Advanced micro-extraction techniques (SPME, HiSorb) for the determination of goat cheese whey wastewater VOCs.

HiSorb and solid-phase microextraction (SPME), two environmentally friendly micro-extraction techniques based on the same fundamental principles, were evaluated for their extraction efficiency of volatile organic compounds (VOCs) from goat cheese whey wastewater. For this purpose, a sample preparation method based on the headspace-HiSorb technique was developed and evaluated for its efficiency in terms of the amount of extracted compounds and reproducibility of results. Thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) and GC/MS analytical methods were used to perform the wastewater analysis, respectively. The experimental parameters of HiSorb were evaluated in terms of probe coating, extraction time, stirring speed, sample volume, extraction temperature and salt addition. Under optimal extraction conditions, it was observed that the use of the divinylbenzene/carbon wide range/polydimethylsiloxane (DVB/CWR/PDMS) triple coating for HiSorb and DVB/Carboxen (CAR)/PDMS for SPME, was best suited to extract a broader range of VOCs with higher peak intensities. A total of 34 VOCs were extracted and determined with the DVB/CWR/PDMS HiSorb probe, while only 23 VOCs were determined with the conventional DVB/CAR/PDMS SPME fiber. The DVB/CWR/PDMS HiSorb probe has a higher adsorbent capacity which results in a higher sensitivity for VOCs compared to the DVB/CAR/PDMS SPME fiber. Furthermore, the HiSorb technique exhibits better reproducibility, as indicated by the lower relative standard deviation (RSD) of 3.7% compared to 7.1% for SPME. Therefore, the HiSorb technique is an effective method for detecting VOCs in complex matrices, such as wastewater.

Treatment and recovery of phosphate from submerged anaerobic membrane bioreactor effluent using thermally treated biowaste and powder activated carbon.

This study presents a novel treatment system using a submerged anaerobic membrane bioreactor (SAnMBR) followed by adsorption onto thermally treated biowaste, and ending with a final treatment using powdered activated carbon (PAC). Despite limited phosphate and ammonium ion removal during SAnMBR operation, thermally treated eggshell (EGSL) and seagrass (SG) received SAnMBR effluent and enhanced phosphate recovery, achieving removal rates of 71.8-99.9% and 60.5-78.0%, respectively. The SAnMBR achieved an 85% COD removal, which was slightly reduced further by biowaste treatment. However, significant further reductions in COD to 20.2 ± 5.2 mg/L for EGSL effluent and 57.0 ± 13.3 mg/L for SG effluent were achieved with PAC. Phytotoxicity tests showed the SAnMBR effluent after PAC treatment notably improved seed growth compared to untreated wastewater. In addition, volatile organic compounds (VOCs) were significantly reduced in the system, including common wastewater contaminants such as dimethyl disulfide, dimethyl trisulfide, phenol, p-cresol, nonanal, and decanal. Fractionation analysis of the solid fraction, post-adsorption from both synthetic and domestic wastewater, indicated that for SG, 77.3%-94% of the total phosphorus (TP) was inorganically bound, while for EGSL, it ranged from 94% to 95.3%. This study represents the first attempt at a proof-of-concept for simultaneous treatment of domestic wastewater and phosphorus recovery using this integrated system.

Assessment of volatile emissions by aging books.

Indoor air quality (IAQ) has attracted a lot of attention due to its complexity and direct effect on human health. Indoor settings in libraries entail various volatile organic compounds (VOCs) linked to the aging and degradation of print material. The effect of the storage environment on paper life expectancy was investigated by targeting the VOC emissions of old and new books using headspace solid phase micro extraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) analysis. "Sniffing" of book degradation markers showed both ubiquitously and infrequently occurring VOCs. Old book "degradomics" revealed mostly alcohols (57%) and ethers (12%), whereas new books resulted mainly to ketones (40%) and aldehydes (21%). Chemometric processing of the results with principal component analysis (PCA) corroborated our initial observations and was able to discriminate the books by age into three groups: very old books (from the 1600 s to mid-1700), old books (from the 1800s to the early 1900s), and modern books (from the mid-twentieth century onwards) based on their gaseous markers. The measured mean concentrations of selected VOCs (acetic acid, furfural, benzene, and toluene) were below the respective guidelines set for similar places (i.e. museums). The applied non-invasive, green analytical methodology (HS-SPME-GC/MS) can assist librarians, stakeholders, and researchers to evaluate the IAQ, as well as the degree of degradation, and take the appropriate measures for book restoration and monitoring protocols.

