analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA-ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Association of Geoanalysts (IAG). The reference values were derived from the results of 16 independent techniques, including definitive (isotope dilution) and comparative bulk (e.g., INAA, ICPMS, SSMS) and microanalytical (e.g., LA-ICPMS, SIMS, EPMA) methods. Agreement between two or more independent methods and the use of definitive methods provided traceability to the fullest extent possible. We also present new and recently published data for the isotopic compositions of H, B, Li, O, Ca, Sr, Nd, Hf, and Pb. The results were mainly obtained by high-precision bulk techniques, such as TIMS and MC-ICPMS. In addition, LA-ICPMS and SIMS isotope data of B, Li, and Pb are presented.

Identifying natal origins of marine fishes is challenging because of difficulties in conducting mark-recapture studies in marine systems. We used natural geochemical signatures in otoliths (ear bones) to determine natal sources in weakfish (Cynoscion regalis), an estuarine-spawning marine fish, in eastern North America. Spawning site fidelity ranged from 60 to 81%, comparable to estimates of natal homing in birds and anadromous fishes. These data were in contrast to genetic analyses of population structure in weakfish. Our findings highlight the need for consideration of spatial processes in fisheries models and have implications for the design of marine reserves in coastal regions.

Sulfur isotope ratios (34S/32S ) were determined by means of inductively coupled plasma double focusing sector field mass spectrometry (ICP-SMS) operated in the medium resolution mode (m/Dm=4000) using a torch with a platinum guard electrode and a microconcentric nebulizer combined with a membrane desolvation unit. The guard electrode together with the nebulizing unit increased the signal intensity of the measured isotopes by two orders of magnitude. The use of the membrane desolvation unit decreased the signal intensity of the corresponding interference (mainly oxygen containing species) significantly. Detection limits in solution of 0.01 ng g−1, limited only by blank levels, could be achieved. Moreover, sulfur isotope ratios could be determined at concentration levels down to 1 ng g−1 with a precision of better than 0.1% relative standard deviation (RSD) (n=10). A precision of 0.04% RSD could be achieved at higher concentration levels. ICP-SMS has been shown to be an excellent tool for fast and precise isotope ratio measurements in combination with a high sample throughput and minimum sample preparation prior to analysis. measurements27 and secondary ion mass spectrometry, which

No abstract

ICP mass spectrometry is being increasingly used for isotopic analysis and for element determination by means of isotope dilution. For accurate isotope ratio determination, both the mass discrimination and the detector dead time have to be appropriately corrected for. For a Finnigan-MAT Element and a Perkin-Elmer SCIEX Elan 5000 ICP mass spectrometer, the constancy of the detector dead time across the mass range was systematically investigated. For the Element, which is equipped with a conversion dynode and a secondary electron multiplier with discrete dynodes, the dead time was observed to be independent of the analyte mass number. For the Elan 5000, however, which is equipped with a Channeltron-continuous dynode-electron multiplier, the detector dead time was observed to be strongly mass-dependent. The decreasing gain of Channeltron electron multipliers with increasing ion mass may be at the origin of the behaviour established. This observation has to be taken into account when highly accurate isotope ratio measurements are required and hence the detector dead time has to be properly determined and corrected for

No abstract

No abstract

The quantification capabilities for sulfur microanalysis in quartz-hosted fluid inclusions were investigated with laser ablation (LA) inductively coupled plasma quadrupole mass spectrometry (ICP-Q-MS) and ICP sector field mass spectrometry (ICP-SF-MS) allowing resolution of sulfur from polyatomic interferences. A scapolite mineral sample was used to determine the sulfur concentration in NIST SRM 610 (570 AE 70 mg g À1 ), which was further validated using EPMA and then used as standard reference material for the fluid inclusion analysis. The sulfur concentration in an assemblage of brine inclusions from a quartz-molybdenum vein was determined to be 5900 AE 2000 mg g À1 measuring 17 inclusions with the ICP-SF-MS and 13 inclusions with the ICP-Q-MS instrument. The agreement between the two ICP-MS instruments for sulfur was $5% and well within the overall precision of 35% relative standard deviation. The precision and accuracy was not limited by interferences, but by a so far unknown sulfur contamination source when ablating the host mineral quartz. Due to this contamination, a careful baseline correction is necessary which is described and discussed in detail. Nevertheless, the method developed to determine sulfur maintains the multi-element capabilities for individual fluid inclusions. Limits of detection for sulfur are correlated with the inclusion mass and were found to be $ 30-100 mg g À1 for 60 mm inclusions.