Sum Parameter Research Articles

Establishment of a method to expose and measure pollution in excised porcine skin with electron paramagnetic resonance spectroscopy

Health problems associated with the amount of air pollutants are increasing worldwide. Pollution damages not only the lungs; it also has an impact on skin health and is co-responsible for the development of skin diseases.Anti-pollution products are on the rise in the cosmetic market but so far, there is no established method to directly assess the impact of pollution on the skin and to test the efficacy of anti-pollution products.To address this problem, two different chambers were developed for the reproducible exposure to realistic air pollutant concentrations. One chamber for the exclusive use of excised skin and hair samples, the second chamber for ex vivo and in vivo measurements. Measurements of nicotine next to the investigated skin area allow conclusions to be drawn on the particle concentration to which the skin is exposed. Electron paramagnetic resonance spectroscopy, which enables the detection of free radicals in different systems, was applied to assess the hazard potential of pollution in the skin. A direct proof of the formation of free radicals in the skin by the model pollutant cigarette smoke could be demonstrated. An additional application of UV irradiation even increased the formation of free radicals in the skin seven-fold (sum parameter). Depending on the question of interest, the use of different spin probes allows various assessments of the radical formation in skin: the amount of radicals but also the antioxidant status of the microenvironment can be estimated.Using two exposure chambers, the direct formation of oxidative stress by cigarette smoke on ex vivo skin, with and without additional UV exposure, could be reproducibly examined. This measurement method is promising for the assessment of anti-pollution products and could allow a direct causal connection between pollutant, effect on the skin and the protective function of skin care products.

PhotoTOP: PFAS Precursor Characterization by UV/TiO2 Photocatalysis.

To unravel the complexity of per- and polyfluoroalkyl substances (PFAS) in products and environmental samples, sum parameters that provide relevant information on chemical characteristics are necessary since not all PFAS can be captured by target analysis in case of missing reference standards or if they are not extractable or amenable to the analytical method. Therefore, we evaluated photocatalysis (UV/TiO2) as a further total oxidizable precursor approach (PhotoTOP) to characterize perfluoroalkyl acid precursors via their conversion to perfluoroalkyl carboxylic acids (PFCAs). Photocatalysis has the advantage that no salts are needed, allowing direct injection with liquid chromatography-mass spectrometry without time-consuming and potentially discriminating sample cleanup. OH radicals were monitored with OH probes to determine the reactivity. For eight different precursors (diPAPs, FTSAs, FTCAs, N-EtFOSAA, PFOSA), mass balance was achieved within 4 h of oxidation, and also, in the presence of matrix, complete conversion was possible. The PhotoTOP was able to predict the precursor chain length of known and here newly identified precursors qualitatively when applied to two PFAS-coated paper samples and technical PFAS mixtures. The length of the perfluorinated carbon chain (n) was mostly conserved in the form of PFCAs (n-1) with only minor fractions of shorter-chain PFCAs. Finally, an unknown fabric sample and a polymer mixture (no PFAS detectable in extracts) were oxidized, and the generated PFCAs indicated the occurrence of side-chain fluorinated polymers.

TVOC - Revisited

TVOC (total volatile organic compounds) has been used as a sum parameter in indoor air sciences for over 40years. In the beginning, individual VOC concentrations determined by gas chromatography were simply added together. However, several methods for calculating TVOC have become established over time. To understand the manifold definitions of TVOC, one must trace the history of indoor air sciences and analytical chemistry. Therefore, in this work, the original approaches of TVOC are searched and explained. A detailed description of the measurement methods is followed by a critical evaluation of the various TVOC values and their possible applications. The aim is to give the reader a deeper understanding of TVOC in order to use this parameter correctly and to be able to better assess published results. In addition, related sum values such as TSVOC and TVVOC are also addressed. A milestone was the analytical definition of VOCs and TVOC in 1997. A list of VOCs that should at least be considered when calculating TVOC was also provided. This list represented the status at that time, is no longer up-to-date and is being updated by a European working group as part of a harmonization process. However, there is still confusion about the exact definition and reasonable application of TVOC. The signals of other sum parameters, measured with photoacoustics, flame ionization, photoionization or electrochemical sensors, are also often given under the term TVOC. It was recognized early that TVOC is not a toxicologically based parameter and is therefore only suitable for a limited number of screening purposes. Consequently, TVOC cannot be used in connection with health-related and odor-related issues. Nevertheless, such references are repeatedly made, which has led to controversial scientific discussions and even court decisions in Germany about the correct and improper use of TVOC.

