Non-targeted liquid chromatography tandem high-resolution mass spectrometry (LC-MS/MS) is increasingly applied for the structure-resolved chemical analysis of dissolved organic matter (DOM). With new developments in MS instrumentation and analysis software, the approach has gained substantial momentum over the past decade. However, achieving high-quality analytical data that is reproducible and comparable across laboratories can be a bottleneck in non-targeted metabolomics and organic matter chemical analysis, especially for data reuse in repository-scale analyses. Understanding the capabilities as well as challenges of comparing LC-MS/MS data from different laboratories is necessary for inferring global trends from public data sets. To illuminate instrumentation factors that drive differences and variability, we used a standardized data analysis pipeline, including classical (CMN) and feature-based molecular networking (FBMN), to analyze data from a ring trial by 24 laboratories on identical sample sets of algal and DOM extracts that were mixed in predefined concentrations and spiked with standards. Our results showed that data sets from similar mass spectrometer types with unified instrument parameters were qualitatively comparable, resolving the same general trends and shared mass spectral features. Interlaboratory comparability was best for high-intensity features, while low-intensity features showed greater detection variability. Our analysis also highlights challenges when comparing data from instruments with different acquisition rates or operating with less standardized methods. Lastly, we provide recommendations for data integration, public data sharing, standardization, and best practices for standardized LC-MS/MS data acquisition, which will be critical for long-term time series and intercomparability of DOM chemical analyses.

Interactions between islands and mainland has long been the subject of numerous archaeological projects in the Mediterranean and beyond. The island of Kythera in Greece has been a focal point for such studies over the last century. This paper re-visits Kythera and presents an analytical study on pottery and skeletal assemblages from the Kataphygadi cave excavations in the central west Kythera, in order to further explore insular dynamics and long-range interactions in the area, during the Bronze Age. The range of analyses, from organic residue and petrography to archaeological isotopes, employed to identify the role of the cave and the island in the Bronze networks, can be a pilot study for similar research questions on the role of cave sites in insular environments. Outcomes present a more diverse picture of interactions and regional dynamics than previously thought, with local traditions surviving long into the later Bronze Age and amalgamating with practices and material culture arriving from both the mainland and Crete.

While animal fats are by far the most widespread class of lipid residue preserved in archaeological potsherds, the possibility of mixing foodstuffs in vessels is evident from the detection of plant lipid residues in some sherds. Such 'mixed' extracts are usually treated cautiously when determining the origins of the animal fat components. This is particularly relevant in regions where broomcorn millet (Panicum miliaceum) was introduced by pioneer farmers alongside domesticated animals. Broomcorn millet processing has been identified in lipid extracts of archaeological potsherds based on the detection of miliacin, typically accompanied by abundant animal fats. Degradation experiments have been conducted to explain the abundance of miliacin observed in archaeological lipid extracts. We now explore the effects of processing varying proportions of millet grains with animal products on the delta 13C values of C16:0 and C18:0 fatty acids used to assign the origins of animal fats. A combination of theoretical mixing calculations and laboratory experiments were used to test different scenarios of mixing animal products and millet grains in archaeological pottery vessels. In all instances the millet fatty acids were found to be isotopically 'invisible' when processed with meat or dairy products due to 'overprinting' by the abundant animal acyl lipids and the low extraction efficiency of water for millet lipids. Thus, the delta 13C values of C16:0 and C18:0 fatty acids can be used confidently to determine the origins of animal fats even when millet processing is detectable through the miliacin biomarker.

The distinctive musty odour of Egyptian mummies is evident to anyone who has encountered their tissues and balms. A reasonable assumption is that this odour is the product of the decay of the mummy body tissues combined with volatile compounds released from aged balms and bandages. Given the established complexities and variabilities in the compositions of mummy balms, it is expected that variations in balm compositions will be reflected in the chemical compositions of the odour. Herein, we explore the chemical compositions of the volatile organic compounds (VOCs) constituting the odours of a range of balms and tissues of ancient Egyptian mummies then relate the differences in VOC composition to the known composition of embalming materials. Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography/quadruple time-of-flight mass spectrometer (GC/Q-TOFMS), provides a minimally invasive analytical approach to the characterisation of the volatile fraction of ancient Egyptian mummies. The VOC profiles of the embalming agents identify VOCs representative of each embalming substance, for example: aromatic compounds and short-chain fatty acids from fat/oil; mono-carboxylic fatty acids and cinnamic compounds from beeswax; aromatic compounds and sesquiterpenoids from resins, and naphthenic compounds from bitumen. The differences in composition previously determined between balms when correlated with VOC profiles indicates that VOCs can be used as a fast and sensitive screening tool to indicate the composition of ancient embalming substances.

