Permo-Triassic unconformity- related Au-Pd mineralisation, south Devon, UK : new insights and the European perspective

An integrated mineralogical-geochemical study of unconformity-related Au-Pd occurrences within and around the Permo–Triassic basins of southwest England, UK, has confirmed the importance of low temperature (86±13°C), hydrothermal carbonate veins as hosts for the mineralisation. Fluid inclusion data for the carbonate gangue, supported by stable isotope (13C and 18O) and radiogenic (87Sr/86Sr) data, have identified three principal fluids: (1) a reducing calcic brine [>25 wt% salinity, 2)] originating in the sub-unconformity basement and an expression of advanced mineral–fluid interaction; (2) an oxidising sodic brine [~16 wt% salinity, >0.9 NaCl/(NaCl+CaCl2)] originating in the post-unconformity red beds under evaporitic conditions, and (3) an oxygenated, low salinity groundwater (<3 wt% salinity).="" the="" sodic="" brine="" is="" reasoned="" to="" be="" the="" parent="" metalliferous="" fluid="" and="" to="" have="" acquired="" its="" enrichment="" in="" au="" and="" pd="" by="" the="" leaching="" of="" immature="" sediments="" and="" intra-rift="" volcanic="" rocks="" within="" the="" local="" permo–triassic="" basins.="" metal="" precipitation="" is="" linked="" to="" the="" destabilisation="" of="" au="" and="" pd="" chloride="" complexes="" by="" either="" mixing="" with="" calcic="" brines,="" dilution="" by="" groundwaters="" or="" interaction="" with="" reduced="" lithologies.="" this="" explains="" the="" diversity="" of="" mineralised="" settings="" below="" and="" above="" the="" unconformity="" and="" their="" affinity="" with="" red="" bed="" brines.="" the="" paucity="" of="" sulphide="" minerals,="" the="" development="" of="" selenides="" (as="" ore="" minerals="" and="" as="" mineral="" inclusion="" in="" gold="" grains),="" the="" presence="" of="" rhodochrosite="" and="" manganoan="" calcites="" (up="" to="" 2.5 wt%="" mn="" in="" calcite)="" and="" the="" co-precipitation="" of="" hematite="" and="" manganese="" oxides="" are="" consistent="" with="" the="" overall="" high="" oxidation="" state="" of="" the="" ore="" fluids.="" a="" genetic="" model="" is="" proposed="" linking="" permo–triassic="" red="" beds,="" the="" mixing="" of="" oxidising="" and="" reducing="" brines,="" and="" the="" development="" of="" unconformity-related="" precious="" metal="" mineralisation.="" comparison="" with="" other="" european="" permo–triassic="" basins="" reveals="" striking="" similarities="" in="" geological="" setting,="" mineralogy="" and="" geochemistry="" with="" au,="" au-pd="" and="" selenide="" occurrences="" in="" germany="" (tilkerode,="" korbach-goldhausen),="" poland="" (lubin)="" and="" the="" czech="" republic="" (svoboda="" nad="" úpou="" and="" stupná).="" though="" the="" known="" au-pd="" occurrences="" are="" sub-economic,="" several="" predictive="" criteria="" are="" proposed="" for="" further=""

Further development of a liquid chromatography–high‐resolution mass spectrometry/mass spectrometry‐based strategy for analyzing eight biomarkers in human urine indicating toxic mushroom or Ricinus communis

Recently, we presented a strategy for analysis of eight biomarkers in human urine to verify toxic mushroom or Ricinus communis ingestions. However, screening for the full panel is not always necessary. Thus, we aimed to develop a strategy to reduce analysis time and by focusing on two sets of analytes. One set (A) for biomarkers of late-onset syndromes, such as phalloides syndrome or the syndrome after castor bean intake. Another set (B) for biomarkers of early-onset syndromes, such as pantherine–muscaria syndrome and muscarine syndrome. Both analyses should be based on hydrophilic-interaction liquid chromatography coupled with high-resolution mass spectrometry (MS)/MS (HILIC-HRMS/MS). For A, urine samples were prepared by liquid–liquid extraction using dichloromethane and subsequent solid-phase extraction of the aqueous supernatant. For B urine was precipitated using acetonitrile. Method A was validated for ricinine and α- and β-amanitin and method B for muscarine, muscimol, and ibotenic acid according to the specifications for qualitative analytical methods. In addition, robustness of recovery and normalized matrix factors to matrix variability measured by urinary creatinine was tested. Moreover, applicability was tested using 10 urine samples from patients after suspected mushroom intoxication. The analytes α- and β-amanitin, muscarine, muscimol, and ibotenic acid could be successfully identified. Finally, psilocin-O-glucuronide could be identified in two samples and unambiguously distinguished from bufotenine-O-glucuronide via their MS2 patterns. In summary, the current workflow offers several advantages towards the previous method, particularly being more labor-, time-, and cost-efficient, more robust, and more sensitive