Method EN Research Articles

A Comparative Study of Biodiesel Production from Waste Cooking Olive Oil and Sunflower Oil

AbstractWaste cooking oils are commonly utilized as feedstock in biodiesel synthesis. However, there has been limited research on the perspective of using waste cooking olive oil for biodiesel production. This study explores the potential of household waste frying olive oil as a feedstock for biodiesel production andcomparing it with sunflower oil. The biodiesel samples were evaluated according to European standard specifications and test methods EN 14214. However, the water content and oxidation stability did not meet the required criteria. To address this, the Rancimat method was used to investigate the potential of essential oils and plant extracts as antioxidants. Oregano essential oil and rosemary plant extracts significantly improved the oxidation stability of both olive and sunflower oil biodiesel. The analysis of the fatty acid profile of the feedstock through gas chromatography–mass spectrometry proved to be a critical determinant of biodiesel properties. Moreover, the use of ultrasound‐assisted biodiesel synthesis enhanced the yield of biodiesel. The research findings have indicated that olive oil is a sustainable option to produce high‐yield biodiesel with a noteworthy antioxidant stability when natural antioxidants are incorporated into the mixture.

Increased rupture of cypress pollen type due to atmospheric water in central and southeastern Spain

This study aims to investigate the meteorological variables determining Cupressaceae pollen grain disruption in the environment. A parallel sampling of pollen grains and disrupted Cupressaceae pollen grains was performed in six cities using two Spanish aerobiological networks. The pollen concentrations, disrupted pollen concentrations, percentage of disrupted pollen and number of days when the percentage of disrupted pollen was above or equal to 50 % were quantified during two pollen seasons. The concentrations were determined following the standardised method EN 16868. Results show that the concentrations of pollen grains and disrupted pollen grains were not determined by geographical features and rarely by bioclimatic variables or indexes but by the ornamental use of the specimens in the vicinity of the pollen sampler, highlighting the possibility of using management practices to reduce exposure to allergens in the cities. African dust outbreaks coincided with higher concentrations of pollen grains and disrupted pollen grains, but the reduced percentage of disrupted pollen grains pointed to a non-causal relationship with long-distance transport. The effect of wind and maximum gusts remained negligible. The triggering factor for pollen disruption was the amount of water in the atmosphere, mainly reported as relative humidity. Rainfall increased the effect of disruption due to pollen grain swelling caused by its wash-out effect. The higher the relative humidity, the higher the disrupted pollen concentrations. This aligns with the mechanism of Cupressaceae reproduction since the family needs a water medium in the form of pollination droplets for the pollination tube to develop and the pollen grain to perform its biological function. Therefore, people that develop allergic symptoms to Cupresaceae pollen should avoid exposure during days with high relative humidity in the main pollen season.

Occurrence and health risk estimate of organochlorine pesticides in fruits and vegetables matrices.

Occurrence of 20 organochlorine pesticides (OCPs) in 60 organic and non-organic fruits and vegetables matrices was undertaken using QuEChERS Method EN 15662 for sample preparation analyzed by gas chromatography-mass spectrometry (GC-MS/MS). The procedural method was validated by spiking the OCP standard solutions at three fortified levels at 10, 50, and 100 µg/kg wet weight (ww) to the real matrix of fruit and vegetable with good recovery ranging from 75 to 108% with relative standard deviation (RSD) ≤ 11%, and the limits of detection and quantification (LODs and LOQs) were 0.002-0.02μg/kg and 0.004-0.1μg/kg ww, respectively. The assessment of health risks associated with pesticide residues through consumption of vegetables and fruits and the effect of washing and peeling on concentration of various pesticides were also studied. The results showed that the concentration levels of 60% of samples were lower than the LOQs, while the rest was contaminated by OCP residues. Organic fruits and vegetables showed the absence of OCPs, while several of the studied compounds were detected from conventional agriculture. Skin removal (peeling) was the most effective strategy to eliminate or decrease pesticide residues, and should be one of the solutions to reduce the health impact of pesticides in fruits and vegetables. The analysis of health risk assessment was based on the use of the estimated average daily intake (EDI), hazard index (HI), and hazard ratio (HR) for individuals in two weight categories: children (weighing 16.7kg) and adults (weighing 60kg). The HI values were less than 1 suggesting that there was no probable non-carcinogenic health effect, except for heptachlor for children (HI of 1.285). However, the values of HR revealed that children were more susceptible to the carcinogenic health effect associated with consuming contaminated vegetables.