Development of a scoring parameter to characterize data quality of centroids in high-resolution mass spectra

High-resolution mass spectrometry is widely used in many research fields allowing for accurate mass determinations. In this context, it is pretty standard that high-resolution profile mode mass spectra are reduced to centroided data, which many data processing routines rely on for further evaluation. Yet information on the peak profile quality is not conserved in those approaches; i.e., describing results reliability is almost impossible. Therefore, we overcome this limitation by developing a new statistical parameter called data quality score (DQS). For the DQS calculations, we performed a very fast and robust regression analysis of the individual high-resolution peak profiles and considered error propagation to estimate the uncertainties of the regression coefficients. We successfully validated the new algorithm with the vendor-specific algorithm implemented in Proteowizard’s msConvert. Moreover, we show that the DQS is a sum parameter associated with centroid accuracy and precision. We also demonstrate the benefit of the new algorithm in nontarget screenings as the DQS prioritizes signals that are not influenced by non-resolved isobaric ions or isotopic fine structures. The algorithm is implemented in Python, R, and Julia programming languages and supports multi- and cross-platform downstream data handling.

Discovery and quantification of plastic particle pollution in human blood

Plastic particles are ubiquitous pollutants in the living environment and food chain but no study to date has reported on the internal exposure of plastic particles in human blood. This study’s goal was to develop a robust and sensitive sampling and analytical method with double shot pyrolysis - gas chromatography/mass spectrometry and apply it to measure plastic particles ≥700 nm in human whole blood from 22 healthy volunteers. Four high production volume polymers applied in plastic were identified and quantified for the first time in blood. Polyethylene terephthalate, polyethylene and polymers of styrene (a sum parameter of polystyrene, expanded polystyrene, acetonitrile butadiene styrene etc.) were the most widely encountered, followed by poly(methyl methacrylate). Polypropylene was analysed but values were under the limits of quantification. In this study of a small set of donors, the mean of the sum quantifiable concentration of plastic particles in blood was 1.6 µg/ml, showing a first measurement of the mass concentration of the polymeric component of plastic in human blood. This pioneering human biomonitoring study demonstrated that plastic particles are bioavailable for uptake into the human bloodstream. An understanding of the exposure of these substances in humans and the associated hazard of such exposure is needed to determine whether or not plastic particle exposure is a public health risk.

Fatty Acid Determination in Human Milk Using Attenuated Total Reflection Infrared Spectroscopy and Solvent-Free Lipid Separation.

This study introduces the first mid-infrared (IR)-based method for determining the fatty acid composition of human milk. A representative milk lipid fraction was obtained by applying a rapid and solvent-free two-step centrifugation method. Attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy was applied to record absorbance spectra of pure milk fat. The obtained spectra were compared to whole human milk transmission spectra, revealing the significantly higher degree of fatty acid-related spectral features in ATR FT-IR spectra. Partial least squares (PLS)-based multivariate regression equations were established by relating ATR FT-IR spectra to fatty acid reference concentrations, obtained with gas chromatography-mass spectrometry (GC-MS). Good predictions were achieved for the most important fatty acid sum parameters: saturated fatty acids (SAT, R2CV = 0.94), monounsaturated fatty acids (MONO, R2CV = 0.85), polyunsaturated fatty acids (PUFA, R2CV = 0.87), unsaturated fatty acids (UNSAT, R2CV = 0.91), short-chain fatty acids (SCFA, R2CV = 0.79), medium-chain fatty acids (MCFA, R2CV = 0.97), and long-chain fatty acids (LCFA, R2CV = 0.88). The PLS selectivity ratio (SR) was calculated in order to optimize and verify each individual calibration model. All mid-IR regions with high SR could be assigned to absorbances from fatty acids, indicating high validity of the obtained models.

