Comparison of data processing strategies using commercial vs. open-source software in GC-Orbitrap-HRMS untargeted metabolomics analysis for food authentication: thyme geographical differentiation and marker identification as a case study.

Untargeted analysis of gas chromatography-high-resolution mass spectrometry (GC-HRMS) data is a key and time-consuming challenge for identifying metabolite markers in food authentication applications. Few studies have been performed to evaluate the capability of untargeted data processing tools for feature extraction, metabolite annotation, and marker selection from untargeted GC-HRMS data since most of them are focused on liquid chromatography (LC) analysis. In this framework, this study provides a comprehensive evaluation of data analysis tools for GC-Orbitrap-HRMS plant metabolomics data, including the open-source MS-DIAL software and commercial Compound Discoverer™ software (designed for Orbitrap data processing), applied for the geographical discrimination and search for thyme markers (Spanish vs. Polish differentiation) as the case study. Both approaches showed that the feature detection process is highly affected by unknown metabolites (Levels 4-5 of identification confidence), background signals, and duplicate features that must be carefully assessed before further multivariate data analysis for reliable putative identification of markers. As a result, Compound Discoverer™ and MS-DIAL putatively annotated 52 and 115 compounds at Level 2, respectively. Further multivariate data analysis allowed the identification of differential compounds, showing that the putative identification of markers, especially in challenging untargeted analysis, heavily depends on the data processing parameters, including available databases used during compound annotation. Overall, this method comparison pointed out both approaches as good options for untargeted analysis of GC-Orbitrap-HRMS data, and it is presented as a useful guide for users to implement these data processing approaches in food authenticity applications depending on their availability.

Critical evaluation of MS acquisition conditions and identification process in LC-Q-Orbitrap-MS for non-targeted analysis: pesticide residues as case of study.

In routine measurements, the length of analysis time and the number of samples analysed during a given time unit are crucial. Additionally, the analytical method used has to provide reliable results and be able to identify and quantify any compound present in the matrix. High-resolution equipment, including Orbitrap analysers, is commonly used for non-targeted determinations. However, researchers still rely on trial and error to achieve the best acquisition conditions on the mass spectrometer, which is a tedious and time-consuming process that can lead to errors. Moreover, tentative compound identification, particularly when using a non-targeted approach, heavily depends on commercial databases. All of these issues can ultimately result in incomplete identification of compounds in the study matrix. In this framework, the study presented here has a dual objective: to use the experimental design tool to optimise critical parameters in mass spectrometry using LC-Q-Orbitrap-MS equipment when working in a non-targeted approach and to compare the mzCloud™ and ChemSpider™ commercial databases included in Compound Discoverer software with TraceFinder home-made databases generated to evaluate the ability to identify compounds. The study's noteworthy findings reveal that employing an experimental design has facilitated rapid optimisation of the mass spectrometer's multiplexing and loop parameters. Furthermore, the study highlights that the lack of harmonisation in commercial databases poses a disadvantage in the identification of compounds, leading to superior results when using home-made databases. In the latter databases, around 80% of the compounds were identified, which is approximately twice the number identified in commercial databases (around 40% in the best case with ChemSpider™).

Grain Germination Changes the Profile of Phenolic Compounds and Benzoxazinoids in Wheat: A Study on Hard and Soft Cultivars.