Fire Safety for Green Façades: Part 1: Basics, State-of-the-Art Research and Experimental Investigation of Plant Flammability

This study is the first part of a larger investigation into the fire behaviour of green façades. In this study, the currently known international research status on this topic is presented and discussed. In addition, the flammability of green façades is investigated through 43 fire tests on a medium scale according to the SBI (Single Burning Item) test method EN 13823. The focus of the investigation was placed on climbing plants. A total of 25 different plant species were investigated. A comparison of the heat release rate of all the investigated vital plants shows similar behaviour. In the course of exposure, there are short peaks in the heat release rate. These peaks are “flare-ups” that occur when parts of the plants dry out due to exposure to the flame and then ignite. The plant species itself had no substantial influence on fire behaviour. Horizontal fire spread occurred to a very limited extent within the investigations of vital plants. They were self-extinguishing. The significant factor in the assessment of flammability is the moisture content of the plants. With dried plants, an abrupt heat release occurs at the beginning. Dried-out plants, as well as unmaintained plants with a high content of deadwood, represent the most critical case.Graphical

First Synthesis of Ergotamine-13CD3 and Ergotaminine-13CD3 from Unlabeled Ergotamine.

Ergot alkaloids (EAs) formed by Claviceps fungi are one of the most common food contaminants worldwide, affecting cereals such as rye, wheat, and barley. To accurately determine the level of contamination and to monitor EAs maximum levels set by the European Union, the six most common EAs (so-called priority EAs) and their corresponding epimers are quantified using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The quantification of EAs in complex food matrices without appropriate internal standards is challenging but currently carried out in the standard method EN 17425:2021 due to their commercial unavailability. To address the need for isotopically labeled EAs, we focus on two semi-synthetic approaches for the synthesis of these reference standards. Therefore, we investigate the feasibility of the N6-demethylation of native ergotamine to yield norergotamine, which can subsequently be remethylated with an isotopically labeled methylating reagent, such as iodomethane (13CD3-I), to yield isotopically labeled ergotamine and its C8-epimer ergotaminine. Testing the isotopically labeled ergotamine/-inine against native ergotamine/-inine with HPLC coupled to high-resolution HR-MS/MS proved the structure of ergotamine-13CD3 and ergotaminine-13CD3. Thus, for the first time, we can describe their synthesis from unlabeled, native ergotamine. Furthermore, this approach is promising as a universal way to synthesize other isotopically labeled EAs.

Development and efficacy assessment of hand sanitizers and polylactic acid films incorporating caffeic acid and vanillin for enhanced antiviral properties against HCoV-229E

BackgroundAlthough three years after the outbreak of SARS-CoV-2, the virus is still having a significant impact on human health and the global economy. Infection through respiratory droplets is the main transmission route, but the transmission of the virus by surface contact cannot be ignored. Hand sanitizers and antiviral films can be applied to control SARS-CoV-2, but sanitizers and films show drawbacks such as resistance of the virus against ethanol and environmental problems including the overuse of plastics. Therefore, this study suggested applying natural substrates to hand sanitizers and antiviral films made of biodegradable plastic (PLA). This approach is expected to provide advantages for the easy control of SARS-CoV-2 through the application of natural substances.MethodsAntiviral disinfectants and films were manufactured by adding caffeic acid and vanillin to ethanol, isopropyl alcohol, benzalkonium chloride, and PLA. Antiviral efficacies were evaluated with slightly modified international standard testing methods EN 14,476 and ISO 21,702.ResultsIn suspension, all the hand sanitizers evaluated in this study showed a reduction of more than 4 log within 2 min against HCoV-229E. After natural substances were added to the hand sanitizers, the time needed to reach the detection limit of the viral titer was shortened both in suspension and porcine skin. However, no difference in the time needed to reach the detection limit of the viral titer was observed in benzalkonium chloride. In the case of antiviral films, those made using both PLA and natural substances showed a 1 log reduction of HCoV-229E compared to the neat PLA film for all treatment groups. Furthermore, the influence of the organic load was evaluated according to the number of contacts of the antiviral products with porcine skin. Ten rubs on the skin resulted in slightly higher antiviral activity than 50 rubs.ConclusionThis study revealed that caffeic acid and vanillin can be effectively used to control HCoV-229E for hand sanitizers and antiviral films. In addition, it is recommended to remove organic matter from the skin for maintaining the antiviral activity of hand sanitizer and antiviral film as the antiviral activity decreased as the organic load increased in this study.

