The rhenium-osmium (Re-Os) isotopic dating technique has been extensively applied for the precise geochronological determination of black shale formations, effectively overcoming difficulties in dating chronologically challenging strata.Recent advancements have extended this methodology to limestone systems with substantially lower Re and Os concentration, thereby providing novel technical approaches for dating carbonate sequences.Clarifying the Re distribution in limestone is critical for optimizing experimental protocols and enhancing the accuracy and precision of dating results.However, carriers of Re and Os in carbonate rocks, particularly the radioactive parent element Re, remain poorly constrained.This study investigated Permian limestone samples from Guangde, Anhui Province, via integrated mineralogical characterization using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) and femtosecond laser ablation-inductively coupled plasma mass spectrometry (fs-LA-ICP-MS).The analytical results indicated that Re is predominantly hosted in authigenic phases such as organic matter (OM) and pyrite.Terrigenous quartz contains little to no Re, while calcite does not host Re.These findings emphasize that Re-Os pretreatment protocols should prioritize the complete dissolution of OM and pyrite, while avoiding the dissolution of silica phases.

The present study optimized the planetary ball milling of synthetic pyrrhotite doped with trace metals in order to enhance homogeneity.It has been demonstrated that milling at 400 rpm with acetone is an effective method of reducing particle size, whilst also preventing oxidation and secondary phase formation, in contrast to the process of dry grinding.Annealed samples demonstrated excellent trace element uniformity (RSD ~2-3%) by LA-ICP-MS, comparable to or superior to existing standards.The work underlines the pivotal role of milling conditions in the production of reliable sulfide standards, which are essential for accurate analysis in geochemistry and materials science.

Membrane filtration is an efficient technique for rapid and precise separation, yet challenges persist in distinguishing and selectively separating nanoparticles with identical elemental compositions, especially copper-based nanoparticles.Here, we report for the first time the immobilization of thiol-functionalized Fe3O4 nanoparticles (Fe3O4 -RSH NPs) onto mixed cellulose ester membranes for the selective separation and preconcentration of copper nanoparticles (Cu NPs).The Fe3O4-RSH NPsmodified membrane demonstrated significantly greater retention of Cu NPs than CuS and CuO NPs of comparable size.The functionalized membrane exhibits exceptional separation performance, achieving over 90% retention of Cu NPs and an enrichment factor of ~23, as verified by inductively coupled plasma mass spectrometry (ICP-MS).Notably, the retention rate of Cu NPs remained unaffected by other copper species, demonstrating the excellent selectivity of the modified membrane toward Cu NPs.Under optimized conditions, the method reached a limit of detection (LOD) of 2.2 pg mL for Cu NPs.Furthermore, the approach enabled successful detection of Cu NPs in river water samples from Chengdu.This strategy provides a rapid, reliable, and cost-effective pretreatment method for trace nanoparticle analysis in environmental samples and offers a promising platform for the development of low-cost, on-site nanoparticle monitoring technologies.

Boron nanoparticles (BNPs) are currently being considered for use in boron neutron capture therapy.A method is proposed for determining the boron content in the organs and tissues after BNPs administration to laboratory animals without dissolution and preliminary freeze drying of samples.It is proposed to ash biological samples in tubular quartz furnace and analyze the resulting powders using two-jet plasma optical emission spectrometry (TJP OES).The conditions for sample preparation and quantitative analysis were optimized: ashing temperature of 400 C for 3 h; boron line for determination is 249.67 nm.The boron limit of quantification in different tissues ranged from 5 to 200 ng g -1 .The accuracy of the proposed method was confirmed by spike experiments; boron recovery is not less than 97%.The method was developed for the analysis of tumors, brain, skin, muscle, kidneys, liver and spleen.However, the method can be applied to the analysis of other organs and tissues (including other animals -rats, hamsters, and others).The first data on the biodistribution of boron after 0.5, 1 and 2 h of intraperitoneal administration of BNPs stabilized in hyaluronic acid are presented.The maximum boron content at each time point was determined in the spleen (20, 3.0, and 6.6 %ID g -1 after 0.5, 1 and 2 h, respectively), in the tumor -0.11 %ID g -1 after 0.5 h.

The performance of a nitrogen (N2)-sustained Microwave Inductively Coupled Atmospheric Pressure Plasma (MICAP) ionization source integrated with a Quadrupole Mass Spectrometer (QMS) was characterized.Instrument properties known to influence performance in ICP-MS analysis such as plasma forward power, gas flows (nebulizer and auxiliary), torch injector internal diameter, and water load into the plasma were examined.Additionally, LODs and linear dynamic range for selected analytes were determined for MICAP-QMS with solution sample introduction.The instrument was optimized for maximum signal intensity while maintaining the oxide-to-element ratio (i.e.CeO + /Ce + ) at 3% and double charged ion formation (i.e.Ba ++ /Ba + ) at 2%.Changes in plasma forward power show no or little effect on ionization of low-ionization-energy elements; however, higher power is required for ionization of elements with first ionization energies greater than ~9 eV.The nebulizer and auxiliary gas flows of the MICAP were optimal at 1.15 and 1.50 L min -1 , respectively.A comparison of wet and dry (desolvated) sample introduction with injector diameters of 0.8, 1.5, and 2.4 mm showed that optimal conditions are obtained with a dry plasma and a 1.5 mm injector diameter.A linear dynamic range (LDR) of 10 8 for the MICAP-QMS is demonstrated; this LDR is 2-3 orders of magnitude lower than conventional ICP-QMS.The LDR of the MICAP-QMS is limited at low concentrations by a high continuous background, likely from metastable ions or photons reaching the detector.Limits of detection span from parts-per-trillion to parts-per-billion.