Secchiari Arianna, Toffolo Luca, Recchia Sandro, Tumiati Simone
Dipartimento di Scienze Della Terra, Università Degli Studi di Milano, via Mangiagalli 34, I-20133, Milano, Italy.
Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 11, I-22100, Como, Italy.
Commun Chem. 2025 Jan 23;8(1):19. doi: 10.1038/s42004-024-01370-5.
Validating thermodynamic models is essential in experimental geosciences for exploring increasingly complex systems and developing analytical protocols. However, investigating solid-fluid equilibria in mm-sized experimental capsules poses several challenges, particularly in sulfur-bearing chemical systems. These include maintaining bulk fluid composition and performing quantitative analysis with extremely low amounts of synthesized fluid. We present an innovative methodology for measuring ultra-low amounts of sulfur volatiles (HS and SO) generated during experimental runs at high pressure and temperature conditions of 3 GPa and 700 °C. Using solid sulfides (FeS + FeS) and water as reactants, we performed redox-controlled syntheses employing a piston cylinder apparatus. We demonstrate that ex-situ measurements of these fluids by quadrupole mass spectrometry ensure accurate and precise analysis, confirming predicted thermodynamic compositions. This methodology allows in-depht investigation of sulfide solid-fluid equilibria, shedding light on sulfur volatiles behavior and geochemical cycles under high P-T conditions characteristic of the Earth's interior.
验证热力学模型对于实验地球科学探索日益复杂的系统和开发分析方案至关重要。然而，研究毫米尺寸实验胶囊中的固液平衡存在诸多挑战，尤其是在含硫化学系统中。这些挑战包括维持流体总体成分以及对极少量合成流体进行定量分析。我们提出了一种创新方法，用于测量在3吉帕和700°C的高压和高温条件下实验运行过程中产生的极少量硫挥发物（HS和SO）。使用固体硫化物（FeS + FeS）和水作为反应物，我们采用活塞圆筒装置进行了氧化还原控制的合成。我们证明，通过四极质谱对这些流体进行非原位测量可确保准确精确的分析，证实预测的热力学组成。这种方法允许对硫化物固液平衡进行深入研究，揭示地球内部特征的高P-T条件下硫挥发物的行为和地球化学循环。