Glycerol and monoglycerides determination in biodiesel methyl ester from palm oil using gas chromatography

Monoglycerides and glycerol are by-products contaminants, after transesterification, in biodiesel that can lead to severe operational and engine problems such as wax precipitation, filter plugging and engine deposits. Therefore, strict regulations have been made, and accurate quality control is required. In this work, levels of monoglycerides and glycerol were determined using gas chromatography (GC) equipment with flame ionization detector (FID) refers to standard methods ASTM D6584 and EN 14105. However, the monoglycerides determination still needs firmness and validation to develop standard calibration series to fit the constituent fatty acid components of the feedstock used. This paper shows three fatty acids, i.e., monoolein, monopalmitin, and monostearin, as major components in palm-based biodiesel, which would be prepared as standard calibration and determined from commercial biodiesel samples in the determination of monoglyceride levels accurately and thoroughly. The result shows that standard solutions produce a curve with high linearity; it was above 0.998 (for free glycerol, monopalmitin, monoolein, and monostearin) and its accuracy values were >95%. However, the result for eight commercial biodiesel samples in Indonesia had a range of 0.23-0.54% w/w for total monoglycerides, 0.07 to 0.14 (% w/w) for total glycerol, and < 0.01% w/w for free glycerol, which was fulfilling to the ASTM D6751 and EN 14214 specification requirements.

Quantification of Ergot Alkaloids via Lysergic Acid Hydrazide-Development and Comparison of a Sum Parameter Screening Method.

Ergot alkaloids are a group of mycotoxins occurring in products derived from various grasses (e.g., rye) and have been regulated in the EU recently. The new maximum levels refer to the sum of the six most common ergot alkaloids in their two stereoisomeric forms in different food matrices. Typically, these twelve compounds are individually quantified via HPLC-MS/MS or -FLD and subsequently summed up to evaluate food safety in a time-consuming process. Since all these structures share the same ergoline backbone, we developed a novel sum parameter method (SPM) targeting all ergot alkaloids simultaneously via lysergic acid hydrazide. After extraction and clean-up, in analogy to the current European standard method EN 17425 (ESM) for ergot alkaloid quantitation, the samples were derivatized by an optimized hydrazinolysis protocol, which allowed quantitative conversion after 20 min at 100 °C. The new SPM was evaluated against another established HPLC-FLD-based method (LFGB) and the HPLC-MS/MS-based ESM using six naturally contaminated rye and wheat matrix reference materials. While the SPM provided comparable values to the ESM, LFGB showed deviating results. Determined recovery rates, limits of detection and quantification of all three employed methods confirm that the new SPM is a promising alternative to the classical approaches for ergot alkaloid screening in food.

Characterizing noise barriers: SOPRANOISE final report and outcomes

SOPRANOISE targets a three-step approach for assessing the in-situ intrinsic acoustic performance of road/railway noise barriers in regard to airborne sound insulation and sound reflection under direct sound field conditions. This approach goes from the in-situ inspections method (targeting at the acoustic effect in the far-field) to the standardized measuring methods EN 1793-5 and 6, with "quick and safe" measuring methods in between. Papers about SOPRANOISE have already been presented in 2020 and 2021 as progress reports. The research ended in February 2022 and the final outcomes are now presented. The main part of the pending work has been done within Work Package 4 (WP4). Herein, a new "quick and safe" method was designed and validated both in the lab and in situ. The new measuring equipment is portable, lightweight and uses a linear antenna; the measurement itself is fully automated and the results show a very good correlation with full EN 1793-5/-6 results. WP4 results are particularly successful and, together with the in-situ inspection, those methods are ready to be submitted to the relevant CEN/TC226/WG6 working group to draft a new framework on noise barriers assessment. All main reports are public available on the SOPRANOISE and CEDR webpages.