Effect of ozonation on the biodegradability of urban wastewater treatment plant effluent

The present work aimed to study the effect of ozonation on the organic sum parameters linked to enhanced biodegradability. Laboratory experiments were conducted with the effluent of four Austrian urban wastewater treatment plants with low food to microorganism ratios and different matrix characteristics. Biochemical oxygen demand over 5 days (BOD5) was measured before ozonation and after application of different specific ozone doses (Dspec) (0.4, 0.6 and 0.8 g O3/g DOC). Other investigated organic parameters comprised chemical oxygen demand (COD), dissolved organic carbon (DOC), UV absorption at 254 nm (UV254), which are parameters that are applied in routine wastewater analysis. Carbamazepine and benzotriazole were measured as reference micropollutants. The results showed a dose-dependent increase in biological activity after ozonation; this increase was linked to the enhanced biodegradability of substances that are recalcitrant to biodegradation in conventional activated sludge treatment. The highest relative change was determined for BOD5, which already occurred between 0 and 0.4 g O3/g DOC for all samples. Increasing the Dspec to 0.6 and 0.8 g O3/g DOC resulted in a less pronounced increase. DOC was not substantially decreased after ozonation, which was consistent with a low reported degree of mineralization, while partial oxidation led to a quantifiable decrease in COD (7 to 17%). Delta UV254 and the decline in specific UV absorption after ozonation clearly correlated with Dspec. In contrast, for COD and biodegradable DOC (BDOC), a clear dose-response pattern was identified only after exposure to BOD5 measurement. Indications for improved biodegradability were further supported by the rise in the BOD5/COD ratio. The results indicated that subsequent biological processes have a higher degradation potential after ozonation. The further reduction in biodegradable organic carbon emission by the combination of ozonation and biological post treatment represents another step towards sustainable water resource management in addition to micropollutant abatement.

Investigation of per- and polyfluoroalkyl substances (PFAS) in soils and sewage sludges by fluorine K-edge XANES spectroscopy and combustion ion chromatography

For the first time, fluorine K-edge X-ray absorption near-edge structure (XANES) spectroscopy was applied to detect per- and polyfluoroalkyl substances (PFAS) in various soil and sewage sludge samples. The method can be used to determine the speciation of inorganic and organic fluorides, without pre-treatment of solid samples. Therefore, XANES spectra of several inorganic fluorides as well as selected fluorinated organic compounds were recorded. While inorganic fluorides partially exhibit a variety of sharp spectral features in the XANES spectrum, almost all inspected organofluorine compounds show two distinct broad features at 688.5 and 692.0 eV. Moreover, the peak intensity ratio 688.5 eV/692.0 eV in the PFAS XANES spectrum can be inversely correlated to the chain length of the perfluoro sulfonic acid group. The detection of targeted PFAS by bulk-XANES spectroscopy in combination with linear combination fitting in soils and sewage sludges was not applicable due to the low organic fluorine to total fluorine ratio of the samples (0.01–1.84%). Nonetheless, direct analysis of pure PFAS revealed that analysis of organofluorine species might be achieved in higher concentrated samples. Furthermore, quantitative measurements by combustion ion chromatography (CIC) evaluated as sum parameters extractable organically bound fluorine (EOF) and total fluorine (TF) emphasize that besides soils, sewage sludges are a significant source of organic fluorine in agriculture (154–7209 µg/kg).

Elimination of micropollutants from municipal wastewater by adsorption on powdered activated carbon and separation by innovative precoat filtration

