The purpose of this study was to identify a characteristic elemental tyre fingerprint that can be utilised in atmospheric source apportionment calculations. Currently zinc is widely used as a single element tracer to quantify tyre wear, however several authors have highlighted issues with this approach. To overcome this, tyre rubber tread was digested and has been analysed for 25 elements by ICP-MS to generate a multielement profile. Additionally, to estimate the percentage of the tyre made up of inert fillers, thermogravimetric analysis was performed on a subset. Comparisons were made between passenger car and heavy goods vehicle tyre composition, and a subset of tyres had both tread and sidewall sampled for further comparison. 19 of the 25 elements were detected in the analysis. The mean mass fraction of zinc detected was 11.17 g/kg, consistent with previous estimates of 1% of the tyre mass. Aluminium, iron, and magnesium were found to be the next most abundant elements. Only one source profile for tyre wear exists in both the US and EU air pollution species profile databases, highlighting the need for more recent data with better coverage of tyre makes and models. This study provides data on new tyres which are currently operating on-road in Europe and is therefore relevant for ongoing atmospheric studies assessing the levels of tyre wear particles in urban areas.

Accurate measurement of natural and anthropogenic radionuclide concentrations is of critical importance to end users in the nuclear sector to ensure correct classification prior to storage, recycling, reprocessing or disposal. Uncertainties in the characterisation of solid matrices and materials could lead to safety, quality and financial implications. Robust sample preparation methods are vital, in particular effective sample digestion, as under-estimated chemical yield recovery results in a corresponding under-estimation of activity levels. Borate fusion has been proven to effectively digest a range of complex sample matrices in the geosciences but is not used routinely elsewhere. In this study, we describe an automated procedure for borate fusion of multiple matrices encountered in nuclear decommissioning, containing diverse radionuclides over a range of activity concentrations. The impact of digestion flux, sample mass and sample to flux ratios are described, as well as the subsequent separation and measurement techniques. The results contribute to accurate and precise measurement of radionuclides in various matrices, as well as to characterisation of reference materials, providing greater confidence in nuclear industry programmes worldwide.

Highlights in the field of air analysis included: development of laboratory-based particle emission simulators to emulate real-world processes such as tyre-wear abrasion; ongoing performance verification of Hg calibrators; progress in laser and spark emission spectroscopic techniques for in situ aerosol measurements, advances in data processing software tools in supporting sp-ICP-MS measurements, feasibility of using aerosol mass spectrometers for measuring nanoplastics in air, and a comprehensive review of brown carbon aerosols, its sources, optical properties and measurement approaches used. While recent developments in water analysis include significant progress in sp-ICP-MS, including the introduction of new measurement protocols, determination of isotope ratios, and new reference materials. The number of studies employing LIBS for assessing metal burdens in water has also grown notably, particularly with respect to innovations in sample preparation. Advances were further reported in the development of portable analytical devices and systems for continuous environmental water monitoring. In addition, several comprehensive reviews were published, providing guidance for researchers on establishing robust measurement workflows, including split-stream and sp-ICP-MS methodologies. In the analysis of plants and soils, there has been increased interest in deep eutectic solvents as milder and greener alternatives to traditional extractants. Microwave plasma torch mass spectrometry methods have been developed that allowed concurrent measurement of trace elements and organic pollutants in liquid samples. Promising steps have also been taken towards application of techniques for direct analysis of solids. Advances in LIBS have largely focussed on data processing and modelling whilst in XRF, the influence of soil matrix composition on measurement accuracy was highlighted. Quantitative geochemical analysis faces continuous challenges, making the development of new RMs a persistent priority, especially for localized microanalysis. Application of LIBS is gaining increasing interest because of its portability and the use of machine learning tools to improve the quality of the obtained data. Interest is also increasing in the analysis of extraterrestrial samples. Novel ICP-MS instrumentation has offered highly precise isotopic analysis and spectral interference removal. Other important techniques in this review period have been nanoSIMS, NAA, and MS variants because they may provide new and enhanced chemical information. The fusion of data and the significantly increasing application of AI for rapid mineral identification and data integration marks a key trend that is expected to grow exponentially.

Non-exhaust emissions are becoming of increasing significance with respect to total particulate matter (PM) concentrations in ambient air. Of particular interest is the metal content of this PM since metallic compounds are well known to have toxic effects on human health and the environment. In this study, ‘bottom-up’ annual tyre wear emission rates were estimated and compared to top-down’ emissions declared by the UK; it was calculated that between 14 and 25 tonnes of Zn entered the atmosphere in PM₁₀ in 2020. The emission rates were estimated using a cost-effective, simple but robust validated method for analysis of the metals in tyres using tandem inductively coupled plasma mass spectrometry (ICP-MS/MS) for the first time, involving minimal offline sample preparation. This method was applied to five different tyre makes and brands, all available for sale in the UK, and the uncertainty of each measurement was determined. Traceability was ensured in all methods and novel validation techniques were applied due to lack of available reference materials. Zn was found to be the largest metal component in all tyres with a mass fraction of approximately 10 mg g⁻¹. The mean mass fractions of metals in the tyres decreased in the order of Zn > Al > Fe > Mg > Ti > Pb > Cu > Ba > Ni. Significant differences in composition were found between the five tyres. The relative expanded uncertainties of the metals measurements ranged from 4 to 21%, with elements of higher mass fraction resulting in lower uncertainties. These findings will contribute to assessing current and future air quality challenges and will help to inform regulation surrounding non-exhaust emissions.