CFD Comparison of the Influence of Casting of Samples on the Fiber Orientation Distribution

The main goal of this research is to show that even a small deviation from the prescribed casting method EN 14651 causes a difference in fiber orientation distribution in sample beams. A further goal is to investigate the difference in the fiber orientation between bottom and side layers, which would carry the tensile load in the in-situ situation (bottom layer) compared to testing according to EN 14651 (side layer). Nowadays, the development of the proper numerical simulations that aim to visualize the casting process of the fresh concrete flow is a promising challenge in the construction industry. To be able to predict the orientation and spatial distribution of the short fibers using numerical tools may significantly simplify the investigations of the fibered composite materials. This paper compares simulations of different casting methods of the fiber concrete mixture with various flowabilities. The casting of the testing specimen was simulated in different ways: the filling of the formwork according to EN 14651, from the center only and from one edge of the formwork using computational fluid dynamics. The influence of different casting methods in combination with four specific sets of the rheological parameters on the final fiber orientation distribution is discussed. The presented outcomes of the simulations demonstrate that even a minor change in the casting procedure can significantly alter the final characteristics of the material.

The Investigation of the Efficacy of Some Antiseptics and Disinfectants to Vancomycin-Resistant Enterococci

Disinfection of contaminated material, surface and body parts with appropriate substances is one of the most effective practices in preventing the infection-colonization of Vancomycin-Resistant Enterococci (VRE). In this study, 1/10 and 1/100 dilutions of 5% sodium hypochlorite, 4% concentration of chlorhexidine gluconate and 0.1% and 0.5% concentrations of Akacid plus’s efficacy against VRE strains at 1, 5, 15 and 30 minutes was tested. Sixty-nine vancomycin-resistant E. faecium strains isolated from different body samples between 2012 and 2014 were included in the study. The BD Phoenix 100® fully automated system was used for the identification of strains and detection of vancomycin resistance. Quantitative Suspension Test method EN 1276 (March 2010) was used to evaluate the bactericidal activities of chemical disinfectants and antiseptics used in European Union countries in the investigation of disinfectant susceptibility of VRE strains. Five log10 decrease (105) in the number of bacteria in the initial test suspension between the number of bacteria after using the disinfectant indicates that the disinfectant is effective. In this study, it has been determined that a 1/10 dilution of 5% sodium hypochlorite (bleach) is the most effective disinfectant on VREs in all minutes and conditions. Effectiveness of 1/100 dilution of bleach has a significant decrease in dirty conditions. Akacid plus was not effective on all strains in any contact times we tested. It has been observed that Akacid plus is the disinfectant least affected by the changes in environmental conditions in all minutes. Chlorhexidine gluconate (4%) was ineffective in clean and dirty conditions in just 1 minute, while from the 5th minute, its effectiveness was found to be statistically at the same level as the 1/10 dilution of bleach. There was no decrease in the activities of chlorhexidine due to the changing environmental conditions. In conclusion, it has been determined that a 1/10 dilution of 5% sodium hypochlorite (bleach) is the most effective disinfectant on VREs in all minutes and conditions, but dirty environmental conditions cause a significant decrease in the effectiveness of sodium hypochlorite. In addition, it was observed that the effectiveness of all disinfectants and antiseptics on VREs increased as the contact time with the substances increased.

Monitoring of pesticides residues in fruits and vegetables: Method optimization and application

QuEChERS CEN Standard Method EN 15662 method was used with some modification for better efficiency of the extraction and purification of pesticides residues in fruits and vegetables matrix. The extracts were analyzed by GC–MS/MS for 14 multiclass pesticides in fruits and vegetables. The method was validated with real matrix with good efficiency ranging from 73 to 124% and the LODs and LOQs were 0.001–0.4 μg kg−1 and 0.002–1.0 μg kg−1 respectively. The method was applied to investigate the level of pesticide residues in 58 fruits and vegetables and with four condition: with and without washing, with and without skin. This condition is to simulate the condition how people consume fruits and vegetables and to find out if with the sample act, the level of pesticides can be reduced. This studied confirmed the absences or lower concentration of pesticides in organic fruits and vegetables compared to which originated from intensive agricultural where pesticides are widespread used. The results were then compared to the maximum residue limits for each pesticides and in each matrix. Our results allow to conclude that washing or removing skin should be one of the solution to reduced health impact related to pesticide in fruits and vegetables.