• PAC with smallest particle size ( x 50.3 = 10 µm) shows fastest adsorption kinetics. • The correlation of the UV 254 and trace substance removal is not given for powdered activated carbon made from coconut shells. • Background organic matter present in wastewater decreases trace substance removal. • Precoat filtration is a possible alternative for PAC separation. • A precoat of ≈ 0.5 kg∙m −2 cellulose to achieve a clear filtrate. Anthropogenic trace substances are residues from pharmaceuticals, detergents, care products and other areas of everyday use. Municipal wastewater treatment plants (WWTPs) are unable to remove these substances adequately and are therefore among the main emitters. The treatment of municipal wastewater with powdered activated carbon in combination with precoat filtration is a suitable downstream stage. Within the scope of this work, four powdered activated carbons (PACs) with different particle sizes in the range of 10–200 µm are compared (#1-#4). The sum parameters UV absorption at 254 nm (UVA 254 ), dissolved organic carbon (DOC), chemical oxygen demand (COD), as well as the analysis of seven trace substances, characterize the removal performance of the activated carbons. As result, only the PAC #4 with the smallest particle size ( x 50.3 ≈ 10 µm) shows a target-oriented reduction of the parameters from a concentration of 30 mg∙l −1 and a contact time of 30 min. The other carbons with higher particle size do not achieve sufficient removal rates. Due to the selectivity of the activated carbons towards trace substances, a correlation of trace substance removal is not given for every PAC. Besides, investigations on a continuously operated pressurized filter cell (PFC) for filtration of an activated carbon show the separation performance. A precoat of cellulose supplies the filtration process and can improve the backwashing application.

Pyrrolizidine Alkaloids in the Food Chain: Is Horizontal Transfer of Natural Products of Relevance?

Recent studies have raised the question whether there is a potential threat by a horizontal transfer of toxic plant constituents such as pyrrolizidine alkaloids (PAs) between donor-PA-plants and acceptor non-PA-plants. This topic raised concerns about food and feed safety in the recent years. The purpose of the study described here was to investigate and evaluate horizontal transfer of PAs between donor and acceptor-plants by conducting a series of field trials using the PA-plant Lappula squarrosa as model and realistic agricultural conditions. Additionally, the effect of PA-plant residues recycling in the form of composts or press-cakes were investigated. The PA-transfer and the PA-content of soil, plants, and plant waste products was determined in form of a single sum parameter method using high-performance liquid chromatography mass spectroscopy (HPLC-ESI-MS/MS). PA-transfer from PA-donor to acceptor-plants was frequently observed at low rates during the vegetative growing phase especially in cases of close spatial proximity. However, at the time of harvest no PAs were detected in the relevant field products (grains). For all investigated agricultural scenarios, horizontal transfer of PAs is of no concern with regard to food or feed safety.

Toxic effects of substituted p-benzoquinones and hydroquinones in in vitro bioassays are altered by reactions with the cell assay medium

Substituted para-benzoquinones and hydroquinones are ubiquitous transformation products that arise during oxidative water treatment of phenolic precursors, for example through ozonation or chlorination. The benzoquinone structural motive is associated with mutagenicity and carcinogenicity, and also with induction of the oxidative stress response through the Nrf2 pathway. For either endpoint, toxicological data for differently substituted compounds are scarce. In this study, oxidative stress response, as indicated by the AREc32 in vitro bioassay, was induced by differently substituted para-benzoquinones, but also by the corresponding hydroquinones. Bioassays that indicate defense against genotoxicity (p53RE-bla) and DNA repair activity (UmuC) were not activated by these compounds. Stability tests conducted under incubation conditions, but in the absence of cell lines, showed that tested para-benzoquinones reacted rapidly with constituents of the incubation medium. Compounds were abated already in phosphate buffer, but even faster in biological media, with reactions attributed to amino- and thiol-groups of peptides, proteins, and free amino acids. The products of these reactions were often the corresponding substituted hydroquinones. Conversely, differently substituted hydroquinones were quantitatively oxidized to p-benzoquinones over the course of the incubation. The observed induction of the oxidative stress response was attributed to hydroquinones that are presumably oxidized to benzoquinones inside the cells. Despite the instability of the tested compounds in the incubation medium, the AREc32 in vitro bioassay could be used as an unspecific sum parameter to detect para-benzoquinones and hydroquinones in oxidatively treated waters.

