Publications by authors named "Christoph von Holst"

Article Synopsis
  • - Combating antimicrobial resistance is a global priority that involves coordinated efforts from various health organizations and campaigns targeting different stakeholders like health professionals, the agricultural industry, and the general public.
  • - The Regulation (EU) 2019/4 aims to limit the contamination of animal feed with specific antimicrobials, highlighting the need for effective detection methods for antibiotics in feed.
  • - A new method was developed and validated for accurately detecting aminoglycoside antibiotics and spectinomycin in animal feed, showing high recovery rates and precision, which can help enhance regulatory control of antibiotic residues.
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The determination of urea in pet feed at contaminant levels using the spectrophotometric method described in Commission Regulation (EC) No 152/2009 has been reported by several EU laboratories to lack the required selectivity. Whilst urea is not authorised as an additive in pet feed, the control of urea in pet feed is of economic importance, because the addition of urea may unlawfully increase the apparent protein content. To investigate the capabilities of different analytical techniques, a proficiency test was organised where the participants (EU official control laboratories, laboratories from the academia and private laboratories) were free to use their method of choice for analysing three dog feed test materials, two samples of which were spiked with urea.

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The present work reports on the design, execution and evaluation of results of an interlaboratory validation study aimed at verifying the fitness-for-purpose of a LC-MS/MS method for the detection of polar pesticides in food of animal origin in official control and monitoring programmes. To this scope, five participant laboratories, with relevant expertise, were recruited. After passing a pre-trial test, the participants were asked to analyse test samples of bovine fat, chicken eggs and cow's milk, contaminated with 11 polar pesticides (group A: Aminomethyl phosphonic acid (AMPA), cyanuric acid, ethephon, glyphosate, fosetyl aluminium, 2-hydroxyethyphosphonic acid (HEPA), maleic hydrazide, N-acetyl-glyphosate, group B: N-acetyl glufosinate (NAG), 3-methylphosphinicopropionic acid (MPP) and glufosinate ammonium) at two different levels (0.

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In this study, direct analysis in real time high resolution mass spectrometry (DART-HRMS) was used to investigate the accurate characterisation of feed additive formulations containing coccidiostats or carotenoids. The study demonstrates the efficacy of DART-HRMS in identifying the active substances in these formulations and distinguishing between feed additives with the same active substance. The protocol for this method involves two simple steps that are extracting samples with organic solvents and measuring the extracts with DART-HRMS.

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Article Synopsis
  • Selenium (Se) is a crucial micronutrient for animal and human health, and the review explores its significance in the environment, plants, and animal bodies.
  • The text discusses various sources of Se biofortification, emphasizing Se-enriched yeast (Se-yeast), while also considering innovative alternatives like Se-enriched insects and Se-nanoparticles for animal nutrition.
  • It also provides insight into the legal regulations regarding Se in feed additives in regions like the EU, USA, and Canada, highlighting that sodium selenite and Se-yeast are the primary forms used, although other sources are being investigated for improved bioavailability and environmental benefits.
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Feed additives require pre-market authorisation prior to their use in the EU. For the group of coccidiostats, the EU regulations authorising these products include specifications for these substances and the major components of the feed additive formulations. Feed business operators can use only feed additives that meet these criteria.

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The performance characteristics of a multi-analyte method for the determination of all 10 carotenoids authorised as feed additives within the EU were assessed via an interlaboratory study. The analytical method is based on reversed phase high performance liquid chromatography (RP-HPLC) coupled to an optical detector set at 410 nm. The analysis is particularly challenging due to the presence of various stereoisomers of each carotenoid, and the use of these compounds via natural or synthetic formulations, requiring a special sample preparation.

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The demand for the development of fast, easy-to-use and low-cost analytical methods for food adulteration analysis has being increasing in the last years. Although infrared spectroscopic techniques offer these advantages, the validation of screening methods requiring the application of multivariate data treatment is less frequently described in literature thus limiting their use as routine tools in control laboratories for food fraud monitoring. In this paper, an EU-validation procedure for screening methods was successfully applied to a multivariate FT-NIR spectroscopic method for the screening of durum wheat pasta samples adulterated with common wheat at the screening target concentration of 3%.

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Phytase-based preparations are important feed additives currently authorised in the European Union (EU). The European Standard (EN) and International Organization for Standardization (ISO) standard 30024 describes a harmonized method for the determination of phytase activity and is fit-for-purpose for official control of a group of phytase products. However, it is not suitable for the determination of the phytase activity of a new feed additive encoded as 4a16 in the EU Register of Feed Additives, to which a slightly different phytase activity definition has been attributed.

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(AFB₁) in maize and wheat using LFD and LC-HRMS, respectively. The results of analyses were used to calculate intermediate precision (RSD, covering the inter-analyst variability in preparing the analytical samples and the precision under repeatability conditions) cut-off values and false suspect rates. RSD ranged from 6.

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The use of infrared spectroscopy for the screening of 229 unprocessed durum wheat samples naturally contaminated with OTA has been investigated. Samples were analysed by both Fourier Transform near- and mid-infrared spectroscopy (FT-NIR, FT-MIR). Partial-Least Squares-Discriminant Analysis (PLS-DA) and Principal Component-Linear Discriminant Analysis (PC-LDA) classification models were used to differentiate highly contaminated durum wheat samples from low contaminated ones and the performances of the resulting models were compared.