Proteins have been used as adhesives in art throughout history, but determining their source in aged paintings is challenging. Moreover, the distinction between terrestrial and aquatic animal glues is only achievable with proteomic approaches. Compound-specific isotope analysis (CSIA) of collagen, used in the neighboring field of archeology for analogous purposes, has so far required too much sample to be used for painted objects. However, this paper presents a methodology that enables a reduction of sample size by about 3 orders of magnitude (from mg to μg), widening the application of CSIA to rare and fragile objects in our cultural patrimony. Based on direct inlet pyrolysis-gas chromatography-combustion-isotope ratio mass spectrometry (DIP-GC-C-IRMS), the method targets the δ13C values of pyrolytic protein markers, especially diketopiperazines (DKPs), reported here for the first time. The isotopic imprint of modern references for rabbit skin and isinglass glues, casein, and chicken and duck eggs was confirmed through established elemental analysis (EA)-IRMS and GC-C-IRMS methods. As expected, bulk and individual amino acid (AA) δ13C and δ15N values for terrestrial animal glues exhibited a higher depletion than those for marine glues, a relationship retained by the DKP δ13C values. Furthermore, the ground layers of two 16th-century Italian paintings from the National Gallery collection yielded δ13CDKP values consistent with terrestrial animal glue, confirming that the isotopic signature of these compounds is retained during aging and degradation.

Agricultural plastic film mulch (PFM) covers ca. 50 million hectares of the Earth's surface and has revolutionized agriculture, particularly in arid and semi-arid regions, by improving crop yields, water use efficiency, farmer incomes and feeding an extra 85 million people in China alone. However, concerns are growing about the impact of PFM-derived microplastics (MP) on soil quality, the food chain, and the environment. Here we show that current research on the effects of MP in agricultural soils is limited by inconsistent methodologies and unrealistic experimental concentrations, leading to major uncertainty in assessing the true risks associated with PFM use. Furthermore, we highlight the need for standardized protocols, experiments using realistic MP concentrations, and a better understanding of the relative contribution of PFM to MP pollution to develop informed policies. Furthermore, while biodegradable alternatives show promise, their significantly higher costs (2-3 times that of conventional LDPE PFM) and variable performance across different agricultural environments present economic and practical challenges that must be addressed through targeted policy incentives and continued technological innovation. Our findings suggest that while further research is conducted, managing PFM to reduce environmental impact, rather than imposing ill-informed bans on plastic use, is crucial to balance food security and sustainable development goals. Exploring "zero-leakage" instead of "zero-use" approaches to PFM should be the primary aim to help mitigate potential risks while preserving the substantial benefits of this agricultural technology.

Biodegradable polyester mulch films are a viable alternative for use in agriculture to polyolefin-based films, offering reduced long-term microplastic pollution in agroecosytems with comparable protections for food security. However, these films carry diverse organic additives and non-intentionally added substances (NIASs), representing an underexplored source of anthropogenic chemicals in agroecosystems. Comprehensive chemical characterisation of these films is critical but hindered by restrictions on revealing proprietary formulations. This study presents a non-targeted screening (NTS) workflow employing multiple complementary analytical techniques to elucidate the organic composition of a polylactic acid (PLA)/polybutylene adipate-co-terephthalate (PBAT) mulch film. 1H nuclear magnetic resonance (NMR) quantified polyester contributions to the blend and revealed an unreported polybutylene sebacate (PBSe) component, likely from polybutylene sebacate terephthalate (PBSeT). Dissolution-precipitation extraction of the film followed by gas chromatography-mass spectrometry (GC-MS) and GC-flame ionisation detection (GC-FID) identified key additives in the extracted soluble fraction, including acetyl tributyl citrate (ATBC) plasticiser (4210 ± 135 μg g-1), and 8 cyclic oligoesters up to dimers. High-performance liquid chromatography-Orbitrap-mass spectrometry (HPLC-Orbitrap-MS) and direct infusion (DI)-Orbitrap-MS expanded oligoester detection to 83 additional components beyond the analytical window of GC-MS. The detailed oligoester profiles underscore the need to apply this workflow to biodegradable mulch films from diverse commercial sources and food industry applications to assess their broader chemical variability. These methodologies offer critical tools for the life cycle assessment of biodegradable agricultural plastic mulch films, advancing our understanding of the environmental impact and safety of these new materials.