Fecal Microbiota and Associated Volatile Organic Compounds Distinguishing No-Adenoma from High-Risk Colon Adenoma Adults.

Microbiota and the metabolites they produce within the large intestine interact with the host epithelia under the influence of a range of host-derived metabolic, immune, and homeostatic factors. This complex host-microbe interaction affects intestinal tumorigenesis, but established microbial or metabolite profiles predicting colorectal cancer (CRC) risk are missing. Here, we aimed to identify fecal bacteria, volatile organic compounds (VOC), and their associations that distinguish healthy (non-adenoma, NA) from CRC prone (high-risk adenoma, HRA) individuals. Analyzing fecal samples obtained from 117 participants ≥15 days past routine colonoscopy, we highlight the higher abundance of Proteobacteria and Parabacteroides distasonis, and the lower abundance of Lachnospiraceae species, Roseburia faecis, Blautia luti, Fusicatenibacter saccharivorans, Eubacterium rectale, and Phascolarctobacterium faecium in the samples of HRA individuals. Volatolomic analysis of samples from 28 participants revealed a higher concentration of five compounds in the feces of HRA individuals, isobutyric acid, methyl butyrate, methyl propionate, 2-hexanone, and 2-pentanone. We used binomial logistic regression modeling, revealing 68 and 96 fecal bacteria-VOC associations at the family and genus level, respectively, that distinguish NA from HRA endpoints. For example, isobutyric acid associations with Lachnospiraceae incertae sedis and Bacteroides genera exhibit positive and negative regression lines for NA and HRA endpoints, respectively. However, the same chemical associates with Coprococcus and Colinsella genera exhibit the reverse regression line trends. Thus, fecal microbiota and VOC profiles and their associations in NA versus HRA individuals indicate the significance of multiple levels of analysis towards the identification of testable CRC risk biomarkers.

Optimization of Carob Products Preparation for Targeted LC-MS/MS Metabolomics Analysis.

Carob (Ceratonia siliqua) is an exceptional source of significant bioactive compounds with great economic importance in the Mediterranean region, where it is widely cultivated. Carob fruit is used for the production of a variety of products and commodities such as powder, syrup, coffee, flour, cakes, and beverages. There is growing evidence of the beneficial effects of carob and the products made from it on a range of health problems. Therefore, metabolomics could be used to explore the nutrient-rich compounds of carob. Sample preparation is a crucial step in metabolomics-based analysis and has a great impact on the quality of the data obtained. Herein, sample preparation of carob syrup and powder was optimized, to enable highly efficient metabolomics-based HILIC-MS/MS analysis. Pooled powder and syrup samples were extracted under different conditions by adjusting pH, solvent type, and sample weight to solvent volume ratio (Wc/Vs). The metabolomics profiles obtained were evaluated using the established criteria of total area and number of maxima. It was observed that the Wc/Vs ratio of 1:2 resulted in the highest number of metabolites, regardless of solvent type or pH. Aqueous acetonitrile with a Wc/Vs ratio of 1:2 satisfied all established criteria for both carob syrup and powder samples. However, when the pH was adjusted, basic aqueous propanol 1:2 Wc/Vs and acidic aqueous acetonitrile 1:2 Wc/Vs provided the best results for syrup and powder, respectively. We strongly believe that the current study could support the standardization of the metabolomics sample preparation process to enable more efficient LC-MS/MS carob analysis.

Tomato waste biochar in the framework of circular economy.

