Fate of pesticides during beer brewing

Human Biomonitoring of Environmental Chemicals among Elderly in Wuhan, China: Prioritizing Risks Using EPA's ToxCast Database

In line with the "healthy aging" principle, we aim to assess the exposure map and health risks of environmental chemicals in the elderly. Blood samples from 918 elderly individuals in Wuhan, China, were analyzed using the combined gas/liquid-mass spectrometry technology to detect levels of 118 environmental chemicals. Cluster analysis identified exposure profiles, while risk indexes and bioanalytical equivalence percentages were calculated using EPA's ToxCast database. The detection rates for 87 compounds exceeded 70%. DEHP, DiBP, naphthalene, phenanthrene, DnBP, pyrene, anthracene, permethrin, fluoranthene, and PFOS showed the highest concentrations. Fat-soluble pollutants varied across lifestyles. In cluster 2, which was characterized by higher concentrations of fat-soluble substances, the proportion of smokers or drinkers was higher than that of nonsmokers or nondrinkers. Pesticides emerged as the most active environmental chemicals in peroxisome proliferator-activated receptor gamma antagonist, thyroid hormone receptor (TR) antagonist, TR agonist, and androgen receptor (AR) agonist activity assays. Additionally, PAEs and polycyclic aromatic hydrocarbons played significant roles as active contaminants for the corresponding targets of AR antagonists and estrogen receptor alpha. We proposed a list of priority pollutants linked to endocrine-disrupting toxic effects in the elderly, which may provide the groundwork for further research into environmental etiology.

Understanding How Chemical Pollutants Arise and Evolve in the Brewing Supply Chain: A Scoping Review

In this study, a critical review was carried out using the Web of ScienceTM Core Collection database to analyse the scientific literature published to date to identify lines of research and future perspectives on the presence of chemical pollutants in beer brewing. Beer is one of the world's most popular drinks and the most consumed alcoholic beverage. However, a widespread challenge with potential implications for human and animal health is the presence of physical, chemical, and/or microbiological contaminants in beer. Biogenic amines, heavy metals, mycotoxins, nitrosamines, pesticides, acrylamide, phthalates, bisphenols, microplastics, and, to a lesser extent, hydrocarbons (aliphatic chlorinated and polycyclic aromatic), carbonyls, furan-derivatives, polychlorinated biphenyls, and trihalomethanes are the main chemical pollutants found during the beer brewing process. Pollution sources include raw materials, technological process steps, the brewery environment, and packaging materials. Different chemical pollutants have been found during the beer brewing process, from barley to beer. Brewing steps such as steeping, kilning, mashing, boiling, fermentation, and clarification are critical in reducing the levels of many of these pollutants. As a result, their residual levels are usually below the maximum levels allowed by international regulations. Therefore, this work was aimed at assessing how chemical pollutants appear and evolve in the brewing process, according to research developed in the last few decades.

Fate of pesticide residues in beer and its by-products

Sustainable beer production requires a comprehensive assessment of potential hazards such as pesticides in both the finished product and waste streams, as these streams can be used to create high-value by-products. This study presents the tracking of 13 fungicides (azoxystrobin, boscalid, epoxiconazole, fenpropidin, fenpropimorph, fluquiconazole, flutriafol, fluxapyroxad, kresoxym-methyl, spiroxamine, propiconazole, prothioconazole-desthio, and tebuconazole), two insecticides (chlorpyrifos-methyl and deltamethrin), one herbicide (glyphosate), and one growth regulator (mepiquat) through the beer brewing process. Field-treated rye, wheat, and barley samples containing pesticide residues were used as adjunct during brewing. Samples of the beer as well as the by-products (spent grain, spent hops, trub and spent yeast) were collected and extracted with a modified QuEChERS method for pesticide residues analysis using GC-MS/MS and LC-MS/MS. Results show that an average of 58% of pesticide residues are retrieved in the by-products with the highest fraction (53%) recovered in the spent grain, 4% in trub, 1% in spent hops, no residues detected in spent yeast and 9% in the beer. This is consistent with these nonpolar pesticides tending to remain adsorbed to the spent grain during brewing. Glyphosate and mepiquat, the most polar pesticides included in this study, showed a different behavior, with the largest fraction (>80%) being retrieved in sweet wort and transferred to the beer. Processing factors were generated for each pesticide from the adjunct to the beer and to the four by-products.

