| 1. |
- Ahrens, Lutz
(författare)
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Harmonized quality assurance/quality control provisions to assess completeness and robustness of MS1 data preprocessing for LC-HRMS-based suspect screening and non-targeted analysis
- 2024
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Ingår i: Trends in Analytical Chemistry. - 0165-9936. ; 174
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Forskningsöversikt (refereegranskat)abstract
- Non-targeted and suspect screening analysis using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) holds great promise to comprehensively characterize complex chemical mixtures. Data preprocessing is a crucial part of the process, however, some limitations are observed: (i) peak-picking and feature extraction might be incomplete, especially for low abundant compounds, and (ii) limited reproducibility has been observed between laboratories and software for detected features and their relative quantification. We first conducted a critical review of existing solutions that could improve the reproducibility of preprocessing for LC-HRMS. Solutions include providing repositories and reporting guidelines, open and modular processing workflows, public benchmark datasets, tools to optimize the data preprocessing and to filter out false positive detections. We then propose harmonized quality assurance/quality control guidelines that would allow to assess the sensitivity of feature detection, reproducibility, integration accuracy, precision, accuracy, and consistency of data preprocessing for human biomonitoring, food and environmental communities.
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| 2. |
- Andersson, Anna, et al.
(författare)
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Extending the potential of Fourier transform ion cyclotron resonance massspectrometry for the analysis of disinfection by-products
- 2023
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Ingår i: TrAC. Trends in analytical chemistry. - : ELSEVIER SCI LTD. - 0165-9936 .- 1879-3142. ; 167
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Forskningsöversikt (refereegranskat)abstract
- Potentially harmful disinfection by-products (DBPs) are formed upon drinking water treatment when disinfectantsreact with organic matter in the water. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) provides information on the compositions of individual DBPs in the unknown, toxicologically relevantfraction, comprising non-volatile, high-molecular weight DBPs. This review evaluates current applications of FTICR-MS for DBP analysis to assist improved analysis with this technique. Four methodological aspects are infocus, 1) The use of quenching agents, 2) The choice of extraction method 3) The choice of ionization techniques/modes, and 4) Data processing including DBP formula verification and interpretation. Quenching can lead todecomposition or adduct formation and needs to be further evaluated or avoided. There is a large potential toexpand FT-ICR-MS DBP analysis by applying different SPE sorbents and ionization techniques, and improvedsystematic verification procedures are important to ensure reliable non-target analysis.
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| 3. |
- Fernandes, Alwyn R., et al.
(författare)
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Recommended terms and abbreviations for polychlorinated alkanes (PCAs) as the predominant component of chlorinated paraffins (CPs)
- 2023
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier. - 0165-9936 .- 1879-3142. ; 169
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Forskningsöversikt (refereegranskat)abstract
- Despite several decades of study, ambiguities persist in terms used to express environmental and biotic occurrences of polychlorinated alkanes (PCAs), the main ingredient of chlorinated paraffins (CPs). This can lead to misinterpretation of data between analytical chemists, toxicologists, risk assessors/managers and regulators. The terms recommended here to harmonise reporting and reduce ambiguity use the conventional definition of PCAs - linear chlorinated alkanes (typically, C≥10) with one chlorine per carbon, although some evidence of multiple chlorination exists. Other recommendations include.● reporting the “Sum of measured PCAs” because “Total PCAs” is currently unquantifiable.●reporting individual chain lengths, e.g., ΣPCAs-C11, ΣPCAs-C13, allows easier comparability and allows toxicology and risk assessment to consider different PCA combinations.● maintain studies on individual PCAs in order to better characterise chemical, environmental and health risk behaviour.The terms could be extended in future to assimilate new findings on individual PCAs, multiple chlorination and chirality.
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| 4. |
- Fiedler, H., Dr. 1953-, et al.
