Portable dehumidifiers condensed water: A novel matrix for the screening of semi-volatile compounds in indoor air

The comprehensive identification of organic species existing in indoor environments is a key issue to understand their impact in human health. This study proposes the analysis of condensed water samples, collected with portable dehumidifiers, to characterize semi-volatile compounds in the gas phase of confined areas. Water samples are concentrated by solid-phase extraction (SPE). The obtained extracts are analysed by gas chromatography (GC) time-of-flight mass spectrometry (TOF-MS), following a non-target screening data mining approach. In first term, spectra of deconvoluted compounds are compared with those in NIST low resolution library; thereafter, tentative identifications are verified using an in-house database of accurate electron ionization (EI) MS spectra. Chromatographic (retention index) and spectral data are combined for unambiguous species identification. The potential of condensed water samples to reflect changes in the composition of indoor atmospheres, the match between data obtained using different dehumidifiers, and the relative concentration efficiency of condensed water compared to that attained by active sampling of moderate air volumes are discussed. A total of 141 semi-volatile compounds were identified (98 confirmed against authentic standards) in a set of 21 samples obtained from different homes and working places. This list contains more than 40 fragrances (including several potential allergens), solvents and intermediates in the production of polymeric materials, plasticizers and flame retardantsThis study was supported by Xunta de Galicia and Spanish Government through grants GRC-ED431C 2017/36 and PGC2018-094613-B-I00, both co-funded by the EUS

Identification and determination of emerging pollutants in sewage sludge driven by UPLC-QTOF-MS data mining

Sludge from sewage treatment plants (STPs) is recognized as a sink of moderate to high lipophilic compounds resistant to biodegradation. Herein, we investigate the presence of emerging pollutants in sewage sludge combining the information provided by mass spectrometry detection, following ultra-performance liquid chromatography (UPLC), with the use of an accurate spectral database of pesticides and pharmaceuticals. In a first step, the performance of matrix solid-phase dispersion, as sample preparation technique, and two non-target data acquisition strategies (data dependent, DDA, and data independent analysis modes, DIA), used in combination with a UPLC quadrupole time-of-flight system, are assessed using a selection of deuterated compounds added either to freeze-dried sludge samples, or to sludge extracts. Possibilities and limitations of both modes are discussed. Following the DDA approach, a group of 68 micropollutants was identified in sludge from different STPs. Some of them are reported in this compartment for the first time. Finally, semi-quantitative concentration data are reported for a group of 37 pollutants in samples obtained from 16 STPs. Out of them, 10 pharmaceuticals, showing detection frequencies and median sludge residues above 50% and 100 ng g−1, respectively; are highlighted as pollutants to be monitored in sludge in order to understand their behaviour during the wastewater treatmentThis study was supported by Xunta de Galicia and Spanish Government through grants GRC-ED431C 2017/36, PGC2018-094613-B-I00, both co-funded by the EU FEDER programS

Determination of pesticide residues in wine by solid-phase extraction on-line combined with liquid chromatography tandem mass spectrometry

Liquid chromatography tandem mass spectrometry (LC–MS/MS) has been combined with different sample preparation strategies to determine potential pesticide residues existing in wine. Herein, we propose the on-line coupling between solid-phase extraction (SPE), based on a reversed-phase polystyrene-divinyl benzene (PS-DVB) sorbent, and LC–MS/MS for the automated monitoring of a selection of 48 pesticides (37 fungicides and 11 insecticides) in this beverage. Parameters affecting the sensitivity, selectivity, accuracy and robustness of the method are evaluated as function of sample volume, clean-up conditions, and number of extraction-desorption cycles performed with the same SPE cartridgeL.P.M thanks a FPU grant to the Spanish Ministry of Science. This study was supported by Spanish Government and Xunta de Galicia through grants PGC2018-094613-B-I00 and ED431C 2021/06, both co- funded by the EU FEDER program. We acknowledge Agilent for providing access to the LC-ESI-MS/MS instrumentation employed in this studyS

Selective determination of sartan drugs in environmental water samples by mixed-mode solid-phase extraction and liquid chromatography tandem mass spectrometry