Mixed-mode chromatographic performance using nicotinic acid-functionalized chito-oligosaccharide-bonded Ti/Si hybrid monolithic capillary columns

This article describes the fabrication of porous nicotinic acid-functionalized chito-oligosaccharide-bonded titania/silica hybrid monoliths (TiO2/SiO2@ChO-N) through a co-gelation sol-gel process. A capillary monolith with a well-defined and homogeneous structure was obtained by controlling the hydrolysis speed of titanium alkoxides in a sol mixture by using glycerol and acetylacetone. As a result of the functionalization with chito-oligosaccharides (ChO)-modified nicotinic acid, the obtained stationary phase provides superior physiochemical properties, such as a cationic hydrophilic surface, porosity, and mechanical strength. Scanning electron microscope and attenuated total reflectance-infrared spectroscopy were used to characterize the functionalized monolithic columns. The produced capillary columns showed high chromatographic performance with acceptable selectivity for charged analytes as well as organic polar compounds such as nucleic bases, nucleosides, carbamate pesticides, and strobilurin fungicides. The obtained results also indicated that the functionalized ChO's amino, amide, hydroxyl, and pyridinium ring moieties served as hydrophilic electrostatic traps for charged substances, in addition to stroing π-π interaction with the carbamate pesticides and strobilurin fungicides analytes via hydrogen bonding.

Variability in the levels of fungicide residues in final beer as they are influenced by various sequences of agrochemicals used for treatment on hops

The fate of during brewing of pesticides (organic compounds and copper) from hops was determined to reveal linkages between various pesticide sequences applied in hop yards and the level of pesticides in beer. For this purpose, laboratory-scale brewing trials were carried out with conventional hops from four localities in which pest control spray programs varied. Pesticide residue analysis in samples of hopped wort, young beer, and beer was carried out by liquid chromatography in tandem with mass spectrometry (LC-MS/MS). Cu concentrations were determined using inductively coupled plasma mass spectrometry (ICP-MS). The transfer rates (%) of individual pesticides were calculated to demonstrate their ability to be transferred from hops to the brewed solutions. The pesticides exhibited different transfer rates correlating well with their log p values; however, the obtained transfer data were not related to their concentration in hops. The average transfer rates calculated for ametoctradin (15% ± 5%), mandipropamid (38% ± 4%), boscalid (48% ± 5%), and azoxystrobin (47% ± 2%) increased in good correlation with their descending log P values. On the contrary, the transfer rates of copper residues were related to residual concentrations of copper in hops and exhibited logarithmic dependency. The carryover of the sum of all pesticides in the four samples ranged from 36% to 49%, averaging 42% ± 6%. The data showed no substantial influence of various pesticide spray sequences on the percentages of overall pesticide residues carried over into beer.

Comprehensive Review on Monitoring, Behavior, and Impact of Pesticide Residues during Beer-Making

This paper reviews the impact of beer-making stages (malting, mashing, boiling, and fermentation) on the behavior of pesticide residues. The large use of pesticides on barley and hop could cause the occurrence of their residues in beer. The foremost factors influencing the stability of residues (pH, temperature, and water content) and the physical-chemical properties of pesticides (octanol-water partition coefficient, vapor pressure, and water solubility) are essential to know their final fate. Most pesticides show a decrease in the unhopped wort because they are adsorbed onto the spent grains after mashing. In addition, their concentrations decrease during boiling and fermentation. Generally, maltsters should dedicate particular attention to the residues of hydrophobic pesticides because they can remain on the malt. Contrarily, brewers should control residues of hydrophilic pesticides because they can be carried over into young beer, disturbing the quality and organoleptic properties (flavor, aroma, taste, or color) of the beer.