Effect of storage temperature on quality parameters of liquid organic fertilizer prepared from Mexican sunflower (Tithonia diversifolia)

Objectives: To determine the effect of storage temperature on physical-chemical properties of tithonia liquid organic fertilizer. To determine the effect of storage temperature on microbial population in tithonia liquid organic fertilizer. To evaluate the effect of tithonia liquid organic fertilizer on kales crop. Problem Statement: Tithonia diversifolia has been used as green manure in soil fertilization and improvement of crop performance. Attempts have been made to extracts tithonia liquid organic fertilizer (LOF) to ease storage and transport. However, not much was known about quality parameters of liquid organic fertilizer (LOF) during storage. This study established the effect of storage temperature on the quality parameters of LOF from Tithonia diversifolia. Methodology: Tithonia LOF was prepared by fermenting 2 kg of tithonia leaves in 20litres of water for 2 weeks to maintain leaf water ratio of 1:10. The fermented extract was filtered using a clean cloth and transferred into 36 one litre specimen jars. Eighteen of the specimen jars were placed in the refrigerator at temperature of 00 C to 50 C while another batch of 18 in the specimen cabinet at room temperature at 230C. Specific laboratory analysis procedures were used to determine the nutritional chemical content of the sampled LOF. Total nitrogen(N) was analyzed by ISO 5315-trimetric method, phosphorus (P) by ultraviolet visible spectrophotometer at λ-420nm, and potassium (K) by AAS ISO17319:2015. Other chemical analysis done were Magnesium (Mg) using method EN 16197:2012 AAS, Calcium by ISO method 17025 AAS and total reducing sugars by normal- phase chromatography HPLC method. The pH of the LOF was analyzed by handheld pH meter. Microbial analysis used plate count agar for bacterial and potato dextrose agar (PDA) for fungus count. Kale plants were arranged in a randomized block design of 9 plots each with 9 potted plants. The treatment was replicated three times for samples stored in the refrigerator and three times for the room temperature storage repeatedly for six months. Plant parameters measured were; plant height, number of leaves and the plant girth. Key findings: The study established that there was a significant change in LOF pH during storage, however correlation was higher for room storage than fridge storage. The study also established that there was no significant change in chemical properties of LOF in both storage conditions however, the room stored LOF had negative correlation with storage time an indicating that plant nutrients in LOF reduced with increase in storage time. In regards to microbial properties, it was found that there was no significant change in microbial count in LOF in both storage temperature experiments. The study also established that treatment of kales with LOF stored at room temperature had higher growth variance than for the fridge stored and control treatment. Discussion There was a significant change in LOF pH during storage where p=0.012. Correlation was higher for room storage than fridge storage. Freshly prepared LOF was slightly acidic at pH 6.5 attaining pH 7.88 and 7.1 at room and fridge temperatures respectively. Change in chemical properties of LOF in both storage conditions was not significant whereas, the room stored LOF had negative correlation with storage time indicating how plant nutrients in LOF reduced with increase in storage time. The microbial count in LOF in both storage temperature experiments had no significant change. The relationship between microbial count and storage period was weak. Application: This study is useful to organic agriculture farmers, researchers and policy makers. Conclusion: The study established that the quality of LOF during storage deteriorated. LOF stored in room temperature reduced in quality faster than the refrigerated one. Therefore, the quality of the LOF is best when freshly prepared. Despite kales performing marginally better when treated with room stored LOF, there was no significant difference with fridge stored LOF. Investment in cold storage of LOF therefore does not make economic sense. Recommendation: The study recommends further research on effect of LOF concentration on crop growth to ensure optimum nutrients for production.

Development of a Hydrazine-Based Solid-Phase Extraction and Clean-Up Method for Highly Selective Quantification of Zearalenone in Edible Vegetable Oils by HPLC-FLD.