Tomato pomace was slowly pyrolyzed at 350 and 550 °C (under an N2 flow of 50 L/h) at a rate of 6 °C/min and a residence time of 1:30 h to produce two biochars named B350 and B550, respectively. In addition, the two biochars were chemically activated with ΚΟΗ (at a ratio of 1:10 w/v) at 800 °C to produce two new materials named BA350 and BA550. The four biochars produced were characterized physically and chemically (pH, yield, calorific value). They were also analyzed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (B.E.T), elemental analysis (EA), and thermogravimetric analysis (TGA). The results showed that as the pyrolysis temperature increased (350 to 550 °C), the specific surface area (SSA) increased. The latter was also significantly increased by the activation process. EA showed a variation in the mineral content of the produced biochars, resulting in a different content of the biochars after activation. The parameters studied showed that biochars from tomato waste could be used as an organic amendment to improve soil fertility in agricultural. In addition, because of their ability to absorb water, they could be used as a water reservoir in soils in arid areas.

Photovoltaic-driven electrochemical remediation of drilling fluid wastewater with simultaneous hydrogen production.

In this work, we studied the application of photovoltaic solar energy for driving the electrochemical processes of electrocoagulation and electrooxidation to remediate drilling fluid wastewater, and simultaneously harvest energy in the form of electrolytic hydrogen gas produced at the cathode. The electrocoagulation was performed with sacrificial aluminium electrodes and electrooxidation with dimensionally stable boron-doped diamond electrodes in batch-wise and continuously operated mode, and their efficiency in both pollutants removal and hydrogen gas production was elucidated. The parameters affecting the efficiency of the applied electrochemical processes, such as applied current density, pH, electroprocessing time and flow rate, were investigated. The electrochemical processing was monitored by measuring the chemical oxygen demand (COD) of treated wastewater. The electrocoagulation treatment conducted with current densities of 30, 60 and 90 mA/cm2 reduced the wastewater COD by about 67%, whereas the electrooxidation treatment at the same conditions yielded a COD removal of over 95%. The amount of produced hydrogen was 171 L/g COD removed from treated wastewater.

HS-SPME-GC/MS Analysis for Revealing Carob's Ripening.

Carob's recognized nutritional and medicinal value next to its unique agriculture importance is associated with an array of social, economic, and cultural activities. The carob fruit is popular for its intense aroma due to the emitted volatile organic compounds (VOCs). The composition of VOCs released from carob fruits changes during ripening, rendering it a non-invasive tool for the determination of the ripening period and freshness of the fruit. Therefore, headspace solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS) was applied to reveal the respective gaseous signal molecules related to fruit maturity. The sampling was implemented during weeks 26-36 from five different locations in Cyprus. Additionally, the gaseous emissions of total VOCs (TVOCs) and carbon dioxide (CO2) were recorded next to the moisture content of the fruit. The major chemical classes in the ripening are acids, followed by esters, and ketones. More specifically, the most abundant VOCs during ripening are propanoic acid, 2-methyl-(isobutyric acid), 2-heptanone, propanoic acid, 2-methyl-, 2-methylbutyl ester, acetic acid, methyl isobutyrate, propanoic acid, 2-methyl-, 3-methylbutyl ester, 2-pentanone, butanoic acid and propanoic acid, 2-methyl-ethyl ester. Finally, CO2 emissions and moisture content showed a rapid decline until the 31st week and then stabilized for all examined areas. The methodology revealed variations in VOCs' profile during the ripening process.

Biogas upgrading to methane and removal of volatile organic compounds in a system of zero-valent iron and anaerobic granular sludge.