Residues of pesticides and veterinary drugs in diets of dairy cattle from conventional and organic farms in Austria

Modern agriculture depends highly on pesticides and pharmaceutical preparations, so controlling exposure to these substances in the feed and food chain is essential. This article presents the first study on residues of a broad spectrum of pesticides and veterinary drugs in the diets of dairy cattle. One hundred and two representative samples of the complete diets, including basal feed rations and additional fed concentrate, were collected in three Austrian provinces (Styria, Lower and Upper Austria) in 2019 and 2020. The samples were tested for >700 pesticides, veterinary drugs and related metabolites using a validated method based on liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS). In total, 16 residues (13 pesticides and three veterinary drug residues) were detected. > 90% of the diets contained pesticide residues and <10% veterinary drug residues, whereas banned pesticides were not found. The most frequent pesticide residues were fluopyram (62%), piperonyl butoxide (39%) and diethyltoluamide (35%). The following pesticides exceed the default EU maximum residue level (MRL) (10 μg kg^-1) for products exclusively used for animal feed production: Benzovindiflupyr (proportion of samples > MRLs: 1%), bixafen (2%), fluopyram (6%), ipconazole (1%) and tebuconazole (3%). Three residues (dinitrocarbanilide, monensin and nicarbazin) of veterinary drugs were identified, all below the MRLs. Over 60% of the evaluated samples contained mixtures of two to six residues/sample. Only one pesticide (diethyltoluamide) presented a significant difference among regions, with higher concentrations in Upper Austria. Brewery's spent grains were the dietary ingredient that showed the strongest correlation to pesticide residues. These findings evidence the realistic scenario of highly occurrent low doses of pesticides cocktails in the feed/food chain, which may affect the animal, human and environmental health. Since the risk assessments are based on single pesticides, the potential synergistic effect of co-occurring chemicals ("cocktail effect") requires further investigations.

Comparative analysis of mycotoxin, pesticide, and elemental content of Canarian craft and Spanish mainstream beers

The number of craft breweries and the volume of craft beer produced globally is growing exponentially. However, little is known about their differences with mainstream beers regarding mycotoxin profile, pesticide and pollutant residues and elemental composition. Given that beer is one of the most consumed beverages worldwide, it is important to shed light on its toxicological profile. In this study, samples of 23 craft beers and 19 mainstream Spanish beers were collected to perform a comparative analysis including 8 mycotoxins, 225 pesticide residues and 50 POPs, and 50 elements. Mycotoxins were not detected in craft beers, while 100% of mainstream beers presented at least one mycotoxin. In contrast, craft beers contained higher average pesticide residues than their mainstream counterparts, although significant differences were only found in Mepiquat and Metrafenone content. No persistent organic pollutants were detected in any sample. The elemental composition presented differences between the two groups both in the concentration of elements and their hierarchy. In conclusion, the toxicological profile of all beers was safe and is unlikely to constitute a hazard to consumer health. Craft beers present significant differences from their mainstream counterparts in all the dimensions explored.

Mass Spectrometric Methods for Non-Targeted Screening of Metabolites: A Future Perspective for the Identification of Unknown Compounds in Plant Extracts

Phyto products are widely used in natural products, such as medicines, cosmetics or as so-called “superfoods”. However, the exact metabolite composition of these products is still unknown, due to the time-consuming process of metabolite identification. Non-target screening by LC-HRMS/MS could be a technique to overcome these problems with its capacity to identify compounds based on their retention time, accurate mass and fragmentation pattern. In particular, the use of computational tools, such as deconvolution algorithms, retention time prediction, in silico fragmentation and sophisticated search algorithms, for comparison of spectra similarity with mass spectral databases facilitate researchers to conduct a more exhaustive profiling of metabolic contents. This review aims to provide an overview of various techniques and tools for non-target screening of phyto samples using LC-HRMS/MS.

Mixtures of mycotoxins, phytoestrogens and pesticides co-occurring in wet spent brewery grains (BSG) intended for dairy cattle feeding in Austria

