The effect of instrumental mass bias on δ11B measurements:: a comparison between thermal ionisation mass spectrometry and multiple-collector ICP-MS

A series of synthetic samples which span the range of known delta(11)B values have been measured by thermal ion mass spectrometry (positive and negative ion) and by multiple-collector ICP-MS (Axiom and IsoProbe) in order to assess the effects of mass bias on delta(11)B values. The IsoProbe shows the highest mass bias, but yields delta(11)B values identical to those obtained with the Axiom and by TIMS measurements, indicating that mass bias has no detectable effect on delta(11)B values. Measurements carried out by multiple-collector ICP-MS yield higher precision than TIMS measurements. Typically multiple-collector ICP-MS measurements offer a 50% improvement in precision over positive ion TIMS and nearly one order of magnitude better than that for negative ion TIMS. (C) 2004 Elsevier B.V. All rights reserved.