Pre-harvest sprouting is a frequent problem for wheat culture that can be simulated by laboratory-based germination. Despite reducing baking properties, wheat sprouting has been shown to increase the bioavailability of some nutrients. It was investigated whether wheat cultivars bearing distinct grain texture characteristics (BRS Guaraim, soft vs. BRS Marcante, hard texture) would have different behavior in terms of the changes in phytochemical compounds during germination. Using LC-Q-TOF-MS, higher contents of benzoxazinoids and flavonoids were found in the hard cultivar than in the soft one. Free phytochemicals, mainly benzoxazinoids, increased during germination in both cultivars. Before germination, soft and hard cultivars had a similar profile of matrix-bound phytochemicals, but during germination, these compounds have been shown to decrease only in the hard-texture cultivar, due to decreased levels of phenolic acids (trans-ferulic acid) and flavonoids (apigenin) that were bound to the cell wall through ester-type bonds. These findings confirm the hypothesis that hard and soft wheat cultivars have distinct behavior during germination concerning the changes in phytochemical compounds, namely the matrix-bound compounds. In addition, germination has been shown to remarkably increase the content of benzoxazinoids and the antioxidant capacity, which could bring a health-beneficial appeal for pre-harvested sprouted grains.

Persistent organic pollutants (PCBs and PCDD/Fs), PAHs, and plasticizers in spices, herbs, and tea - A review of chromatographic methods from the last decade (2010-2020).

Edible and highly demanded plant-derived products such as herbs, spices, and tea may be subjected to exogenous contamination of well-known chemical hazards such as persistent organic pollutants (POPs), and emerging ones such as plasticizers, affecting negatively the safety of these food commodities. This fact has led to the increasing analysis of exogenous compounds including priority POPs such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs), as well as highly persistent polycyclic aromatic hydrocarbons (PAHs). Currently, plasticizer residues are also considered an emerging issue because of the extensive use in food packaging and potential migration into foodstuffs. In this review, the studies published from 2010 to 2020 were discussed, including the main extraction methods applied for these contaminants from herbs, spices, and tea, and it was revealed the trend toward the use of less solvent-consuming and time-effective methods. Chromatographic methods were also described, which were mainly combined with detection techniques such as classical or mass spectrometry (MS) detection. Finally, a comprehensive overview of the occurrence of these selected exogenous compounds was presented in the studied matrices, showing that their monitoring should be further investigated to ensure food safety of highly consumed condiments and tea.

Characterization of the composition of plant protection products in different formulation types employing suspect screening and unknown approaches.

BACKGROUND: Plant protection products (PPPs) are used extensively in agriculture to control crops. These PPPs, which may be found in different types of formulations, are composed of a designated pesticide (active principle) and other inactive ingredients as co-formulants. They perform specific functions in the formulation, as solvents, preservatives or antifreeze agents, among others. RESULTS: A research technique based on ultra-high-performance liquid chromatography (UHPLC) coupled to a Quadrupole-Orbitrap mass analyzer was successfully applied to characterize the composition of six different PPPs in terms of the presence of co-formulants and types of formulations: emulsifiable concentrate (EC), emulsion in water (EW), suspension concentrate and water-dispersible granule. These PPPs (FLINT MAX, MASSOCUR 12.5 EC, IMPACT EVO, TOPAS, LATINO and IMPALA STAR) had antifungal activity, containing one triazole compound as active principle (tebuconazole, penconazole, myclobutanil, flutriafol or fenbuconazole, respectively). Non-targeted approaches, applying suspect and unknown analysis, were carried out and ten compounds were identified as potential co-formulants. Six (glyceryl monostearate, 1-monopalmitin, dimethyl sulfoxide, N,N-dimethyldecanamide, hexaethylene glycol and 1,2-benzisothiazol-3(2H)-one) were confirmed by injecting analytical standards. Finally, these compounds were quantified in the PPPs. CONCLUSION: The current study allowed for detecting co-formulants in a wide range of concentrations, between 0.04 (dimethyl sulfoxide) and 19.00 g L-1 (glyceryl monostearate), highlighting the feasibility of the proposed analytical methodology. Moreover, notable differences among the types of formulations of PPPs were achieved, revealing that EC and EW were the formulations that contained the largest number of co-formulants (four out of six detected compounds). © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Applicability of high-resolution NMR in combination with chemometrics for the compositional analysis and quality control of spices and plant-derived condiments.