Spent brewery grains (BSG) are the main by-product of beer production and are incorporated in rations of food-delivering animals, mainly dairy cows. Like other agricultural commodities, BSG can be contaminated by a broad spectrum of natural and synthetic undesirable substances, which can be hazardous to animal and human health as well as to the environment. The co-occurrence of mycotoxins, phytoestrogens, other fungal and plant secondary metabolites, along with pesticides, was investigated in 21 BSG samples collected in dairy farms in Austria. For this purpose, a validated multi-metabolite liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS) was employed. Metabolites derived from Fusarium, Aspergillus, Alternaria and pesticide residues, were ubiquitous in the samples. Zearalenone (ZEN), T-2 and HT-2 toxins were the only regulated mycotoxin detected, albeit at concentrations below the European guidance values for animal feeds. Ergot alkaloids, Penicillium-derived metabolites, and phytoestrogens had occurrence rates of 90, 48 and 29%, respectively. Penicillium metabolites presented the highest levels among the fungal compounds, indicating contamination during storage. Aflatoxins (AFs), ochratoxins and deoxynivalenol (DON) were not detected. Out of the 16 detected pesticides, two fungicides, ametoctradin (9.5%) and mandipropamid (14.3%) revealed concentrations exceeding their respective maximum residue level (MRL) (0.01 mg kg^-1) for barley in two samples. Although based on European guidance and MRL values the levels of the detected compounds probably do not pose acute risks for cattle, the impact of the long-time exposure to such mixtures of natural and synthetic toxicants on animal health and food safety are unknown and must be elucidated.

Fate and Behavior of Field-Applied Pesticides during Malting and Mashing Processes

The present work aimed to study the fate of field-applied pesticides during malting and mashing processes. Twenty-four field-collected barley samples were subject to micromalting followed by lab-scale mashing to investigate the carryover of residual pesticides from barley to malt and then from malt to sweet wort. The citrate-buffered QuEChERS sample preparation method was adapted for simultaneous determination of 57 pesticide residues in grain, malt, spent grains, and sweet wort samples using ultra-performance liquid chromatography coupled with tandem mass spectroscopy (UPLC-MS/MS). Residues of four fungicides (fenpropimorph, pyraclostrobin, tebuconazole, and trifloxystrobin) and two insecticides (chlorpyrifos and pirimiphos-methyl), frequently found in the barley samples, were investigated in detail in this study. The carryover percentages of these pesticides to malt, against the concentration of residues in barley grain, ranged from 22% for pirimiphos-methyl up to 78% for fenpropimorph. The results confirm a general rule that residues of pesticides with log P values >2 remain on the malt, but it was found that their transfer potential is more related to its individual physical-chemical properties but does not much correlate to their log P values. In the second part of the study, a noticeable carryover from malt to sweet wort was observed for pyraclostrobin, fenpropimorph, and tebuconazole residues, and these values ranged from 2 to 15%. Moreover, the analysis of pesticide residues in spent grain after mashing revealed that the spent grain samples contain on average once as much pyraclostrobin and tebuconazole residues as the original malt. It was concluded that (1) pyraclostrobin and tebuconazole residues could be incorporated into or associated with macromolecules in barley grain to form "hidden" (bound) forms, and (2) the parent compounds are subsequently released from their hidden forms during mashing.

Ultrashort-chain perfluoroalkyl substance trifluoroacetate (TFA) in beer and tea - An unintended aqueous extraction

Trifluoroacetate (TFA) is an ultrashort-chain perfluoroalkyl substance, which is ubiquitously present in the aqueous environment. Due to its high mobility, it accumulates in plant material. The study presented here shows for the first time that TFA is a widely spread contaminant in beer and tea / herbal infusions. In 104beer samples from 23countries, TFA was detected up to 51 µg/L with a median concentration of 6.1 µg/L. An indicative brewing test and a correlation approach with potassium (K) indicate that the main source of TFA in beer is most likely the applied malt. It could be proven that the impact of the applied water is negligible in terms of TFA, which was supported by the analysis of numerous tap water samples from different countries. The unintended extraction of TFA was also demonstrated for tea / herbal infusions with a median concentration of 2.4 µg/L.

Stereoselective behaviors of the fungicide triadimefon and its metabolite triadimenol during malt storage and beer brewing

