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Stepping-up accurate quantification of chlorinated paraffins: Successful certification of the first matrix reference material

Ricci, Marina; Boer, Jacob de; Johansen, Jon Eigill; Huiling, Liu; Dumas, Pierre; Warner, Nicholas Alexander; Pērkons, Ingus; McGrath, Thomas Jacob; Borgen, Anders; Bjørneby, Stine Marie; Tomasko, Jakub; Steer, Helena; Lentjes, Anouk; Velzen, Martin van; Mourik, Louise van

Background
Chlorinated paraffins (CPs) are industrial chemicals categorised as persistent organic pollutants because of their toxicity, persistency and tendency to long-range transport, bioaccumulation and biomagnification. Despite having been the subject of environmental attention for decades, analytical methods for CPs still struggle reaching a sufficient degree of accuracy. Among the issues negatively impacting the quantification of CPs, the unavailability of well-characterised standards, both as pure substances and as matrix (certified) reference materials (CRMs), has played a major role. The focus of this study was to provide a matrix CRM as quality control tool to improve the comparability of CPs measurement results.

Results
We present the process of certification of ERM®-CE100, the first fish reference material assigned with certified values for the mass fraction of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively). The certification was performed in accordance with ISO 17034:2016 and ISO Guide 35:2017, with the value assignment step carried out via an intercomparison of laboratories of demonstrated competence in CPs analysis and applying procedures based on different analytical principles. After confirmation of the homogeneity and stability of the CRM, two certified values were assigned for SCCPs, depending on the calibrants used: 31 ± 9 μg kg−1 and 23 ± 7 μg kg−1. The MCCPs certified value was established as 44 ± 17 μg kg−1. All assigned values are relative to wet weight in the CRM that was produced as a fish paste to enhance similarity to routine biota samples.

Significance and novelty
The fish tissue ERM-CE100 is the first matrix CRM commercially available for the analysis of CPs, enabling analytical laboratories to improve the accuracy and the metrological traceability of their measurements. The certified CPs values are based on results obtained by both gas and liquid chromatography coupled with various mass spectrometric techniques, offering thus a broad validity to laboratories employing different analytical methods and equipment.

2024

Stochastic and deterministic processes in Asymmetric Tsetlin Machine

Elmisadr, Negar; Belaid, Mohamed-Bachir; Yazidi, Anis

This paper introduces a new approach to enhance the decision-making capabilities of the Tsetlin Machine (TM) through the Stochastic Point Location (SPL) algorithm and the Asymmetric Steps technique. We incorporate stochasticity and asymmetry into the TM's process, along with a decaying normal distribution function that improves adaptability as it converges toward zero over time. We present two methods: the Asymmetric Probabilistic Tsetlin (APT) Machine, influenced by random events, and the Asymmetric Tsetlin (AT) Machine, which transitions from probabilistic to deterministic states. We evaluate these methods against traditional machine learning algorithms and classical Tsetlin (CT) machines across various benchmark datasets. Both AT and APT demonstrate competitive performance, with the AT model notably excelling, especially in complex datasets.

2025

Storage and reporting of odd samples. NILU OR

Knudsen, S.; Narayansamy, M.

Rapporten gir anbefalinger om hvordan målekampanjer skal rapporteres og lagres og gir anbefalinger på hvordan systemet skal være for at den innsamlede informasjonen skal være tilgjengelig i ettertid. Det anbefales å opprette en relasjonsdatabase som fungerer som et bibliotek der sentral informasjon gjøres søkbar og det opprettes søkeord som klassifiserer dataene og rapportene.

2010

Store metanutslipp

Myhre, Cathrine Lund (intervjuobjekt); Molde, Eivind (journalist)

2020

Støtte til nye vedovner garanterer ikke for renere luft

Grythe, Henrik; Lopez-Aparicio, Susana (intervjuobjekter); Fossen, Erik (journalist)

2020

Støv – hva er det og hvordan måler vi det?

Weydahl, Torleif; Hak, Claudia

2023

Støv på hjernen - hvor kommer støvet fra/er det farlig?

Nipen, Maja (intervjuobjekt); Cederström, Madeleine (journalist)

2024

Støver ned

Solbakken, Christine Forsetlund (intervjuobjekt); Rapp, Ole Magnus (journalist)

2020

Støvfall fra mobilt knuseverk ved E18 i Østfold. 19.11.2015 - 20.06.2016. NILU rapport

Haugsbakk, I.

NILU har målt støvfall ved tre målestasjoner langs E18 i Østfold i forbindelse med steinknusing. Støvfallsnivået kan karakteriseres som lavt.

2016

Støvfallsmålinger ved Glasitt AS i Skjåk. 19.08.2010-31.08.2011. NILU OR

Haugsbakk, I.

NILU har målt støv omkring Glasitt AS sitt gjenvinningsanlegg for glass i Skjåk i perioden 19.08.2010 - 30.08.2011. Resultatene fra målingene viste overskridelse av retningslinje for støvfall ved alle tre målestasjoner.

2011

Støvfallsmålinger ved pukkverk i Sandnessjøen 28.06.2010 - 07.02.2011. NILU OR

Haugsbakk, I.

NILU har målt støv omkring Aquarock AS sitt pukkverk i Sandnessjøen i perioden 28.06.2010 - 07.02.2011. Resultatene fra målingene viste overskridelse av retningslinje for støvfall 600 m nordvest for virksomheten.

2011

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