This is the accepted manuscript of the following article: Castro, G., Rodríguez, I., Ramil, M., & Cela, R. (2019). Selective determination of sartan drugs in environmental water samples by mixed-mode solid-phase extraction and liquid chromatography tandem mass spectrometry. Chemosphere, 224, 562-571. doi: 10.1016/j.chemosphere.2019.02.137Herein, a method for the simultaneous determination of the currently prescribed sartan drugs (eprosartan, EPR; olmesartan, OLM; losartan, LOS; candesartan, CAN; telmisartan, TEL; irbesartan, IRB; and valsartan, VAL), and the biodegradation product valsartan acid (VALA), in water samples (raw and treated wastewater, river and tap water) was developed. Solid-phase extraction (SPE) and ultra-performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) were employed as concentration and determination techniques, respectively. Different sorbents and elution solvents were tested for sample preparation. Under optimized conditions, samples at neutral pH (6–8 units) were concentrated using mixed-mode (reversed-phase and anionic exchange) cartridges. Thereafter, the sorbent was washed with 5 mL of a methanol: water (1:1) solution, dried under a nitrogen stream and compounds were eluted with 2 mL of methanol: NH3 (98:2). The accuracy of the method (accounting for SPE efficiency and matrix effects during electrospray ionization) was investigated using solvent-based calibration standards. Global recoveries, obtained for different water matrices (tap, river, treated and raw wastewater), ranged from 82% to 134%, with standard deviations between 2 and 18%. LOQs varied from 2 to 50 ng L−1. Analysis of un-spiked samples confirmed: (1) the incomplete removal of sartans at sewage treatment plants (STPs), (2) the formation of VALA during municipal water treatment, and (3) the presence of VALA in the processed tap water samples. Additional findings of the current study are the detection of hydroxylated derivatives of the sartan drugs IRB and LOS in wastewater, and the E-Z isomerization of EPR in environmental water samplesThis study was supported by Xunta de Galicia (grant GRC-ED431C 2017/36), and the Spanish Government (grant CTQ2015-68660-P)S

Supercritical fluid chromatography-mass spectrometric determination of chiral fungicides in viticulture-related samples

Supercritical fluid chromatography (SFC), combined with mass spectrometry (MS), was employed for the determination of five chiral fungicides, from two different chemical families (acylalanine and triazol) in wine and vineyard soils. The effect of different SFC parameters (stationary phase, chiral selector, mobile phase modifier and additive) in the resolution between enantiomers and in the efficiency of compounds ionization at the electrospray source (ESI) was thorougly described. Under final working conditions, chiral separations of selected fungicides were achieved using two different SFC-MS methods, with an analysis time of 10 min and resolution factors from 1.05 to 2.45 between enantiomers. In combination with solid-phase extraction and pressurized liquid extraction, they permitted the enantiomeric determination of target compounds in wine and vineyard soils with limits of quantification in the low ppb range (between 0.5 and 2.5 ng mL−1, and from 1.3 to 6.5 ng g−1, for wine and soil, respectively), and overall recoveries above 80%, calculated using solvent-based standards. For azolic fungicides (tebuconazole, myclobutanil and penconazole) soil dissipation and transfer from vines to wines were non-enantioselective processes. Data obtained for acylalanine compounds confirmed the application of metalaxyl (MET) to vines as racemate and as the R-enantiomer. The enantiomeric fractions (MET-S/(MET-S+MET-R)) of this fungicide in vineyard soils varied from 0.01 to 0.96; moreover, laboratory degradation experiments showed that the relative dissipation rates of MET enantiomers varied depending on the type of soilL.P.M acknowledges a FPU grant to the Spanish Ministry of Science. This study was supported by Xunta de Galicia and Spanish Government through grants GRC-ED431C 2017/36, PGC2018-094613-B-I00, both co-funded by the EU FEDER programS

Assessment of the occurrence and interaction between pesticides and plastic litter from vineyard plots