The stereoselective behaviors of triadimefon (TF) and its metabolite triadimenol (TN) during barley storage and beer brewing were studied by supercritical fluid chromatography-tandem mass spectrometry to shed light on potential security risks. Matrix-matched calibration curves were constructed for barley and beer, with determination coefficients (r²) ≥ 0.9991. Average recoveries of 77.2-107.5 % and relative standard deviations within 15.0 % were observed. The degradation of the TF enantiomers during storage followed pseudo-first-order kinetics, and S-TF was degraded in preference to R-TF with the half-life ranges 18.5-36.5 d and 20.4-69.3 d, respectively. During beer brewing, the TF enantiomers (enantiomer fraction, 0.44-0.56) were selectively metabolized into TN stereoisomers (diastereomer fraction, 0.43-0.58). The total pesticide content of beer was 93.3 % lower than that of raw grain, whereby the TF content declined by up to 100 % and the TN stereoisomers were reduced by 35.1 %. The processing factors of all the brewing steps were less than one, illustrating that beer consumption is safer after its commercial processing. Furthermore, the TF enantiomers showed different behaviors upon fermentation by two yeast strains. Thus, this work is a useful reference for assessing the food safety risk posed by individual pesticide enantiomers and their contribution to environmental pollution.

Effect of pesticide residues on simulated beer brewing and its inhibition elimination by pesticide-degrading enzyme

Four different pesticide residues used in barley planting were selected to investigate their effects on simulated beer brewing. The influences were found to be different by varied agricultural chemicals. Among the four types of pesticides, at 25 μg/mL, triadimefon or carbendazim barely affected the brewing progress. However, ethametsulfuron-methyl and carbaryl (15 μg/mL and 2.5 μg/mL, respectively) exhibited slightly inhibition on saccharification and significantly negative impacts on yeast growth and alcohol fermentation. After pretreated by 50 μL carbaryl-degrading enzyme with the K_cat value of 2.12 s^-1 at 30°C for 90 min, the negative influence on simulated beer brewing brought by carbaryl can be eliminated in the fermentation system containing 2.5 μg/mL carbaryl. The efficiency of ethanol fermentation was improved, and the removal rate of carbaryl in the brewing system was greatly accelerated. Taken together, this study suggested a potential method for solving the fermentation inhibition by pesticide residues.

Recent Trends in the Analysis of Chemical Contaminants in Beverages

Chemical contaminants should not be present in beverages for human consumption, but could eventually be ingested by consumers as they may appear naturally from the environment or be produced by anthropogenic sources. These contaminants could belong to many different chemical sources, including heavy metals, amines, bisphenols, phthalates, pesticides, perfluorinated compounds, inks, ethyl carbamate, and others. It is well known that these hazardous chemicals in beverages can represent a severe threat by the potential risk of generating diseases to humans if no strict quality control is applied during beverages processing. This review compiles the most updated knowledge of the presence of potential contaminants in various types of beverages (both alcoholic and non-alcoholic), as well as in their containers, to prevent undesired migration. Special attention is given to the extraction and pre-concentration techniques applied to these samples, as well as to the analytical techniques necessary for the determination of chemicals with a potential contaminant effect. Finally, an overview of the current legislation is carried out, as well as future trends of research in this field.

Correlates of organochlorine pesticide plasma concentrations among reproductive-aged black women

BACKGROUND

Organochlorine pesticides (OCPs) are lipophilic persistent organic pollutants associated with adverse health outcomes. Black women have higher body burdens compared with other U.S. populations and research on their correlates is limited.

METHODS

Using baseline data from a prospective cohort study of Black women aged 23-35 years from the Detroit, Michigan metropolitan area (enrolled 2010-2012), we examined correlates of plasma concentrations of the following OCPs: dichlorodiphenyltrichloroethane (p,p'-DDE), hexachlorobenzene (HCB), oxychlordane, and trans-nonachlor. At enrollment, we collected non-fasting blood samples from 742 participants. We also collected data on demographic, behavioral, dietary, occupational, and medical history factors via self-administered questionnaires, telephone interviews, and in-person clinic visits. We fit linear regression models to calculate percent (%) differences across categories of each correlate and 95% confidence intervals (CIs).