Rapid, cost-efficient, and eco-friendly methods are desired today for routine analysis of the Fusarium mycotoxin zearalenone (ZEN) in edible vegetable oils. Liquid chromatography with fluorescence detection (HPLC-FLD) is commonly used to reliably control the specified ZEN maximum levels, which requires efficient sample clean-up to avoid matrix interferences. Therefore, a highly selective extraction and clean-up method based on reversible covalent hydrazine chemistry (RCHC) using hydrazine-functionalized silica was developed. This efficient solid-phase extraction (SPE) involves reversible hydrazone formation of ZEN with the hydrazine moiety covalently bound to a solid phase. Optimal conditions were achieved with 1 mL SPE cartridges filled with 400 mg of hydrazine-functionalized silica. The developed RCHC-SPE method was validated in an interlaboratory comparison study (ILC) with twelve participants analyzing six edible vegetable oils with a focus on maize oils. The derived method parameters (ZEN recovery 83%, repeatability 7.0%, and reproducibility 18%) meet the performance criteria of Commission Regulation (EC) No 401/2006. The developed RCHC-SPE-based HPLC-FLD method allows the reliable quantification of ZEN in the range of 47–494 µg/kg for different types of edible vegetable oils, also for matrix-reach native oils. Due to the high efficiency, the significantly reduced matrix load helps to extend the lifetime of analytical equipment. Furthermore, the re-useability of the RCHC-SPE cartridges contributes to an eco-friendly approach and reduced analysis costs. To our knowledge, this is the first report on ZEN quantification in edible vegetable oils based on manual RCHC-SPE cartridges. Due to its high performance, the developed RCHC-SPE method is a promising alternative to the current European standard method EN 16924:2017 (HPLC-FLD part).

Development of a simple HPLC procedure for the determination of prochloraz residues in mushrooms

Abstract A simple HPLC-UV procedure is described in our paper which is suitable for the rapid and cost-efficient determination of prochloraz in mushrooms. Prochloraz is the only fungicide in EU which use is allowed in mushroom production. The aim of our work was the development of a simple method that is suitable for the control of this pesticide in everyday analyses during mushroom production. The procedure involves a simple sample preparation method based on solid-liquid extraction (modified QuEChERS extraction method EN 15662) followed by an HPLC-UV determination (recovery: 97–99%; limit of detection LOD: 0.01 mg/kg; limit of quantification LOQ: 0.05 mg/kg).

Comparative Efficacy Evaluation of Quaternary Ammonium Disinfectants as Per EN 1040:2005

Microbial infections are the most complicated challenges of modern-day medical practices. Such infections become fatal when acquired from hospitals or other health care facilities. To tackle the challenges of hospital-acquired infections (HAIs), different classes of chemical disinfectants are used. Out of these chemical disinfectants, Quaternary Ammonium Compounds (QACs) based disinfectants are widely used because of their advantageous properties. Large-scale use of QACs led to reporting of resistance. To further enhance the efficacy and reduce toxicity, manufacturers of QACs developed newer compounds. However, disinfectants in hospitals are solely used in good faith and hospitals don't have an adequate policy to see the efficacy using standardized methods. Efficacy testing of QACs disinfectant is very important to reduce HAIs. Hence, bactericidal activities of different generation QACs disinfectants were evaluated as per the standardized method EN 1040. All QACs disinfectants demonstrated more than 5 log reductions and complied with the requirement of EN 1040.

Inactivation of SARS-CoV-2 by Commercially Available Disinfectants and Cleaners.

The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a major burden for health care systems worldwide, and is a threat to our daily lives. Various effective ingredients against SARS-CoV-2 were already reported, however, since products contain various ingredients, it is also important to evaluate the effectiveness of commercially available disinfectants per se. In this study, the virucidal efficacy of forty-eight commercially available products were evaluated according to the standardized suspension method EN 14476 and the following results were obtained: Alcohol-based disinfectants, hand soaps, wet wipes, alkaline cleaners, quaternary ammonium compound sanitizers and oxygen bleach had great virucidal efficacy against SARS-CoV-2. Enveloped viruses such as SARS-CoV-2 are among the most susceptible of pathogens to formulated microbicidal actives and detergents, but as the results of this study showed, it is also necessary to pay attention to the concentration at the time of use and the required contact time.