The current study presented a novel process of biogas upgrading to biomethane (higher than 97%) based on anaerobic sludge and zero-valent iron (ZVI) system. When ZVI was added into an aquatic system with anaerobic granular sludge (AnGrSl) under anaerobic abiotic conditions, H2 was generated. Then, the H2 and CO2 were converted by the hydrogenotrophic methanogens to CH4. Biogas upgrading to biomethane was achieved in 4 days in the AnGrSl system (50 g L-1 ZVI, initial pH 5 and 20 g L-1 NaHCO3). In this system, when zero-valent scrap iron (ZVSI) was added instead of ZVI, a more extended period (21 days) was required to achieve biogas upgrading. X-ray diffraction (XRD) analysis revealed that the materials in a reactor with CO2 or biogas headspace, exhibited a mixture of ferrite and the iron carbonate phase of siderite (FeCO3), with the latter being the dominant phase. VOCs analysis in raw biogas (in the system of anaerobic sludge and ZVI) highlighted the reduction of low mass straight- and branched-chain alkanes (C6-C10). Also, H2S and NH3 were found to be substantially reduced when the anaerobic sludge was exposed to ZVI compared to the cases where ZVI was not added. This study found that simultaneously with biogas upgrading, VOCs, H2S and NH3 can be removed in a system of ZVI or ZVSI and AnGrSl under aquatic anaerobic conditions.

Colon Cancer: From Epidemiology to Prevention.

Colorectal cancer (CRC) is one of the most prevalent cancers affecting humans, with a complex genetic and environmental aetiology. Unlike cancers with known environmental, heritable, or sex-linked causes, sporadic CRC is hard to foresee and has no molecular biomarkers of risk in clinical use. One in twenty CRC cases presents with an established heritable component. The remaining cases are sporadic and associated with partially obscure genetic, epigenetic, regenerative, microbiological, dietary, and lifestyle factors. To tackle this complexity, we should improve the practice of colonoscopy, which is recommended uniformly beyond a certain age, to include an assessment of biomarkers indicative of individual CRC risk. Ideally, such biomarkers will be causal to the disease and potentially modifiable upon dietary or therapeutic interventions. Multi-omics analysis, including transcriptional, epigenetic as well as metagenomic, and metabolomic profiles, are urgently required to provide data for risk analyses. The aim of this article is to provide a perspective on the multifactorial derailment of homeostasis leading to the initiation of CRC, which may be explored via multi-omics and Gut-on-Chip analysis to identify much-needed predictive biomarkers.

TD-GC/MS analysis of indoor air pollutants (VOCs, PM) in hair salons.

Hairdressing personnel is daily exposed to various chemical air pollutants, and specifically to Volatile Organic Compounds (VOCs) and Particulate Matter (PM) in hair salons. This is of concern, due to the hazardous effects of these chemicals on the individual's health. Nevertheless, a limited exposure assessment of indoor air quality (IAQ) has been performed. The aim of this study was to analyze the indoor air in 5 hair salons, to assess the IAQ of the occupational exposure, and to identify the main VOCs produced or activities responsible for the respective indoor pollution. The chemical analysis took place inside the salon environment by monitoring the emitted VOCs, as well as the PM of 1, 2.5, 4, and 10 µm aerodynamic diameter. The sampling of VOCs was performed by adsorption of pollutants on Tenax TA sorbent tubes, that were subsequently analyzed using a thermal desorption unit coupled to gas chromatography/mass spectrometry (TD-GC/MS). The obtained results showed that hair products are a major source of air pollutants, as elevated concentrations of VOCs and PM are released in the working environment. Furthermore, the type and concentration of VOCs are affected by the various hair treatment activities taking place in the salons. Among the main compounds detected there was benzene, toluene, ethylbenzene, and xylenes, known as BTEX, as well as, diethyl phthalate, 1,4-dioxane, etc. More than 50 VOCs were identified (occurrence ≥60%) and 14 of them were quantified. Their average concentration levels varied from 12 µg m-3 for naphthalene to 941 µg m-3 for toluene. The measuring levels for PM revealed violations of the EPA and WHO international standards for permissible limit concentrations; this was the case in all hair treatment activities but mostly during keratin treatment. Hence, much more effort is needed to reduce the respective concentration levels of PM and VOCs, that contribute to self-reported health problems.

Development of food-origin biochars for the adsorption of selected volatile organic compounds (VOCs) for environmental matrices.