Over the last years, the consumption of spices and plant-derived condiments has increased considerably, owing to new culinary trends. Unfortunately, the current marketing channels make them highly vulnerable to adulteration and food fraud. High-resolution nuclear magnetic resonance (NMR) is a powerful tool for the compositional study of spices and plant-derived condiments. It allows the chemical characterization of a wide range of polar and non-polar metabolites, and provides unique structural information not available by other techniques. The chemometric-based analysis of NMR 'fingerprints' has been used to discriminate samples according to species and geographical origin and to detect adulterations, among other applications. The comprehensive identification and quantification of marker compounds can be achieved even in complex mixtures, demonstrating a great potential for high-throughtput quality control applications. © 2020 Society of Chemical Industry.

Identification of adjuvants in plant protection products applying a suspect screening workflow based on orthogonal techniques.

In this study, the identification of adjuvants (surfactants and solvents) in quizalofop-p-ethyl plant protection products (PPPs) was carried out by applying nuclear magnetic resonance (NMR), ultra-high-performance liquid chromatography (UHPLC) and gas chromatography (GC), both coupled to high-resolution mass spectrometry (HRMS), and using a suspect analysis approach. NMR provided a rapid and global overview of the composition of the studied samples and supported the tentative identification of the glycol ether family, commonly employed as surfactants, and 2-ethyl-1-butanol. UHPLC-HRMS was used for characterization of the glycol polymer surfactants, while GC-HRMS was used to obtain information about volatile organic compounds (benzene or naphthalene derivates) present in the PPPs. A total of nine adjuvants were characterized in the tested PPPs, belonging to naphthalene, benzene, sulphate and fatty acid esters of glycerol families. In addition, the estimation of compound concentrations was carried out using GC(LC)-HRMS, and finally, these concentration levels were related to their toxicity values.

Dissipation kinetics of fenamidone, propamocarb and their metabolites in ambient soil and water samples and unknown screening of metabolites.

A fenamidone and propamocarb dissipation study was carried out applying ultra high-performance liquid chromatography coupled to Orbitrap mass spectrometry (UHPLC-Orbitrap-MS). Dissipation kinetics were evaluated in different types of soils and in water under different conditions (sunlight or darkness). In addition, a plant protection product containing both compounds was applied at two doses: (i) single and (ii) double dose in soils, and (i) single and (ii) fivefold dose in water. The fenamidone and propamocarb concentration decreased during the monitored period (100 days), obtaining high persistence in the case of water studies (DT50 > 50 days) and low to medium persistence in soils (DT50 < 50 days). No Observed Effect Concentration (NOEC) and concentration causing 50% lethality (EC50) were calculated and showed that fenamidone could cause toxic effects in soil and water organisms due to very high NOEC values (0.013 mg/L for aquatic invertebrates) while propamocarb did not cause any lethality. Fenamidone and propamocarb metabolites were also monitored with acetophenone and RPA-411639 ((5)-5-methyl-2-(methylthio)-3-(4-S nitrophenyl)amino-5-phenyl-3,5-dihydro-4H-imidazole-4-one) being the main metabolites for fenamidone. These metabolites obtained concentration values of up to 25% initial fenamidone content which can be a risk for the environment and fauna but, despite the toxicity of these compounds, they have not been studied yet. Metabolite 175 m/z and propamocarb n-desmethyl were the main propamocarb metabolites with values of 3% of initial propamocarb content. Three new propamocarb metabolites were detected in water samples and one in soil, highlighting the capabilities of the proposed methodology for monitoring known metabolites and identifying new ones in environmental studies.

Dissipation and residue determination of fluopyram and its metabolites in greenhouse crops.

