Characterization of the analytical performance of δ N and δ O measurements by the silver nitrate method in the framework of nitrate source apportioning.

Rationale: Nitrate pollution represents one of the most important issues for ground and surface water quality and source identification is essential for developing effective mitigation practices. Nitrate isotopic fingerprinting can be utilized to identify the sources of nitrate pollution in aquifers. However, it is crucial to assess the performances (precision and accuracy) of the analytical procedure applied to measure the δ N and δ O values of nitrates from field samples to correctly apply this tool.

Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica.

The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level cannot be fully explained by Greenland Ice Sheet melt (∼2 m), ocean thermal expansion, and melting mountain glaciers (∼1 m), suggesting substantial Antarctic mass loss was initiated by warming of Southern Ocean waters, resulting from a weakening Atlantic meridional overturning circulation in response to North Atlantic surface freshening.

Measurement of δ13C values of soil amino acids by GC-C-IRMS using trimethylsilylation: a critical assessment.

In this study, we evaluated trimethylsilyl (TMS) derivatives as derivatization reagents for the compound-specific stable carbon isotope analysis of soil amino acids by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). We used non-proteinogenic amino acids to show that the extraction-derivatization-analysis procedure provides a reliable method to measure δ(13)C values of amino acids extracted from soil. However, we found a number of drawbacks that significantly increase the final total uncertainty.

The privileged burial of the Pava Pieve (Siena, 8th Century AD).

Rationale: The 6(th) archaeological excavation campaign performed at the 'Pieve di Pava' (San Giovanni d'Asso, Siena, Italy) unearthed a privileged stone burial of a single individual (US 2378), covered by a monolithic slab and placed in front of an altar. The skeletal remains of a young male (18-20 years old), not in anatomical connection, were found at the bottom floor of a tomb (160 cm long, 40 cm large and over 70 cm deep).

Methods: A multidisciplinary study has been carried out concerning that privileged bone burial.

An isotopic method for testing the influence of leaf litter quality on carbon fluxes during decomposition.

During microbial breakdown of leaf litter a fraction of the C lost by the litter is not released to the atmosphere as CO(2) but remains in the soil as microbial byproducts. The amount of this fraction and the factors influencing its size are not yet clearly known. We performed a laboratory experiment to quantify the flow of C from decaying litter into the soil, by means of stable C isotopes, and tested its dependence on litter chemical properties.

Paleodiet characterisation of an Etrurian population of Pontecagnano (Italy) by Isotope Ratio Mass Spectrometry (IRMS) and Atomic Absorption Spectrometry (AAS)(#).

Human bones recovered from the archaeological site of Pontecagnano (Salerno, Italy) have been studied to reconstruct the diet of an Etrurian population. Two different areas were investigated, named Library and Sant' Antonio, with a total of 44 tombs containing human skeletal remains, ranging in age from the 8th to the 3rd century B.C.

Sampling soil-derived CO2 for analysis of isotopic composition: a comparison of different techniques.

A new system for soil respiration measurement [P. Rochette, L.B.