Four novel fruit-derived biochars were developed: pomegranate peels (PB), prickly pear peels (PPB), carob (CB), and locust bean gum (LBGB). The feedstocks were pyrolyzed at 350 and 550 ℃ (under N2), respectively, and characterized using Scanning Electron Microscopy (SEM), Elemental Analysis (EA), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), Brunauer-Emmett-Teller (B.E.T) analysis, and Thermogravimetric analysis (TGA). A systematic and comprehensive comparison for the adsorption of selected volatile organic compounds (VOCs) by biochar was established. Cresol, dimethyl trisulfide (DMTS), hexane, and benzene were examined as a function of contact time (30-480 min), mass (0.1-1 g), concentration levels (50-1000 ppbv), efficiency, and reusability, using the headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) method. PB 550 ℃ revealed a specific surface area of 8.3 m2 g-1, the fastest complete removal, an ideal mass of 1 g, 3-times reuse, and âˆ¼ 99% removal of 500 ppbv benzene, cresol, DMTS, and 100 ppbv hexane.

Method validation for the determination of 314 pesticide residues using tandem MS systems (GC-MS/MS and LC-MS/MS) in raisins: Focus on risk exposure assessment and respective processing factors in real samples (a pilot survey).

A multi-residue method for the simultaneous analysis of a wide range of pesticides in raisins using liquid and gas chromatography-tandem mass spectrometry (LC-MS/MS and GC-MS/MS) has been validated. Pesticides are extracted from raisins with ethyl acetate, followed by centrifugation. The validation study was in accordance with DG SANTE guidelines. Validation experiments have been performed in both analytical instruments. A total number of 314 pesticides were spiked in raisins of organic farming at two spiking levels for GC-MS/MS (0.025 and 0.1 mg/kg), and at three spiking levels for LC-MS/MS (0.005, 0.05, and 0.1 mg/kg) with 6 replicates at each concentration. The scope of validation included linearity, limits of quantification (LOQ), accuracy, precision, and matrix effects (%) for each pesticide. The validated method was then applied for the analysis of 37 commercial raisin samples purchased from the market. For the evaluation of the results, processing factors (PFs) have been applied to derive the amount of residue in raisins, from the maximum residue levels (MRLs) of grapes, and which in this paper will be referred as to the MRL expressed in raisins. In all conventional samples, pesticides were detected at concentrations above the LOQ. In total, 55 different pesticides were detected. All conventional samples contained multiple pesticides ranging from 2 to 24. On the other hand, samples from organic farming were found to be free of the analysed pesticides. The 13.5% of the examined samples were considered as violations. The exposure assessment for the acute risk of the violating samples indicated that no potential risk derives from the detected and approved in the EU pesticides, while the detection of not approved pesticides in the EU, and the lack of toxicological reference values for certain pesticides raise concerns for the human health, especially for children. The results of the survey study indicate the need to include processed samples, and in particular dry fruits with a high consumption rate such as raisins, in the official controls of pesticide residues in food.

Oil biodesulfurization: A review of applied analytical techniques.

The wide use of fossil fuels and their associated environmental concerns, highlighted the importance of affordable and clean energy (goal 7), as adopted by the Sustainable Development Goals of the United Nations for 2030. For years now, the detection of sulfur components in liquid fuels is performed mainly for environmental and health purposes in compliance with the respective legislations. Towards this, the aerobic and anaerobic biodesulfurization (BDS) process, which entails the use of microorganisms to limit the sulfur concentration is followed. To ensure effective BDS, several traditional analytical methods are utilized, although they require bench-top, bulky, costly, and time-consuming instruments along with skilled personnel. The currently employed analytical methods are mostly chromatographic techniques (e.g. liquid and gas) coupled with various detectors. To start with, high-performance liquid chromatography with ultraviolet detector (HPLC-UV), as well as electrospray ionization-LC-mass spectrometry (ESI-LC-MS) were mostly reported. Additionally, many detectors were coupled to gas chromatography (CG) including atomic emission detector (GC-AED), flame ionization detector (GC-FID), flame photometric detector (GC-FPD), sulfur fluorescence detector (GC-SFD), mass selective detector (GC-MS), etc. The solid-phase microextraction (SPME) technique provides extra capabilities when added to the separation techniques. Towards the continuous interest in oil supercomplex synthesis, other atmospheric and surface desorption ionization techniques, as well as the multidimensional 2D chromatographic systems (GC × GC and LC × LC) were also investigated, due to their unsurpassed resolution power. The current review ends with final remarks per applied methodology and the necessity to respect and protect the human environment and life.