Effect-directed profiling of 32 vanilla products, characterization of multi-potent compounds and quantification of vanillin and ethylvanillin

Food testing is of great importance to the food industry and organizations to verify the authenticity claims, to prove the quality of raw materials and products, and to ensure food safety. The market prices of vanilla differed by a factor of about 20 in the last three decades. Therefore the risk of adulteration and counterfeiting of vanilla products is high. Instead of commonly used target analyses and sum parameter assays, a complementary non-target multi-imaging effect-directed screening was developed, which provided a new perspective on the wide range of vanilla product qualities on the market. Planar chromatography was combined with effect-directed assays, and the obtained biological and biochemical profiles of 32 vanilla products from nine different categories revealed a variety of active ingredients. Depending on the region, typical vanilla product profiles and activity patterns were obtained for pods, tinctures, paste (inner part), oleoresin and powders. However, some vanilla products showed additional active compounds and a different intensity pattern. The vanilla product profiles substantially differed from those of vanilla aroma or products containing synthetic vanillin or vanilla-flavored food products. Bioactive compounds of interest were online eluted and further characterized via HPTLC−HRMS, which allowed their tentative assignment. After purchase of the standards, these were successfully confirmed by co-chromatography. Quantification of vanillin across nine different product categories revealed levels ranging from 1 µg/g to 36 mg/g with a mean repeatability of 1.9%. The synthetic ethylvanillin was not detected in the investigated samples in significant concentrations. The assessment of differences in the activity patterns pointed to highly active compounds, which were not detected at UV/Vis/FLD but first via the biological and enzymatic assays. This effect-directed profiling bridges the gap from analytical food chemistry to food toxicology, and thus, makes an important contribution to consumer safety. In the same way, it would accelerate investigations for Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) according to Regulation (EC) No. 1907/2006.

Fatty Acid Prediction in Bovine Milk by Attenuated Total Reflection Infrared Spectroscopy after Solvent-Free Lipid Separation.

In the present study, a novel approach for mid-infrared (IR)-based prediction of bovine milk fatty acid composition is introduced. A rapid, solvent-free, two-step centrifugation method was applied in order to obtain representative milk fat fractions. IR spectra of pure milk lipids were recorded with attenuated total reflection Fourier-transform infrared (ATR-FT-IR) spectroscopy. Comparison to the IR transmission spectra of whole milk revealed a higher amount of significant spectral information for fatty acid analysis. Partial least squares (PLS) regression models were calculated to relate the IR spectra to gas chromatography/mass spectrometry (GC/MS) reference values, providing particularly good predictions for fatty acid sum parameters as well as for the following individual fatty acids: C10:0 (R2P = 0.99), C12:0 (R2P = 0.97), C14:0 (R2P = 0.88), C16:0 (R2P = 0.81), C18:0 (R2P = 0.93), and C18:1cis (R2P = 0.95). The IR wavenumber ranges for the individual regression models were optimized and validated by calculation of the PLS selectivity ratio. Based on a set of 45 milk samples, the obtained PLS figures of merit are significantly better than those reported in literature using whole milk transmission spectra and larger datasets. In this context, direct IR measurement of the milk fat fraction inherently eliminates covariation structures between fatty acids and total fat content, which poses a common problem in IR-based milk fat profiling. The combination of solvent-free lipid separation and ATR-FT-IR spectroscopy represents a novel approach for fast fatty acid prediction, with the potential for high-throughput application in routine lab operation.

Cleaving Ergot Alkaloids by Hydrazinolysis-A Promising Approach for a Sum Parameter Screening Method.

Ergot alkaloids are mycotoxins formed by fungi of the Claviceps genus, which are some of the most common contaminants of food and feed worldwide. These toxins are a structurally heterogeneous group of compounds, sharing an ergoline backbone. Six structures and their corresponding stereoisomers are typically quantified by either HPLC-FLD or HPLC-MS/MS and the values subsequently summed up to determine the total ergot alkaloid content. For the development of a screening method targeting all ergot alkaloids simultaneously, the alkaloids need to be transferred to one homogeneous structure: a lysergic acid derivative. In this study, two promising cleaving methods—acidic esterification and hydrazinolysis—are compared, using dihydroergocristine as a model compound. While the acidic esterification proved to be unsuitable, due to long reaction times and oxidation sensitivity, hydrazinolysis reached a quantitative yield in 40‒60 min. Parallel workup of several samples is possible. An increasing effect on the reaction rate by the addition of ammonium iodide was demonstrated. Application of hydrazinolysis to a major ergot alkaloid mix solution showed that all ergopeptines were cleaved, but ergometrine/-inine was barely affected. Still, hydrazinolysis is a suitable tool for the development of a sum parameter screening method for ergot alkaloids in food and feed.