During the first millennium AD, the much-discussed Migration Period marked a major episode of demographic and consequent economic, social and political change across large areas of Europe. Slavic migration from Eastern into Central Europe, between 500 and 700 AD, brings a proposed change in ‘kitchen culture’ and subsistence, displacing Germanic (e.g. Longobard) groups elsewhere, marking the end of the Late Antique period and the beginning of the Middle Ages. Notably, organic residue analysis of a total of 75 vessels from across the span of these periods confirms a distinct dietary shift between these purported groups. Food can often be one of the most distinctive expressions of social, religious, cultural or ethnic groups and, here, we demonstrate that a clear reliance on millet, in the form of porridge made with milk and, possibly, honey or soups and stews with meat, dominates, likely brought from the Slavic homelands. Thus, absent in the late Antique period, a new diet based on millet may thus have been a contributing factor to the population increase during the Early Medieval period and the subsequent expansion by Slavic groups across Europe. Analysis of a large series of legacy radiocarbon dates from human and animal bone, supported by compound-specific lipid dating of four of the same vessels allows us to identify the turning point of the change in habitus, with Slavic-speaking communities with a new housing culture, foodways and burial rites appearing in Moravia (Czech Republic) and Lower Austria, by the latest 598 AD (but probably much earlier, between 560 and 590 AD).

Correction for ‘Microbial degradation of bioplastic (PHBV) is limited by nutrient availability at high microplastic loadings’ by Michaela K. Reay et al., Environ. Sci.: Adv., 2025, 4, 133–146, https://doi.org/10.1039/D4VA00311J.

Plastic additives associated with plastic products are essential to their function. However, a number of compounds, which are included at relatively high abundances, and frequency in plastic products, have known associated hazards. These include phthalates, which are endocrine disruptors, as well as antioxidants and UV stabilisers, which may bioaccumulate. As additives are not chemically bound, they are susceptible to leaching to the wider environment, including into soils. However, the potential abiotic controls on degradation of additives in soil, such as soil type, pH and nutrient availability, following leaching remains unknown. This study investigates the degradation of three contrasting, high production plastic additives in soil to elucidate potential controls on the bioavailability of the plastic additives. Three additives of contrasting function were selected: bis(2-ethylhexyl) phthalate (DEHP), a plasticiser, which is an endocrine disruptor; tris(2,4-di-tert-butylphenyl)phosphite (Irgafos® 168, an antioxidant under assessment as bio accumulative under EU REACH, and octabenzone, a UV stabiliser. An agricultural soil from North Wales with no previous history of plastic use was sieved (2 mm) and maintained at constant moisture (30% WHC). Additives were dried onto sand then homogenised in soil to yield a concentration of 500 ng g−1 soil. The degradation of additives was monitored over a 21 d time course with light exclusion. In the UK soil, Irgafos® 168 was not detected after t=0 d, due to rapid conversion to its oxidation product, tris(2,4-di-tert-butylphenyl)phosphate (Irgafos® 168ox), which also occurs abiotically during plastic production. However, no further microbial degradation of this antioxidant was observed over the 21 d period. DEHP and octabenzone both exhibited rapid degradation within 4 d, yet remained at 223 ng g−1 and 51 ng g−1, respectively, for the remainder of the 21 d experiment. The degradation of DEHP and octabenzone is proposed to be microbial, with 49% and 78% removed over 21 d, and the relative bioavailability of the additives was octabenzone>DEHP>>Irgafos® 168(ox). This will be expanded to include soils from across climatic zones (India, Vietnam, Australia, Brazil, Egypt), to elucidate controls on additive degradation linked to soil properties, including pH, soil type and nutrient availability, which are hypothesised to influence the bioavailability and preference for additive degradation.

Plastic mulch films support global food security, however, their composition and the potential release rates of organic, metal and metalloid co-contaminants remains relatively unknown. This study evaluates the low molecular weight organic additives, metal and metalloid content and leaching from low density polyethylene (LDPE) and biodegradable plastic mulch films. We identified 59 organic additives, and non-intentionally added substances in the new LDPE films (39.8 mg m- 2) and 60 in the new biodegradable films (129 mg m- 2). The leaching of organic compounds of high concern for ecosystem and human health (e.g. phthalates, organophosphite antioxidants) was comparable to those of low concern (fatty acids, fatty amides, alkanols). However, the majority of leached compounds have undergone no regulatory scrutiny and their environmental fate and toxicity remain unknown. Leaching of heavy metals (Cu, Zn, Pb) was low relative to inert fillers (Ca, Na). Leaching was higher for both organic and metal/metalloid additives from the biodegradable films (74.6 mg m- 2) than the LDPE films (23.7 mg m- 2). This untargeted approach allowed assessment of the chemical burden posed to individual farms, based on existing use patterns of plastic mulch films, with higher chemical burden coming from biodegradable films, raising the potential for pollution swapping. This research emphasises the need to include the complex mixture of leached additives when assessing the environmental risks presented by plastic mulch films, balancing yield benefits with the protection of our agricultural soils.