BACKGROUND: Fluopyram is a pesticide widely used in tomato and cucumber crops cultivation to control fungal diseases that develop especially in environments with moderate temperatures and high humidity, such as in a greenhouse. The pathway of fluopyram dissipation has been monitored in cucumber and cherry tomato under greenhouse conditions. RESULTS: In the greenhouse trials, cherry tomato and cucumber were treated by irrigation water with the commercial product at the manufacturer's recommended dose and double dose. High-resolution mass spectrometry (HRMS) coupled to ultra-high-performance liquid chromatography (UHPLC) has been selected as the technique to obtain the identification of fluopyram and metabolites. The fate of fluopyram in greenhouse tomato and cucumber was investigated over 44 days. The metabolic pathway of fluopyram was: in a first step there was a primary transformation to fluopyram-7-hydroxy and fluopyram-8-hydroxy, isomeric compounds, and in a second phase to fluopyram-benzamide and fluopyram-pyridyl-carboxylic acid. The behavior of fluopyram does not fit any type of kinetic classical model of degradation. CONCLUSIONS: Greenhouse trials revealed that the fluopyram is a very persistent compound, and their terminal residues do not exceed maximum residue level (MRL) at the end of the study. © 2020 Society of Chemical Industry.

Dissipation studies of famoxadone in vegetables under greenhouse conditions using liquid chromatography coupled to high-resolution mass spectrometry: putative elucidation of a new metabolite.

BACKGROUND: Famoxadone is a pesticide that is used to control fungal diseases and its dissipation in vegetables should be monitored. For that purpose, liquid chromatography coupled to mass spectrometry has been used. RESULTS: The dissipation of famoxadone has been monitored in cucumber, cherry tomato and courgette under greenhouse conditions at different doses (single and double), using ultra high-performance liquid chromatography coupled to Orbitrap mass spectrometry (Thermo Fisher Scientific, Bremen, Germany). The concentration of famoxadone increased slightly just after the application of the commercial product and then decreased. The half-lives (DT50 ) of famoxadone are different for each matrix, ranging from 2 days (courgette single dose) to 10 days (cucumber double dose). The main metabolites, 4-phenoxybenzoic acid and 1-acetyl-2-phenylhydrazine, were not detected in vegetable samples. Other metabolites described by the European Food and Safety Authority, such as IN-JS940 [(2RS)-2-hydroxy-2-(4-phenoxyphenyl)propanoic acid], IN-KF015 [(5RS)-5-methyl-5-(4-phenoxyphenyl)-1,3-oxazolidine-2,4-dione] and IN-MN467 [(5RS)-5-methyl-3-[(2-nitrophenyl)amino]-5-(4-phenoxyphenyl)-1,3-oxazolidine-2,4-dione], were detected in the three matrices. Untargeted analysis allowed for the putative elucidation of a new metabolite of famoxadone in cucumber (up to 290 µg kg-1 ) and cherry tomato (up to 900 µg kg-1 ) samples. CONCLUSION: The dissipation of famoxadone has been investigated in three vegetables: tomato, cucumber and courgette. The persistence of famoxadone was low in the three matrices (DT50 less than 10 days). Metabolites of famoxadone were monitored, detecting IN-JS940, IN-MN467 and IN-KF015, and the putative elucidation of a new metabolite of famoxadone was performed by applying software tools. © 2019 Society of Chemical Industry.

Pushing the frontiers: boron-11 NMR as a method for quantitative boron analysis and its application to determine boric acid in commercial biocides.

Quantitative boron-11 NMR (11B qNMR) spectroscopy has been introduced for the first time as a method to determine boric acid content in commercial biocides. Validation of the method affords a limit of detection of 0.02% w/w and a limit of quantification of 0.04% w/w, which are low enough to determine boric acid in commercial biocides. Other figures of merit such as linearity (R2 > 0.99), recovery (93.6%-106.2%), intra- and inter-day precision (from 0.7 to 2.0%), uncertainty (3.7 to 4.4%) and matrix effects were also evaluated. This method was successfully applied to determine boric acid in five different commercial biocides in a wide range of concentrations (<0.05 to 10% w/w) providing excellent results when they were compared with those obtained using inductively coupled plasma-mass spectrometry (ICP-MS). The suitability of this method for a fast and reliable quantification of boric acid in commercial biocide preparations has been demonstrated. The absence of the matrix effect allows the application of this validated method for the determination of boric acid in other matrices of diverse composition.