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Diclazuril is a coccidiostat currently authorized as feed additive in the European Union (EU), with a legal limit set at 1 mg/kg. For official control, an official EU method based on reversed-phase HPLC coupled with UV detection at 280 nm needs to be applied. Recently, the EU Reference Laboratory for feed additives was informed that the recovery rate for diclazuril was very low when implementing this method and performed experiments demonstrating that the indicated sorbent mass of the solid-phase extraction (SPE) was too low.

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Background: Deoxynivalenol (DON) is the most common Fusarium mycotoxin occurring in wheat and wheat-derived products, with several adverse and toxic effects in animals and humans. Although bran fractions produced by milling wheat have numerous health benefits, cereal bran is the part of the grain with the highest concentration of DON, thus representing a risk for consumers. Increased efforts have been made to develop analytical methods suitable for rapid DON screening.

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Feed additives need to be authorised to be placed on the market according to Regulation (EU) No. 1831/2003. Next to laying down the procedural requirements, the regulation creates the European Union Reference Laboratory for Feed Additives (EURL-FA) and requires that applicants send samples to the EURL-FA.

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Carotenoids are used in animal nutrition mainly as sensory additives that favourably affect the colour of fish, birds and food of animal origin. Various analytical methods exist for their quantification in compound feed, reflecting the different physico-chemical characteristics of the carotenoid and the corresponding feed additives. They may be natural products or specific formulations containing the target carotenoids produced by chemical synthesis.

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This paper describes the operation of the European Union Reference Laboratory for Feed Additives (EURL) and its role in the authorisation procedure of feed additives in the European Union. Feed additives are authorised according to Regulation (EC) No. 1831/2003, which introduced a completely revised authorisation procedure and also established the EURL.

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Coccidiostats belong to the group of feed additives authorised within the European Union exclusively for specific preparations. These preparations not only contain one or more coccidiostats as active substance(s) but also various ingredients such as the carrier, which are included in the European legislation authorising the product. In order to allow the full traceability of the use of feed additives and to check for compliance with legal provisions, there is a strong need for analytical methods that enable the rapid characterisation of these products.

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Tropane alkaloids (TAs) are toxic secondary metabolites produced by plants of, inter alia, the genera Datura (thorn apple) and Atropa (deadly nightshade). The most relevant TAs are (-)-L-hyoscyamine and (-)-L-scopolamine, which act as antagonists of acetylcholine muscarinic receptors and can induce a variety of distinct toxic syndromes in mammals (anti-cholinergic poisoning). The European Union has regulated the presence of seeds of Datura sp.

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Pyrrolizidine alkaloids (PAs) are a group of plant secondary metabolites with carcinogenic and hepatotoxic properties. When PA-producing plants contaminate crops, toxins can be transferred through the food chain and cause illness in humans and animals, most notably hepatic veno-occlusive disease. Honey has been identified as a direct risk of human exposure.

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Distillers Grain (DG) is an important by-product of ethanol production. The ethanol production process uses only the starch portion of the plant and all the remaining nutrients, protein, fat, minerals, and vitamins remain in DGs, a valuable feed material for livestock. The use of antimicrobial drugs is helpful to limit harmful bacterial growth during the early part of the fermentation process.

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In this paper, we report the inter-laboratory validation (ILV) of a recently developed indirect competitive multiplex dipstick (Bee4sensor®) which is capable of the simultaneous detection of residues of some of the most frequently detected antibiotic residues in honey: sulfonamides, tylosin, fluoroquinolones and chloramphenicol. The multi-sensor dipstick can be interpreted via visual observation or by an instrumental measurement of four test lines. Statistical analysis of the ILV data demonstrated that the multi-sensor can reliably detect the presence of sulfathiazole at 25 μg kg(-1) and tylosin at 10 μg kg(-1), which fully meet the 'recommended concentrations' of the EU.

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The emerging trend towards full scan mass spectrometry alternatives was evaluated for the identification of a wide range of anti-bacterial compounds in animal feed. The high resolving power of the orbitrap exactive provides precise mass accuracy, resulting in high selectivity which enables qualitative and quantitative analysis in complex matrices such as feed. A simple generic sample preparation procedure was applied, including extraction of the feed samples with a combination of organic solvents.

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The benefits of using rapid qualitative methods to verify compliance of food and feed with legislation requirements include user-friendly format, the possibility of detection without expensive instrumentation, rapid response and affordable price. Prior to their use, however, the methods have to pass validation experiments, in order to assess their performance profile. An experimental protocol for in-house validation of a screening immunoassay has been designed and applied to evaluate performance characteristics of a multiplex dipstick kit for the determination of major Fusarium toxins, namely zearalenone, T-2 and HT-2 toxins, deoxynivalenol and fumonisins in wheat and maize.

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The performance characteristics of a method based on HPLC with postcolumn derivatization and spectrophotometric detection for the quantification of semduramicin in poultry feedingstuffs have been determined via a collaborative study. Semduramicin is a feed additive that is authorized for fattening chickens within the European Union at a minimum and maximum content of 20 and 25 mg/kg in feedingstuffs, respectively. The target concentration of semduramicin in the test samples ranged from 11.

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