Use of biochar for the sorption of volatile organic compounds (VOCs) emitted from cattle manure.

The ability of biochar to be used as filter or as additive for the adsorption of volatile organic compounds (VOCs) emitted from cattle manure is investigated. The employed biochar was produced from cattle manure after slow pyrolysis at 550 °C (under nitrogen). Towards this, in-house-made glass emission reactors were filled with fresh cattle manure samples and a thin layer of biochar (10% w/w) was placed on the top of the manure layer. The mixture was left for 24 h to equilibrate and air samples were collected from the headspace air. The samples were then analyzed using the headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) method. Cattle manure emissions are considered unpleasant and odoriferous. The respective changes in the emitted cattle manure VOCs were reported; these included mainly reduction in sulfur- (thiols and sulfides) and oxygen-containing VOCs (alcohols, ketones, phenolics), showing a promising application of biochar for the removal of such compounds from manure wastes. Also, five VOCs were selected as sorbents for further laboratory studies: hexane, dimethyl trisulfide, phenol, p-cresol, and 2-methyl-3-pentanone. The results of cattle manure-derived biochar, revealed a reduction in their emitted concentrations (low ppbv). The present application highlights a straightforward example of cyclic economy, where a waste product is reused after being processed; its re-usage as odor adsorbent serves again the agriculture sector.

Native plants for the remediation of abandoned sulphide mines in Cyprus: A preliminary assessment.

Mining in Cyprus resulted in a significant number of abandoned sulphide mines without any rehabilitation measures. The present study aims to describe and compare the environmental parameters in three such mines with respect to water chemistry, waste dumps geochemistry, slope-topography and plant growth. The mines under study are that of Kokkinopezoula, North and South Mathiatis located at the northeast of the Troodos massif. A synopsis of the previous studies conducted for the above-mentioned mines is presented, which includes water and soil samples analyses. Although, in these areas environmental degradation is reported, there are some plants which grow naturally. Therefore, a preliminary attempt to report these plants is conducted, while remediation options presented in the literature including technosols, revegetation, phytoremediation and phytostabilization are proposed. Potential use of native plants such as Phragmites australis, Tamarix smyrnensis, Poaceae, Pinus brutia and Schoenus nigricans Poaceace could be applied for phytoremediation of the sulphide mines in Cyprus. These plants seem to have great strength at low pH values and high metal content in contaminated soils and water. The three mines under study are also compared with three other old mines located in the broader area of Cyprus; that of Xeros, Limni and Skouriotissa, which operated under similar climatic conditions. By improving abandoned mines environment with technosols, the action of native plants will be enhanced and thus work towards a successful phytoremediation treatment, resulting in the minimization of future pollutants generated by the solid waste dumps.

Use of Chemometrics for Correlating Carobs Nutritional Compositional Values with Geographic Origin.

Carobs unique compositional and biological synthesis enables their characterization as functional foods. In the present study, 76 samples derived from fruit and seeds of carobs, with origin from the countries of the Mediterranean region (Cyprus, Greece, Italy, Spain, Turkey, Jordan and Palestine) were analyzed for their nutritional composition, in order to identify potential markers for their provenance and address the carobs' authenticity issue. Moisture, ash, fat, proteins, sugars (fructose, glucose, sucrose), dietary fibers and minerals (Ca, K, Mg, Na, P, Cu, Fe, Mn, Zn) were estimated following official methods. Due to the large number of data (76 samples × 17 parameters × 7 countries), chemometric techniques were employed to process them and extract conclusions. The samples of different geographical origin were discriminated with 79% success in total. The carobs from Cyprus, Italy and Spain were correctly classified without error. The main discriminators were found to be the dietary fibers, the carbohydrates and Cu, Zn and Mn, which emphasize their specific nutritional added value to the product and the country of origin impact. The results suggest that the proposed analytical approach is a powerful tool that enables the discrimination of carobs based on their country of origin. This research contributes to authenticity of carobs, adding value to local products.