Application of ATR-FTIR spectroscopy for profiling of non-structural carbohydrates in onion (Allium cepa L.) bulbs

Qualitative and quantitative composition of non-structural carbohydrates comprising glucose, fructose, sucrose and fructooligosaccharides (FOS) is one of the key determinants of market suitability, storability and technological processability of onions. To develop a cost-effective and rapid tool for carbohydrate profiling, applicability of attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy of onion juice was investigated with special regard to FOS patterns. As reference, detailed carbohydrate profiles of onion juices were generated by high-performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD).Hierarchical cluster analysis (HCA) of ATR-FTIR spectra was successfully applied for classifying onions into fresh market, storage and dehydrator type according to HPLC-ELSD profiles.A bootstrapping method for automatized test-set validation by projection to latent structures (PLS) algorithms using HPLC and ATR-FTIR spectroscopy data was developed. Model statistics showed promising perspectives for reliable quantification of individual saccharides and sum parameters. The presented methodology allows estimating the nutritional and pre-biotic value directly during cultivation and processing.

Phosphorylation of histone H2A.X as a DNA‑associated biomarker (Review)

The complex genomic structure of eukaryotic cells is primarily achieved by the binding of DNA to histones. Different members of the histone families form a complex with genomic DNA and, as a nucleosome, constitute the functional unit of chromatin. In addition to their structural functionality, histones are also involved in other molecular mechanisms, such as DNA damage recognition and repair. A very important factor of DNA damage management is the histone H2A.X. The phosphorylation of H2A.X initiates various processes of the DNA repair systems and plays significant roles in cellular regulation. The H2A.X phosphorylation status represents a central sum parameter for genome integrity and allows conclusions to be drawn about DNA‑associated processes in cells and tissues. As a biomarker for DNA damage and genotoxicity, as well as a clinical marker for radiotherapy outcome, drug efficacy and tissue regeneration, the H2A.X phosphorylation status represents an effective biomarker for current and future biomedical applications. The present brief review article provides an overview of the various molecular functions and cellular events in which the phosphorylation of histone H2A.X can occur.

Effects of Home Confinement on the Intensity of Physical Activity during the COVID-19 Outbreak in Team Handball According to Country, Gender, Competition Level, and Playing Position: A Worldwide Study.

This study investigated effects of home confinement on physical activity (PA) in Team Handball during the COVID-19 outbreak. A total of 1359 handball players participated (age: 23 ± 6 years). Participants from Europe, Western Asia, and North Africa answered an online version of the International Physical Activity Questionnaire (IPAQ) considering “before” and “during” confinement. COVID-19 home confinement has had a negative effect on PA (vigorous, moderate, walking, and overall). The largest decrease was in the sum parameter “all PA” (MET (metabolic equivalent of task)-min/week, ηp2 = 0.903; min/week, ηp2 = 0.861). Daily sitting time increased from 2.7 to 5.0 h per weekday (p < 0.001, ηp2 = 0.669). For gender, continent, country, level of handball league, and playing position, no significant differences (group and interaction effects) were observed. The largest change in PA behavior was in walking (minutes per day: ηp2 = 0.755), with males displaying the greatest decrease (from 62 ± 11 to 30 ± 14 min per weekday; d = 2.67). In terms of magnitude, difference between genders was greatest for sitting time (difference in d = 1.20). In conclusion, while COVID-19 measures were essential to preserve public health, PA was compromised and sedentary behavior increased because of these public health measures regardless of gender, playing position, and competition level.

Bottom-up effects of fungicides on tadpoles of the European common frog (Rana temporaria).