Simultaneous analysis of tropane alkaloids in teas and herbal teas by liquid chromatography coupled to high-resolution mass spectrometry (Orbitrap).

A new method has been developed for the simultaneous determination of 13 tropane alkaloids in tea and herbal teas using high-performance liquid chromatography coupled to an Exactive-Orbitrap analyzer. A mixture of methanol, water, and formic acid was used for the extraction of the target compounds followed by a solid-phase extraction step. The validated method provided recoveries from 75 to 128% with intra- and interday precision lower than or equal to 24% (except for apoatropine). Limits of quantification ranged from 5 to 20 µg/kg. Eleven tea and herbal tea samples and two contaminated samples with Datura stramonium seeds were analyzed. Tropane alkaloids were detected in six samples with concentrations from 5 (apoatropine) to 4340 µg/kg (sum of physoperuvine, pseudotropine, and tropine), whereas concentrations from 5 (apoatropine) to 1725 µg/kg (sum of physoperuvine, pseudotropine, and tropine) were found in the contaminated samples.

Behavior of quizalofop-p and its commercial products in water by liquid chromatography coupled to high resolution mass spectrometry.

A degradation study of quizalofop-p and its commercial products (quizalofop-p-ethyl, quizalofop-p-tefuryl and propaquizafop) in water samples has been performed using ultra high-performance liquid chromatography coupled to Orbitrap mass spectrometry (UHPLC-Orbitrap-MS). CHHQ (dihydroxychloroquinoxalin), CHQ (6-chloroquinoxalin-2-ol) and PPA ((R)-2-(4-hydroxyphenoxy)propionicacid) were the main metabolites of this active substance (quizalofop-p) in water. The degradation of the parent compound has been monitored in distilled water. Several commercial products (Panarex®, Master-D® and Dixon®) were used to evaluate the degradation of the target compounds into their metabolites. The concentration of the main active substances (quizalofop-p-tefuryl, quizalofop-p-ethyl and propaquizafop) decreased during the degradation studies, whereas the concentration of quizalofop-p increased. DT50 of the main active substances ranged from 10 days to 70 days for most of the analytes, so it can be concluded that compounds are medium-high persistent in this matrix. Metabolites, such as PPA, CHHQ and CHQ, were detected in water samples after 7 days of the application of the commercial products at concentrations higher than their limits of quantification (> 0.1 µg/L). CHQ was detected at 1400 µg/L after 75 days of the application of quizalofop-p-ethyl commercial product. CHHQ and CHQ were found at the highest concentrations at 7-45 days after the application of quizalofop-p-tefuryl, whereas PPA was detected at higher concentrations (up to 5.37 µg/L) in propaquizafop samples.

Identification and quantification of phenolic compounds in edible wild leafy vegetables by UHPLC/Orbitrap-MS.

BACKGROUND: A recent interest in edible wild leafy vegetables has been documented. Consumers often associate these species with health promotion. In this study, several wild species of the Asteraceae family and Knautia integrifolia (Dipsacaceae) were locally documented for their use in traditional cuisine and sampled from the wild. RESULTS: Phenolic compounds were identified and quantified by ultra-high-performance liquid chromatography coupled to Orbitrap high-resolution mass spectrometry. Hydroxycinnamic acids ranging from 1388 to 53 076 mg kg-1 dry weight (DW) were the most abundant compounds in all species (69-98% of the total phenolic content) except Tragopogon pratensis. Thirty compounds were identified as flavonoids, mostly as glycosidic forms of luteolin, apigenin, kaempferol and quercetin. The sum of flavonoids ranged between 212 and 12 598 mg kg-1 DW; they represented 65% of the total phenolic content for T. pratensis. Three anthocyanins were detected, representing in most cases less than 1% of the total phenolic content (3-627 mg kg-1 DW). Higher anthocyanin contents were observed for Cichorium types. CONCLUSION: Different phenolic profiles were observed between species, especially considering the class of flavonoids. Individual species may be of some interest for their content of specific minor flavonoids. © 2017 Society of Chemical Industry.