LC-ESI-MS/MS determination of oxyhalides (chlorate, perchlorate and bromate) in food and water samples, and chlorate on household water treatment devices along with perchlorate in plants.

The results of the validation study of the LC-ESI-MS/MS method for the determination of chlorate (ClO3-), perchlorate (ClO4-) and bromate (BrO3-) in water and food samples are summarized. Towards this, 284 samples of drinking water were analysed, out of which the 69% contained chlorate above the limit of quantitation (LOQ) of 0.01 mg/L, with maximum amount of 1.1 mg/L. Only 6 samples were found to be positive with perchlorate at levels <0.01 mg/L. Bromate was detected in 5 drinking water samples at levels above the LOQ, at concentrations up to 0.026 mg/L. For the validation of the method in food, 108 blank samples were spiked with chlorate and perchlorate for the LC-MS/MS analysis at two levels. In total 247 food samples from the market of 19 different commodities including fruits, vegetables, cereals and wine, were analysed. The maximum concentration of chlorate was found at 0.83 mg/kg in a sample of cultivated mushrooms. The number of samples contaminated with perchlorate was also small, with all the determined concentrations below the LOQ of 0.05 mg/kg. Experiments for the chlorate reduction in drinking water, showed that reverse osmosis treatment is effective in particular with newly installed cartridges. Finally, according to the results of the pilot study when chlorinated water is used for the plant irrigation, accumulation of chlorate is observed, especially in the green parts of the plant. Perchlorate was also detected in leafy samples, although it was not present in the irrigation water.

The effects of different soil nutrient management schemes in nitrogen cycling.

It is imperative for sustainable agriculture to explore practices and inputs creating low N2O emission capacity without reducing the productivity of the agricultural system. To evaluate different nutrient management schemes, a microcosm study was conducted to assess the direct N2O emission from soil. Four different treatments were used to provide a preliminary assessment of N2O emissions, as well as the concentrations of nitrates (NO3-) and ammonium (NH4+) produced in soil: compost (derived from green plant residues), chickpea residues (green manure) in two different N concentrations (2.6% and 5.5%, respectively) and ammonium nitrate (fertilizer). The soil was thoroughly mixed with the organic amendments and ammonium nitrate and incubated for 31 days. The emissions of N2O were higher in green manure with high-N content, as a source of nitrogen in the soil, and were similar to the emissions measured from the chemically fertilized soil. In particular, chickpea residues, with high-N content, exhibited cumulative N2O emissions, equal to 266.17 µg N/m2, whereas in fertilized soil the emissions were 267.10 µg N/m2. On the contrary, the incorporation of chickpea plant residues with low-N content can be an efficient way to minimize the N2O emissions at 21.63 µg N/m2. The emissions of N2O when compost was applied, remained relatively low, equal to 5.47 µg N/m2, and in comparison to soil without any treatment. Overall, a positive association between NH4+, NO3- in soil and N2O emissions were observed. However, this response was treatment depended, and the significant positive correlation between NH4+ and N2O emissions were noticed in soils treated with ammonium nitrate, chickpea residues with low N content, as well as untreated controls. On the contrary, the positive correlation observed between NO3- and N2O emissions in soils receiving compost and high N chickpea residues, suggest that the different treatments are differentially affecting the processes that are contributing to N2O emissions in agricultural soils. These findings, emphasize that the different nutrient management schemes are differentially affecting the main process contributing to N2O emissions in agricultural soils.

Correction to: Assessing the volatile profile of carob tree (Ceratonia siliqua L.).

The original publication of this paper contains an error.