Archaeological excavations conducted in 2017 at Grantown Road, Forres form the final phase of works on a residential development that began in 2002. The earlier works examined an area of more than 70ha and confirmed the presence of an extensive Iron Age settlement represented by ring-ditch, ring-groove, and post-ring structures, in association with four-post structures, a souterrain, and metalworking furnaces. The 2017 works (Canmore ID 320363), reported here, have expanded the record of prehistoric and medieval settlement in the area and revealed that a previously recorded cropmark site represented an Iron Age enclosure with a single post-ring roundhouse. Also identified in the present works were an Early Neolithic post-ring structure and a series of pits dating from the Neolithic to the medieval periods with artefact assemblages of pottery, lithics, and stone tools, including a rare fragment of a locally made mortar dated to the 13th century ad.

Archaeological excavations conducted in 2017 at Grantown Road, Forres form the final phase of works on a residential development that began in 2002. The earlier works examined an area of more than 70ha and confirmed the presence of an extensive Iron Age settlement represented by ring-ditch, ring-groove, and post-ring structures, in association with four-post structures, a souterrain, and metalworking furnaces. The 2017 works (Canmore ID 320363), reported here, have expanded the record of prehistoric and medieval settlement in the area and revealed that a previously recorded cropmark site represented an Iron Age enclosure with a single post-ring roundhouse. Also identified in the present works were an Early Neolithic post-ring structure and a series of pits dating from the Neolithic to the medieval periods with artefact assemblages of pottery, lithics, and stone tools, including a rare fragment of a locally made mortar dated to the 13th century ad.

Dissolved organic matter (DOM) plays a vital role in river ecosystem function and therefore understanding its composition is key. DOM has important implications for nutrient cycling and riverine health and with this in mind, it is vital to gain a more comprehensive understanding of the composition of riverine DOM at a molecular level and how this varies across contrasting landscapes. There are many factors which will influence DOM signatures, from differences in climate, soil type/geology, land-use, as well as intensity and nature of anthropogenic activity. Through understanding the potential relationships between these factors and DOM composition, we can gain key information regarding both sources of riverine DOM within river catchments, aiding pollution mitigation strategies, and how signatures may vary under changing climate and/or land-use. The analysis of DOM poses a significant analytical challenge due to its complexity, however the advances in mass spectrometry now allows detailed characterisation at molecular scale. This study examines the DOM composition across 56 UK field sites spanning contrasting landscapes, including four different geologies/soil types. Additionally, 18 effluents from UK sewage treatment works (STW) were investigated. River water samples were collected and an untargeted analysis carried out using direct-infusion high-resolution mass spectrometry (DI-MS) and the resultant DOM signatures across the samples were compared. Principal component analysis (PCA) and hierarchical clustering analysis methodologies were applied and showed that the DOM molecular composition between sites could be distinguished according to landscape character. Specifically, the PCA analysis showed that contrasting geologies/soil types were separated by the derived Principle Component (PC) 2 while PC1 separated the riverine samples from the STW effluents in the analytical space. Explanatory variables including landcover, land-use and population density alongside bulk nutrient data were used to begin to elucidate the driving factors behind the PCs. In addition to differences in DOM signatures, further analysis of the molecular compositions identified anthropogenically derived organic compounds, for example, series of polypropylene glycol (PPG) and polyethylene glycol (PEG) oligomers, which were present in almost all landscapes across the UK, illustrating that they are now ubiquitous across riverine environments. Using these data, we can begin to provide generalisable information regarding the molecular composition of DOM across different UK landscapes.

Biodegradable plastic offers an alternative to conventional plastic for use in agriculture. However, slower degradation in the environment compared to industrial composting and high production of microplastics is of growing concern and poses the question whether they represent a viable replacement. It remains unclear whether observed effects of biodegradable plastics on the soil microbial community and plant nutrient uptake are from biodegradation or from the abiotic effects of the microplastics themselves. The aim of this study was to quantify the biodegradation of the bioplastic poly beta-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), at increasing microplastic loadings (0.06-3.2% w/w) via pyrolysis/gas chromatography-mass spectrometry (Py/GC-MS) alongside effects on soil health and plant growth (Zea mays L.). Between 1.5 and 5% of PHBV microplastic was degraded in soil after 8 weeks, with the rate declining with increasing PHBV concentrations due to microbial nitrogen (N) limitation, demonstrated by increased investment in N-cycling enzymes. Plants were also limited by both N and phosphorus (P). Greater extractable soil ammonium and nitrate contradicted N limitation, however, increases in soil hydrophobicity likely limited mobility, and thus plant and microbial utilisation. As a result, increased C from PHBV degradation did not result in a concurrent increase in microbial biomass, which was reduced under higher PHBV microplastic loading, indicating low microbial carbon use efficiency. While high PHBV microplastic loadings resulted in significant effects on the microbial community size and structure, soil properties and plant growth, there were minimal effects at low PHBV concentrations (0.06% w/w). Observations of nutrient limitation at higher plastic loadings has significant implications for the design of standard biodegradation assays, which must consider both abiotic and biotic effects of microplastic on soil nutrient cycling.