(författare)
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Global interlaboratory assessments of perfluoroalkyl substances under the Stockholm Convention on persistent organic pollutants
- 2020
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier. - 0165-9936 .- 1879-3142. ; 124
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Tidskriftsartikel (refereegranskat)abstract
- The Global Monitoring Plan (GMP) according to article 16 of the Stockholm Convention on Persistent Organic Pollutants (POPs) requires that POP laboratories must be capable – at any time – to analyse samples for POPs within a variation of ±25%. Based on this target error of 25%, a statistical model using z-scores was applied to assess the performance of analytical laboratories for POPs and a number of matrices. Since the second round of these ‘Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants (POPs)’, carried out in 2012/2013, perfluoroalkyl substances (PFASs) have been included into the proficiency tests. The third round was carried out in 2016/2017. The test materials included test solutions of PFASs analytical standards, the abiotic matrices sediment, air (extract) and water and the biotic matrices fish, human milk and human plasma. The number of laboratories submitting results for PFASs remained quite stable (IL2 = 27 laboratories; IL3 = 29), but there was broader geographic distribution observed in IL3: in addition to the laboratories from Asia and the Western Europe/other groups, two laboratories from Africa participated, two from Central-Eastern Europe and one from the Latin American/Caribbean region.Considering that PFASs were introduced for the first time in round 2, the results were good to reasonable compared to those of a number of other POPs included in the same study. However, it shall also be mentioned that for some matrices and PFASs, the number of laboratories submitting results was too small and the results too scattered to derive a consensus value. This was especially true for the PFOS precursor compounds and the air matrix. Also, laboratories struggle with the analysis of the branched PFOS isomers.These interlaboratory assessments on PFASs gave promising results and demonstrated the importance of proficiency tests in an international environment to generate trust in laboratory results. The need to participate regularly in such intercomparison assessments is highlighted. The results show the current level of PFAS analysis, which varies by laboratory and by matrix rather than per geographic region.
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| 5. |
- Fiedler, Heidelore, Dr. 1953-, et al.
(författare)
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Persistent organic pollutants in air across the globe using a comparative passive air sampling method
- 2024
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier. - 0165-9936 .- 1879-3142. ; 171
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Tidskriftsartikel (refereegranskat)abstract
- For the global monitoring plan (GMP) established under the Stockholm Convention on Persistent Organic Pollutants (POPs), passive air samplers (PAS) equipped with polyurethane foam disks (PUFs) were recommended for generating comparative results on the presence of POPs in countries. One representative sampling location was designed in each of the 42 countries and the PAS/PUFs exposed for three months to collect POPs during 2017–2019. The PUFs were analyzed in three laboratories according to their chemical nature and concentrations reported per PUF and 90 ± 3 days of exposure. In total, 381 PUFs were analyzed for organochlorine pesticides (OCPs), industrial chlorinated POPs, dioxin-like POPs (dl-POPs), brominated flame retardants (BFRs), and perfluoroalkane substances (PFAS). Concentrations typically varied by a factor of up to three for a POP and often within the same geographic region or other denominator such as similar latitudes or altitudes. Maximum values were found for DDT (895 ng/PUF) in Africa, but the highest medium value was in the Latin American countries. Also, polychlorinated biphenyls (PCB) and hexachlorobenzene (HCB) were most abundant across all parameters assessed. Noteworthy were high values in single countries, such as DDT in the Solomon Islands, toxaphene in Mexico, β-HCH and lindane in Tanzania, hexachlorobutadiene and hexabromocyclododecone in Mongolia, deca-BDE and PFOS in Zambia. Although we had two sampling locations at very high altitudes, >2000 m, we could determine increasing POPs concentrations with increasing altitudes only for HCB but not for other POPs. A general dependency on latitudes with higher concentrations towards the north and south pole could not be found, although the most northern station in Mongolia had two of the maxima and elevated values for some legacy POPs.
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| 6. |
- Fornstedt, Torgny, 1957-, et al.
(författare)
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Method transfer in SFC from a fundamental perspective
- 2022
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier. - 0165-9936 .- 1879-3142. ; 149
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Tidskriftsartikel (refereegranskat)abstract
- The fundamental aspects to be considered during method transfer in supercritical fluid chromatography (SFC) are reviewed. The review is limited to mobile phases, stationary phases, and operating conditions generally encountered in current practice. First, the fundamentals of retention in SFC will be explored in relation to fluid composition, co-solvent adsorption to the stationary phase, pressure, and temperature. Second, considerations regarding predictable method transfer will be discussed in relation to instrumentation, columns, retention shifts, and method robustness. This review is not intended to be comprehensive but rather to highlight important issues for understanding and performing reliable method transfer and to give practical guidelines relating to the fundamentals covered.
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| 7. |
- Garcia-Guzman, Juan Jose, et al.