Fast determination of four polar contaminants in soy nutraceutical products by liquid chromatography coupled to tandem mass spectrometry.

An analytical method based on a modified QuPPe (quick polar pesticide) extraction procedure coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was evaluated for the determination of four polar compounds (chlorate, fosetyl-Al, maleic hydrazide, and perchlorate) in nutraceutical products obtained from soy. Experimental conditions including extraction such as solvent, acidification, time, and clean-up sorbents were varied. Acidified acetonitrile (1 % formic acid, v/v) was used as extraction solvent instead of methanol (conventional QuPPe), which provides a doughy mixture which cannot be injected into the LC. Clean-up or derivatization steps were avoided. For analysis, several stationary phases were evaluated and Hypercarb (porous graphitic carbon) provided the best results. The optimized method was validated and recoveries ranged between 46 and 119 %, and correction factors can be used for quantification purposes bearing in mind that inter-day precision was equal to or lower than 17 %. Limits of quantification (LOQs) ranged from 4 to 100 µg kg-1. Soy-based nutraceutical products were analyzed and chlorate was detected in five samples at concentrations between 63 and 1642 µg kg-1. Graphical Abstract Analysis of polar compounds in soy-based nutraceutical products.

Determination of several families of phytochemicals in different pre-cooked convenience vegetables: effect of lifetime and cooking.

Phytochemicals content, including several families such as phenolic acids, isoflavones, flavones, flavonols, isothiocyanates, and glucosinolates, was determined in pre-cooked convenience vegetables by ultra high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). It was observed that there is not a common behavior of the individual concentration of phytochemicals during the lifetime and cooking of the matrix, and compounds change their concentration without a specific trend. It was observed that neither lifetime nor cooking process have significant effects on the total content of phytochemicals except in broccoli, although some changes in the individual content of the target compounds were observed, suggesting that interconversion processes could be performed during the lifetime and/or cooking process of the product.

Degradation of limonene and trans-cinnamaldehyde in soil, and detection of their metabolites by UHPLC and GC-HRMS.

Two commercial biopesticides were studied to determine their persistence in two soil types, such as sandy clay loam and clay loam soils. For this purpose, an orange oil-based biopesticide was used, being limonene its main ingredient. The other biopesticide was based on cinnamon extract and trans-cinnamaldehyde as its main component. Degradation of these compounds was monitored, and transformation products or metabolites were detected. Limonene and its metabolites were analyzed by gas chromatography (GC) and trans-cinnamaldehyde by ultra-high-performance liquid chromatography (UHPLC). Both techniques were coupled to a high-resolution mass (HRMS) analyzer, such as quadrupole (Q)-Orbitrap. Limonene and trans-cinnamaldehyde were rapidly degraded as result of first-order kinetics. Possible metabolites such as thymol, cymene, isoterpinolene and cymenene for limonene, and hydroxycinnamic acid for trans-cinnamaldehyde were tentatively identified. Moreover, four other metabolites of trans-cinnamaldehyde, some of them not previously described, were also detected.

Degradation study of the trans-cinnamaldehyde and limonene biopesticides and their metabolites in cucumber by GC and UHPLC-HRMS: Laboratory and greenhouse studies.