Biodiversity is under pressure worldwide, with amphibians being particularly threatened. Stressors related to human activity, such as chemicals, are contributing to this decline. It remains, however, unclear whether chemicals exhibiting a fungicidal activity could indirectly affect tadpoles that depend on microbially conditioned leaf litter as food source. The indirect effect of fungicides (sum concentration of a fungicide mixture composed of azoxystrobin, carbendazim, cyprodinil, quinoxyfen, and tebuconazole: 100 µg/L) on tadpoles was assessed relative to leaf litter colonized by microbes in absence of fungicides (control) and a worst‐case scenario, that is leached leaf litter without microbial colonization. The quality of leaf litter as food for tadpoles of the European common frog (Rana temporaria) was characterized through neutral lipid fatty acid profiles and microbial sum parameters and verified by sublethal responses in tadpoles (i.e., feeding rate, feces production, growth, and fatty acid composition). Fungicides changed the nutritious quality of leaf litter likely through alterations in leaves’ neutral lipid fatty acid profiles (i.e., changes in some physiologically important highly unsaturated fatty acids reached more than 200%) in combination with a potential adsorption onto leaves during conditioning. These changes were reflected by differences in the development of tadpoles ultimately resulting in an earlier start of metamorphosis. Our data provide a first indication that fungicides potentially affect tadpole development indirectly through bottom‐up effects. This pathway is so far not addressed in fungicide environmental risk assessment and merits further attention.

Effects of COVID-19 Lockdown on Physical Activity, Sedentary Behavior, and Satisfaction with Life in Qatar: A Preliminary Study.

This study examined the effects of home confinement on physical activity (PA) and life satisfaction during the COVID-19 outbreak in Qatar. A total of 1144 subjects participated (male: n = 588; female: n = 556; age: 33.1 ± 11.1 years; mass: 76.1 ± 16.4 kg; height: 1.70 ± 0.11 m; body mass index (BMI): 26.1 ± 4.44 kg/m2). Online survey questions considered “before” and “during” confinement. Confinement reduced all PA intensities (ηp2 = 0.27–0.67, p < 0.001) and increased daily sitting time from 3.57 ± 1.47 to 6.32 ± 1.33 h per weekday (ηp2 = 0.67, p < 0.001). The largest reduction was detected for the sum parameter all physical activity (minutes per week, ηp2 = 0.67, p < 0.001; MET (metabolic equivalent of task)-minutes/week, ηp2 = 0.69, p < 0.001). Life satisfaction decreased, with the score for “I am satisfied with my life” (ηp2 = 0.76, p < 0.001) decreasing from 28.1 ± 4.81 to 14.2 ± 6.41 arbitrary units (AU). Concerning life satisfaction, the largest change was detected for the statement “the conditions of my life are excellent” (dmale = 7.93). For all parameters, time effects were indicative of large negative effects in both genders. In terms of magnitude, the difference between gender was greatest for the parameter “the conditions of my life are excellent” (difference between groups, d = 4.84). In conclusion, COVID-19 confinement decreased PA, increased sitting time, and decreased life satisfaction in Qatar. These precautionary findings explicate the risk of psychosocial impairment and the potential physical harm of reducing physical activity during early COVID-19 confinement in 2020.

Determination of organic chlorine in water via AlCl derivatization and detection by high-resolution continuum source graphite furnace molecular absorption spectrometry.

High-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GF-MAS) was employed for determining adsorbable organic chlorine (AOCl) in water. Organic chlorine was indirectly quantified by monitoring the molecular absorption of the transient aluminum monochloride molecule (AlCl) around a wavelength of 261.42 nm in a graphite furnace. An aluminum solution was used as the molecular-forming modifier. A zirconium coated graphite furnace, as well as Sr and Ag solutions were applied as modifiers for a maximal enhancement of the absorption signal. The pyrolysis and vaporization temperatures were 600 °C and 2300 °C, respectively. Non-spectral interferences were observed with F, Br, and I at concentrations higher than 6 mg L-1, 50 mg L-1, and 100 mg L-1, respectively. Calibration curves with NaCl, 4-chlorophenol, and trichlorophenol present the same slope and dynamic range, which indicates the chlorine atom specificity of the method. This method was evaluated and validated using synthetic water samples, following the current standard DIN EN ISO 9562:2004 for the determination of the sum parameter adsorbable organic halides (AOX) for water quality. These samples contain 4-chlorophenol as the chlorinated organic standard in an inorganic chloride matrix. Prior to analysis, organic chlorine was extracted from the inorganic matrix via solid-phase extraction with a recovery rate >95%. There were no statistically significant differences observed between measured and known values and for a t-test a confidence level of 95% was achieved. The limits of detection and characteristic mass were found to be 48 and 22 pg, respectively. The calibration curve was linear in the range 0.1-2.5 ng with a correlation coefficient R2 = 0.9986.