(författare)
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Microneedle based electrochemical (Bio)Sensing : Towards decentralized and continuous health status monitoring
- 2021
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier BV. - 0165-9936 .- 1879-3142. ; 135
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Forskningsöversikt (refereegranskat)abstract
- Microneedle (MN) based electrochemical (bio)sensing has become a growing field within the discipline of analytical chemistry as a result of its unique capacity for continuous, decentralized health status monitoring. There are two significant advantages to this exclusive feature: i) the ability to directly analyze interstitial fluid (ISF), a body fluid with a similar enough composition to plasma (and blood) to be considered a plentiful source of information related to biologically relevant molecules and biomarkers; and ii) the capacity to overcome some of the major limitations of blood analysis including painful extraction, high interferant concentrations, and incompatibility with diagnosis of infants (and especially newborns). Recent publications have demonstrated important advancements in electrochemical MN sensor technology, among which are included new MN fabrication methods and various modification strategies, providing different architectures and allowing for the integration of electronics. This versatility highlights the undeniable need for interdisciplinary efforts towards tangible progress in the field. In a context evidently dominated by glucose sensing, which is slowly being expanded towards other analytes, the following crucial questions arise: to what extent are electrochemical MN (bio)sensors a reliable analytical tool for continuous ISF monitoring? Which is the best calibration protocol to be followed for in vivo assays? Which strategies can be employed to protect the sensing element during skin penetration? Is there an appropriate validation methodology to assess the accuracy of electrochemical MN (bio)sensors? How significant is the distinction between successful achievements in the laboratory and the real commercial feasibility of products? This paper aims to reflect on those previous questions while reviewing the progress of electrochemical MN (bio)sensors in the last decade with a focus on the analytical aspects. Overall, we describe the current state of electrochemical MN (bio)sensors, the benefits and challenges associated to ISF monitoring, as well as key features (and bottlenecks) regarding its implementation for in vivo assays.
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| 8. |
- Garg, Mayank, et al.
(författare)
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Microfluidic (bio)-sensors based on 2-D layered materials
- 2023
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier BV. - 0165-9936 .- 1879-3142. ; 158
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Forskningsöversikt (refereegranskat)abstract
- Microfluidics has brought about tremendous advancements in measurement science, enabling low sample consumption, fast readout due to short diffusion distances and high throughput; the small footprint allows for multiplexing of chemical and biosensing. These features have been further enhanced by the incorporation of nanomaterials into microfluidic systems, in particular for electrochemical analysis systems. Much of the research regarding the use of 2-D materials for microfluidic biosensors has been dedicated to graphene nanostructures (graphene oxide, reduced graphene oxide and graphene quantum dots), less attention has been given to other graphene analogues. The aim of this review is to highlight the scientific advancements in analytical chemistry applications related to a wider range of 2-D materials such as 2-D Oxides, graphene analogues, 2-D chalcogenides and MXenes. The review focusses particularly on microfluidic electrochemical and optical sensors. (c) 2022 Elsevier B.V. All rights reserved.
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| 9. |
- Garg, Mayank, et al.
(författare)
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Strategies to remove templates from molecularly imprinted polymer (MIP) for biosensors
- 2024
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Ingår i: TrAC. Trends in analytical chemistry. - 0165-9936 .- 1879-3142. ; 170
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Forskningsöversikt (refereegranskat)abstract
- Molecularly imprinted polymers (MIP) have been of significant interest, especially for usage as recognition elements in biosensors. The sensitivity of a biosensor is largely governed by the interactions between the analyte and the recognition element. This represents a challenge for molecularly imprinted polymers as the interaction with the analyte relies on the successful creation of a template imprint. A crucial part of the process is the removal strategy of the template from the surrounding polymeric network. Since the inception of the field, there have been many strategies for this removal process, and these are the topic of this review. The focus is on template removal strategies from MIPs utilized for diagnostic biosensors. The literature survey of various strategies can be summarized into chemical-based and electrochemical-based template extraction. Generally, for chemical extraction solvents and acids are employed, whereas for electrochemical extraction, cyclic voltammetry is commonly used. These approaches are summarized and evaluated in the current review to provide guidance to researchers working in the areas of analytical chemistry, diagnostics, and materials science to better design MIP-based sensors.
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| 10. |
- Heinze, Wiebke Mareile
(författare)
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Fate of microplastics in sewage sludge and in agricultural soils
- 2023
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Ingår i: Trends in Analytical Chemistry. - 0165-9936. ; 166
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Forskningsöversikt (refereegranskat)abstract
- The aim of this study was to review microplastics (MPs) occurrence in sewage sludge from wastewater treatment plants (WWTPs) and assess implications of sludge application to agricultural soils. Sludge is a main sink for MPs in WWTPs, highlighting the importance of sludge as a route for environmental exposure. Sludge application on agricultural fields is associated with elevated MP concentrations in soils, potentially affecting soil health. However, prior to application sludge treatments may alter MP abundance and MPs properties, such as shape and size, subsequently affecting environmental risk. Knowledge gaps still exist regarding sludge treatments and their effect on MPs (size, shape abundance). Further investigation is needed to assess the risk of MPs exposure at WWTPs, explore the effects of sludge treatments on soil health, and to better understand how management at WWTPs, and in agricultural systems, affect MP properties. & COPY; 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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