RESULTS

In models adjusted for all other correlates, a 5-year increase in age was associated with 24% higher oxychlordane (95% CI: 12%, 38%) and 26% higher trans-nonachlor (95% CI: 12%, 42%) plasma concentrations. Heavy alcohol use was associated with 7-9% higher plasma concentrations of p,p'-DDE, oxychlordane, and trans-nonachlor. Current smoking was associated with 10-19% higher plasma concentrations of all four OCPs, and was highest for current smokers of ≥10 cigarettes/day (% differences ranged from 22 to 29%). Compared with having never been breastfed during infancy, having been breastfed for ≥3 months was associated with 15% higher concentrations of p,p'-DDE (95% CI: 6%, 25%), 14% higher oxychlordane (95% CI: 5%, 24%), and 15% higher trans-nonachlor (95% CI: 5%, 27%). Consumption of ≥5 vs. ≤2 glasses/day of tap or bottled water was associated with 8-15% higher plasma concentrations of all four OCPs, and was highest for trans-nonachlor (% difference: 15%; 95% CI: 6%, 26%). No other dietary predictors were appreciably associated with plasma OCP concentrations. Obesity, parity, higher birth order, and longer lactation duration were inversely associated with plasma OCP concentrations.

CONCLUSIONS

In Black U.S. women of reproductive age, older age was an important correlate of plasma OCP concentrations. Exposure to OCPs earlier in life appears to contribute to current blood concentrations. In addition, tobacco, alcohol, and drinking water may be important sources of exposure.

A simple, fast and easy methodology for the monitoring of plastic migrants in alcoholic and non-alcoholic beverages using the QuEChERS method prior to gas chromatography tandem mass spectrometry

In this work, the development of a simple, fast and reliable method for the evaluation of a group of twelve plastic migrants in alcoholic and non-alcoholic beverages widely consumed by the population has been carried out. For that, a modified QuEChERS method for the extraction and preconcentration of the target compounds has been used prior to their separation and quantification by gas chromatography coupled to triple quadrupole tandem mass spectrometry. The whole methodology was validated for beer, cider and grape juice matrices, using dibutyl phthalate-3,4,5,6-d₄ as surrogate. Recovery ranged from 75 to 120% for all matrices with relative standard deviation values lower than 20%, and the limits of quantification of the method were achieved in the range 0.034-1.415 μg/L. Finally, the analysis of different beer, cider and grape juice samples commercialised in different supermarkets of Tenerife was carried out, finding the presence of four of the evaluated phthalates in the range 0.14-1.1 μg/L in some of the evaluated beers, six of them in several cider samples, in the range 0.3-2.1 μg/L, and one in the range 1.2-1.5 μg/L in three of the analysed grape juices.

A review of the analytical methods used for beer ingredient and finished product analysis and quality control

Beer is an incredibly complex beverage containing more than 3000 different compounds, including carbohydrates, proteins, ions, microbes, organic acids, and polyphenols, among others. Beer becomes even more complex during storage, for over time it may undergo chemical changes that negatively affect the flavor, aroma, and appearance. Thus, it can be expected that maintaining the quality of beer throughout its lifetime is a difficult task. Since it is such a popular drink throughout the world, being familiar with proper analytical techniques for beer evaluation is useful for researchers and brewers. These techniques include, but are not limited to, gas chromatography, liquid chromatography, matrix assisted laser desorption/ionization, capillary electrophoresis, mass spectrometry, ultraviolet-visible spectroscopy, and flame ionization detection. This review aims to summarize the various ingredients and components of beer, discuss how they affect the finished product, and present some of the analytical methods used for quality control and understanding the formation of chemicals in beer during the brewing process.

Tracking, Behavior and Fate of 58 Pesticides Originated from Hops during Beer Brewing

The study presents tracking of 58 pesticide residues associated with hops to estimate their carryover into brewed beer. The pesticides were spiked onto organic hops at a concentration of 15 mg/kg, and the wort was boiled with the artificially contaminated hops and fermented on a laboratory scale. Samples were collected during the whole brewing process and pesticide residues were extracted using a method known as QuEChERS (quick, easy, cheap, effective, rugged, and safe). An HPLC-HR-MS/MS method was developed and validated to identify and quantitate pesticide residues in treated hops, spent hops, hopped wort, green beer, and beer samples. Quantitation was achieved using standard addition with isotopically labeled standards. The carryover percentages into hopped wort and the percentages of decay reduction relative to the amount spiked on hops were calculated. The relationship between the partition coefficients n-octanol-water (log P values) and the residual ratios ( R_W and R_B) of a pesticide were evaluated to predict their behavior during hopping of wort and fermentation. Pesticides with a high log P values (>3.75) tended to remain in spent hops. The pesticides that have a low log P value up to approximately 3 could represent the demarcation lines of appreciable transfer rate of pesticides from hops to beer. Consequently, the pesticides were divided into three categories depending upon their fate during the brewing process. The most potential risk category represents a group involving the thermostable pesticides, such as azoxystrobin, boscalid, dimethomorph, flonicamid, imidacloprid, mandipropamid, myclobutanil, and thiamethoxam, which were transferred at high rates from the pesticide enriched hops into beer during the laboratory brewing trial. These results can be used as a guideline in the application of pesticides on hop plants that would reduce the level of pesticide residues in beer and their exposure in humans.