Degradation of trans-cinnamaldehyde and limonene in cucumber was evaluated under laboratory and greenhouse conditions. Two commercial biopesticides, one based on cinnamon extract and other from orange oil, were utilized. Compound degradation was monitored using gas chromatography (GC) and ultra-high-performance liquid chromatography (UHPLC) coupled to a quadrupole-high-resolution mass analyzer (Q-Orbitrap). In both studies, trans-cinnamaldehyde followed a second-order degradation kinetics, whereas limonene followed a first-order kinetics. The half-life values (DT50 or t1/2) for trans-cinnamaldehyde ranged from 2.02 to 2.49 h, while for limonene this value ranged from 0.49 to 6.17 h. Non-targeted analysis (suspect and unknown modes) allowed for the detection of trans-cinnamaldehyde and limonene metabolites. Benzyl alcohol, cinnamyl alcohol, cinnamic acid, p-tolylacetic acid and 4-hydoxycinnamic acid were tentatively identified as trans-cinnamaldehyde metabolites. While three limonene metabolites, carvone, limonene-1,2-epoxide, and perillyl alcohol, were tentatively identified. Greenhouse studies have not revealed any metabolites of these compounds because the parent compounds degrade more quickly.

Tracing the dissipation of difenoconazole, its metabolites and co-formulants in tomato: A comprehensive analysis by chromatography coupled to high resolution mass spectrometry in laboratory and greenhouse trials.

The study evaluated Ceremonia 25 EC®, a plant protection product (PPP) containing difenoconazole, in tomato crops, to identify potential risks associated with PPPs, and in addition to this compound, known metabolites from difenoconazole degradation and co-formulants present in the PPP were monitored. An ultra high performance liquid chromatography coupled to quadrupole-Orbitrap mass analyser (UHPLC-Q-Orbitrap-MS) method was validated with a working range of 2 µg/kg (limit of quantification, LOQ) to 200 µg/kg. Difenoconazole degradation followed a biphasic double first-order in parallel (DFOP) kinetic model in laboratory and greenhouse trials, with high accuracy (R2 > 0.9965). CGA-205374, difenoconazole-alcohol, and hydroxy-difenoconazole metabolites were tentatively identified and semi-quantified in laboratory trials by UHPLC-Q-Orbitrap-MS from day 2 to day 30. No metabolites were found in greenhouse trials. Additionally, 13 volatile co-formulants were tentatively identified by gas chromatography (GC) coupled to Q-Orbitrap-MS, detectable up to the 7th day after PPP application. This study provides a comprehensive understanding of difenoconazole dissipation in tomatoes, identification of metabolites, and detection of co-formulants associated with the applied PPP.

Development of novel methods based on GC-HRMS and LC-HRMS for the determination of non-phthalate plasticizers in soil.

Non-phthalate plasticizers (NPPs) are a suitable alternative to phthalates, which are harmful compounds for human, animal health, and the environment. In this study, 28 commercial non-phthalate plasticizers (NPPs) from different families, including adipates, citrates, phosphates, sebacates, trimellitates, benzoates and cyclohexanoates, were determined. Two novel methods for determining these alternative compounds in soil were developed using gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS-Q-Orbitrap) and liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS-Q-Orbitrap). Solid-liquid extraction (SLE) with ethyl acetate or acetonitrile, along with water as extraction solvents, were employed. In most cases, the GC method exhibited recoveries ranging from 84.9 % to 110.8 % at 20, 40 and 200 µg/kg, while the LC method achieved recoveries between 73.1 % and 115.4 % at 10, 20, 40 and 200 µg/kg. Most of the relative standard deviation (RSD) values were below 20 % for both methods. The validated methods were then applied to analyse soil samples collected from four different areas in Almeria. The results indicated that the compounds detected most frequently at high concentrations were 1-hydroxycyclohexyl phenyl ketone (HCPK) using GC, in the range 29.1-67.4 µg/kg and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB) using LC, in the range 39.9-51.5 µg/kg. Additionally, suspect and unknown analysis were carried out, and other plasticizers as phthalates, were also detected, in addition to other substances present in the analysed samples. All the soils exhibited the presence of a few plasticizers, either phthalic and/or non-phthalic.