Micro flow injection ICP-MS analysis of high matrix samples: an investigation of its capability to measure trace elements in iron meteorites

International audienceThe coupling of a micro-flow injection sample introduction system to a highly versatile quadrupole ICP-MS(FI-ICP-MS) has been demonstrated to achieve accurate and precise trace element measurements forseveral iron meteorites. Measurements were made for the trace siderophile elements, Ru, Au, Rh, Pd, Ir,Pt, Ga, Cr, Cu and Re, where results present good agreements for most metals to duplicate samples alsomeasured by a sector-field ICP-MS (ICP-SFMS). A major advantage for trace element measurements byflow-injection ICP-MS is the added flexibility to increase the total dissolved solids (TDS) concentrationsof the working solutions above the 2000 mg g1 ICP-MS limit. The FI-ICP-MS technique used in thisstudy allowed the sample digests to be measured directly, where the TDS concentrations were 2.5 timesthe above limit. The data generated clearly demonstrate that the micro-flow inputs of the high matrixmaterial never overloaded the plasma or compromised on instrument performance. Without the needfor extra dilutions a better detection capability for most elements was found in comparison to thosemade by the ICP-SFMS, where all method detection limits were below 0.1 mg g1, apart from Ru and Ga.Furthermore, it was evident from the reduced sample preparation time, together with measurementtimes of less than 7 minutes per sample, that the FI-ICP-MS analysis was a much more rapid technique.The accuracy of the FI-ICP-MS technique was tested from the measurement of two synthetic ironmeteorites. A selection of elements, including Cr, Ga, Ru, Ir and Re, gained absolute error values betterthan 5%, where Re, the analyte with the lowest concentration, reported the lowest absolute error, witha value of less than 1%. Precision, determined from two times the relative standard deviation of repeatmeasurements of the synthetic solutions (n ¼ 7), gained values less than 10% for all elements