Occurrence of glyphosate in beer from the Latvian market

A sensitive LC-MS/MS method for the determination of glyphosate in beer has been developed, validated, and applied to analyse 100 beer samples from 24 different producers and distributors in Latvia. The selected samples represented most beer brands and varieties sold in local supermarkets. Different procedures for sample preparation and chromatographic separation were compared. The final version of the method consisted of solid phase extraction, chromatographic separation on aminopropyl stationary phase, and detection using tandem mass spectrometry. The concentration of glyphosate in beer varied from below the LOD of 0.2 μg kg-1 up to 150 μg kg-1, higher than previously reported. Significantly higher (p < 0.01) content of glyphosate was observed in beers that did not have the country of production disclosed on the label and were sold in local supermarkets by distributors from Latvia (1.8 μg kg-1 median concentration in locally produced beer, 6.7 μg kg-1 in beer of undisclosed origin).

Residue behavior and risk assessment of thifluzamide in the maize field ecosystem

In the present work, the dissipation kinetics and final residue levels of thifluzamide in the maize field ecosystem were investigated. Using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction combined with liquid chromatography-tandem mass spectrometric detection (LC-MS/MS), a rapid, sensitive, efficient, and reliable method for extraction and quantitative analysis of thifluzamide residues in maize grain, maize plant, and soil was developed. Satisfactory recoveries of 78.7-97.0% were achieved with relative standard deviations (RSDs) in the range of 1.6 to 8.2%. The limits of detection (LODs) and the limit of quantification (LOQ) were 0.002-0.005 and 0.010 mg kg^-1, respectively. The dissipation kinetics of thifluzamide in maize plant was well fitted by the first-order kinetic model with short half-lives of 0.19-0.22 days, while thifluzamide degraded slowly in soil with half-lives of 4.56-15.85 days. The final residues in maize grain, maize plant, and soil samples collected at the milk stage and the physiological maturity stage were no more than 0.010, 0.807, and 0.278 mg kg^-1, respectively. Given that no maximum residue limit (MRL) for thifluzamide in maize has been established, the safety of this fungicide application was estimated by a dietary risk assessment. The hazard quotient was 0.03%, which was substantially less than 1, indicating that the long-term risk induced by the thifluzamide application on maize at the recommended dose is negligible. These results help governments to develop regulations for the safe use of thifluzamide.

Dissipation and Residue Level of Thifluzamide in Rice Field Ecosystem

An efficient modified QuEChERS method combined with high performance liquid chromatography-tandem mass spectrometry detection (HPLC-MS/MS) was established and evaluated for the residue analysis of thifluzamide in rice grain, husk, straw, seedling, paddy water, and soil. Thifluzamide residues were extracted with acetonitrile, cleaned up with primary secondary amine (PSA), and then determined by HPLC-MS/MS. The fortified recoveries were 76%–106% with RSDs of 3%–13%. The results of the supervised field trials at two experiment sites showed that thifluzamide dissipated rapidly in paddy fields, and the half-lives in paddy water, soil, and rice seedling were 0.3–0.6 d, 1.8–3.6 d, and 4.3–13.9 d, respectively. At harvest time, when the preharvest interval (PHI) was set as 21 d, the final residues of thifluzamide in rice grains were below the maximum residue limit (MRL) of 0.5 mg/kg set by Japan, whereas the final residues in rice husk and straw were still high (the highest value reached 1.36 mg/kg in rice husk and 0.83 mg/kg in rice straw). The results indicated that the highest residue in rice grain was 0.23 mg/kg when PHI was 21 d, and only 6.9–11.0% of acute risk quotient of thifluzamide was occupied by the dietary daily intake in Chinese population consuming rice.