The local adaption of soil microbial communities to native litter inputs, the so-called home field effect (HFE), is well established, though this phenomenon has yet to be demonstrated for agriculturally relevant inorganic nutrient sources. Using compound-specific N-15-stable isotope probing of proteinaceous amino acids (AAs), we investigated if continuous long-term grassland fertilisation with either ammonium or nitrate resulted in preferential assimilation by the soil microbial community of the 'home' N fertiliser. Relative ammonium uptake was maximal in historic ammonium treated soils and previously unfertilised soil, confirming a general microbial preference for ammonium likely due to biochemical transformation efficiencies. Assimilation of nitrate and ammonium into AAs was comparable for the historic nitrate fertilisation, indicating that microbial adaptive processes governed by historical land use can dictate the immobilisation efficiency of different fertilisers. This is the first observation of the HFE in long-term fertilised grassland soils, with further work required to investigate abiotic or biotic mechanisms underpinning this phenomena.

Accessory vessels, including platters, dishes, beakers, flagons, jars, and amphorae, are a common feature of Romano-British burials, raising questions as to their provenance; for example, were such vessels recycled from the domestic sphere or made specially for funerary purposes? Furthermore, uncertainty surrounds their purpose: did they contain foods for the deceased, possibly for their final journey to the underworld? Interestingly, organic residue analysis of vessels from Baginton, a site adjacent to The Lunt fort, Coventry, an early (mid to late first century) Roman military cremation cemetery did not yield evidence for food offerings and may have reflected the use of seconds or damaged vessels in burials, perhaps to provide a symbolic meal. In contrast, here we provide, for the first time, direct chemical and isotopic evidence for ‘meals for the dead’, comprising mainly dairy products, often mixed with leafy plants, extracted from somewhat unusual accessory vessels found in a small, enclosed inhumation cemetery, perhaps associated with a family group, which dates to the late (third to late fourth century, or early fifth century A.D) in urban Canterbury. Thus, we can confirm that accessory vessels found in later Romano-British burials were, in this instance, used in the laying out of funerary meals, presumably to nourish the soul on the journey to the underworld. These preliminary insights on vessel use and burial practices across the span of the Roman occupation of Britain thus provide a strong hint at the diversity of Roman burial practices.

Esh-Shaheinab is a landmark in the African Neolithic. This site gave the name Shaheinab Neolithic to the Neolithic period in central Sudan, becoming its archetype. Excavated in the late 1940s by A.J. Arkell, it bears witness to the processes of domestic animal introduction from the Middle East into North and East Africa. Its excavation also uncovered the remains of an earlier Mesolithic or Early Khartoum (ca. ninth-sixth millennia BC) and a Late Neolithic occupation (ca. fourth millennium BC), providing essential insights into the Neolithic’s premises and sequels. Although the influence of Esh-Shaheinab has been recognized for more than seventy years, our knowledge of its material culture has remained as it was then. In 2001, one of the present authors (EAAG) had permission to restudy the ceramic collection at the National Museum in Khartoum and subsequently export samples for laboratory analyses. Here, for the first time, we provide a multi-scale analysis of the Esh-Shaheinab ceramic material from the Early Khartoum to the Late Neolithic periods by integrating the chaîne opératoire approach into the local landscape. By combining the results of macroscopic and microscopic analyses, we performed petrographic investigations on the composition and manufacturing technology of the ceramic pastes using polarized optical microscopy (POM) and scanning electron microscopy (SEM-EDS). Organic residue analysis (ORA) was also carried out, to provide information on diet, vessel use, and subsistence practices. The results of our combined analyses showed that the inhabitants of Esh-Shaheinab developed an adaptation specific to the ecological niche they inhabited. They lived in the western valley of the Nile, which was narrower and offered different environmental conditions than the eastern bank. This resulted in partial continuity in manufacturing traditions and ceramic recipes, including more mixed wadi materials and a strong emphasis on wild meat consumption as the narrower alluvial plain restricted animal herding.