The European Standard Reference Method systematically underestimates particulate matter in stack emissions

For the quantification of particulate matter (PM) emitted into the atmosphere from industrial plants, reliable sampling methods are required. We have studied systematic errors in PM emission measurements performed according to the standard EN 13284-1, the legally required method in Europe for PM measurements of low concentrations in ducted gaseous streams. We analyzed a unique data set, covering 1614 PM samplings performed on a stack simulator, where the actual PM concentration was determined independently and traceably, allowing us to gain insight not only into the variability of the results obtained, but also into trueness of the measured PM concentrations. We found that the European Standard Reference Method (SRM) EN 13284-1 as applied by practitioners underestimates PM concentrations systematically by 13%. By varying the suction velocity into the sampling nozzles, as well as the nozzle geometry, we determined two main contributions for the underreporting of PM concentrations. First, the widespread practice by operators to perform PM sampling at 5% superisokinetic suction velocity leads to lower measured PM concentrations, which accounts for ca. one third of the underestimate. And second, the bulkiness of the nozzles generally used, which are not thin walled enough to allow representative sampling, with the use of bulky nozzles accounting for additional one third of the underreporting. • Systematic biases of the standard EN 13284-1 were studied at a stack simulator. • Dust sampling in stack emissions using this standard underreports particulate matter mass concentrations by 13%. • The generous limits on the deviation from isokinetic sampling are a major cause for underreporing. • The geometry of the sampling nozzles is another main cause for systematic underreporting.

Development and validation of the Standard method EN ISO 19020 - microbiology of the food chain — Horizontal method for the immunoenzymatic detection of staphylococcal enterotoxins in foodstuffs

In the frame of the CEN Mandate M/381 from the European Commission to CEN (European Committee for Standardization), a method for the detection of staphylococcal enterotoxins in foodstuffs has been developed, validated and standardized. An extraction procedure based on dialysis concentration followed by an immuno-enzymatic detection has been defined. In addition, performance criteria (minimum values of sensitivity, specificity and level of detection) to be achieved by the commercially available immuno-enzymatic kits that could be used to detect staphylococcal enterotoxins in food matrices, were developed. A 2-stage validation study was conducted: The first stage aimed at selecting the commercial kits to be included in the second stage, which consisted in an interlaboratory study, using eight matrices covering five food categories (ready-to-eat food, meat products, milk products, dessert and fish). Results showed that two detection kits included in the study met the pre-defined performance criteria. The implementation of dialysis concentration step increased significantly the sensitivity of the method. The method developed allowed to achieve the Benchmark Dose lower limit (BMD10) estimated at 6.1 ng. In 2019, finally, the European Commission recognized this standard as the European Union reference method for the detection of staphylococcal enterotoxins in food.

Radial Peripapillary Capillary Plexus Sparing and Underlying Retinal Vascular Impairment in Intermediate Age-Related Macular Degeneration

PurposeTo examine location-specific retinal vascular changes in intermediate age-related macular degeneration (iAMD) using age-matched, high-density en face optical coherence tomography angiography (OCTA) cluster analysis.MethodsEn face OCTA images of the 6 × 6 mm macular area were retrospectively acquired from 60 iAMD eyes and 60 age-matched normal eyes and then subdivided into 126 × 126 (47.62 × 47.62 µm) grids within the superficial and deep vascular complex. Grid-wise vessel perfusion (VP) were compared between iAMD and normal eyes from the corresponding 10-yearly age cohort, forming difference plots. Difference plots were further separated by normative topographical map spatial clusters (C1-6), derived from normaldatabase eyes (n = 236, 20–81 years old).ResultsOverall difference plots showed decreased VP in the superficial (−12.19%) and deep vascular complex (−6.44%) of iAMD compared to normal eyes (P < 0.0001 both comparisons). Cluster-based difference plots highlighted nonuniform changes in the superficial vascular complex, with sparing of VP at the nasal macula (corresponding to the radial peripapillary capillary plexus) versus decreased VP toward the temporal macula and foveal avascular zone (FAZ) (C1–6 all comparisons P < 0.0001, except C1 vs. C2 P > 0.99 and C4 vs. C5 P = 0.11). The deep vascular complex displayed diffusely decreased VP, greater at the FAZ (P < 0.0001).ConclusionsHigh-density en face OCTA cluster analysis suggests relative sparing of the radial peripapillary capillary plexus and impairment of underlying retinal vasculature, supporting potential anterograde transsynaptic degeneration in iAMD. These location-specific data may better guide future diagnostic and management protocol of iAMD.