios recommended in this study for the Brazilian basalt BRP‐1 RM are 143Nd/144Nd = 0.512408 ± 0.000010 (2s) and 87Sr/86Sr = 0.706011± 0.000017 (2s). No significant differences in the BRP‐1 RM results were shown regarding different digestion conditions. The reliability of the BPR‐1 measurements was achieved through analyses of USGS RMs, which show good reproducibility in comparison with literature values.