In this research, aged plastic fragments collected from vineyards were characterized in terms of composition, residues of pesticides, and their potential to exchange these compounds with the aquatic media. To this end, we employed the qualitative and quantitative information provided by complementary analytical techniques, including chromatography, organic and inorganic mass spectrometry, infrared spectroscopy and electronic microscopy. Debris of weathered plastics were identified as polypropylene and polyethylene, containing different types of additives, from organic UV stabilizers to inorganic fillers, such as calcium salts. Regardless of polymer type, plastic litter collected from vineyards contained residues of pesticides, and particularly of fungicides, with total concentrations in the range of values from 114 ng g 1 to 76.4 μg g 1. Data obtained under different extraction conditions suggested that a fraction of these compounds was absorbed in aged polymers, penetrating inside the material. The parallel analysis of plastic litter and vineyard soils reflected higher pesticide residues in the former matrix. Furthermore, several fungicides, considered as labile in vineyard soils (i.e. zoxamide and folpet), were those showing the highest levels in plastic litter. Simulated sorption-desorption studies, with plastic debris in contact with surface water, demonstrated the higher affinity of aged materials by moderately polar pesticides than their new counterparts. For the first time, the manuscript highlights the presence of plastic litter in vineyards soils, reflecting the accumulation of several fungicides in this matrix, in some cases, with a different stability pattern to that observed in the soil from same vineyardsEconomic support from projects TED2021-129962B-C42, funded by the Spanish Ministry of Science and Innovation, through the UE Next Generation program; and ED431C2021/06, from Xunta de Galicia, co- financed the EU FEDER program, is acknowledgedS

Approaches to liquid chromatography tandem mass spectrometry assessment of glyphosate residues in wine

The performance of two different analytical methodologies to investigate the presence of glyphosate (GLY) and aminomethylphosphonic acid (AMPA) residues in wine samples was evaluated. Transformation of compounds in their fluorene-9-methyloxycarbonyl derivatives permitted their separation under reversed-phase liquid chromatography with tandem mass spectrometry (LC–MS/MS) determination. Although the wine matrix severely impaired the efficiency of GLY derivatization, this drawback was solved using a molecularly imprinted sorbent for the previous, selective extraction of GLY and AMPA from wine. Alternatively, the use of a strong anionic exchange, polyvinyl alcohol-based LC column, turned to be the most effective alternative for direct determination of both compounds in diluted wine samples. The chromatographic behavior of this column and the magnitude of matrix effects observed during analysis of diluted wine samples were significantly affected by the composition of the mobile phase. Under final working conditions, this column permitted the separation of AMPA and the fungicide fosetyl (which shows common transitions in tandem MS/MS methods), it improved significantly the sample throughput versus extraction-derivatization-purification method, and it allowed the use of solvent-based calibration standards. Both analytical procedures provided similar limits of quantification (LOQs) for GLY (0.5–1.0 ng mL−1), while the multistep method was 8 times more sensitive to AMPA than the direct procedure. GLY residues stayed above method LOQs in 70% of the processed wines; however, concentrations measured in 95% of positive samples remained 100 times below the maximum residue limit (MRL) set for GLY in vinification grapesOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was supported by Spanish Government and Xunta de Galicia through grants PGC2018-094613-B-I00 and ED431C 2021/06, respectively. Both projects are co-funded by the EU FEDER programS

Assessment of direct analysis in real time accurate mass spectrometry for the determination of triclosan in complex matrices

In this work, the applicability of direct analysis in real time coupled to accurate mass spectrometry (DART-MS) to the quantitative determination of triclosan (TCS) in samples with increasing complexity, from personal care products to extracts from sewage, is investigated. In the first term, DART-MS spectra of TCS as free phenol and as derivatized species are characterized; thereafter, the effects of several instrumental variables in the detectability of TCS (i.e., temperature, solvent, and compound holder) are discussed. Under final selected conditions, TCS was determined from its [M-H]− ions, without need of derivatization, attaining an instrumental limit of quantification of 5 ng mL−1, with a linear response range up to 1000 ng mL−1. Complex matrices, such as solid-phase extracts obtained from environmental water samples, moderately inhibited the ionization efficiency of TCS, with signal attenuation percentages in the range of 6 to 57%, depending on the sample type and on the concentration factor provided by the SPE procedure. The accuracy of results obtained by DART-MS was evaluated using liquid chromatography (LC) with MS detection; in both cases, a time-of-flight (TOF) MS instrument was employed for the selective determination of the [M−H]− ions of TCS (m/z values 286.9439 and 288.9410) using a mass window of 20 ppm. DART-MS did not only provide enough sensitivity to detect the presence of TCS in environmental samples (raw and treated wastewater as well as freeze-dried sludge), but also measured concentrations matched those determined by LC-ESI-TOF-MS, with only slightly higher standard deviations. During analysis of personal care products, containing much higher concentrations of TCS in a less complex matrix, both techniques were equivalent in terms of accuracy and precisionThis study was supported by the Spanish Government and Xunta de Galicia through grants PGC2018-094613-B-I00 and ED431C 2021/06, co-funded by the EU. M. Cobo-Golpe thanks the Spanish Ministry of Science, Innovation and Universities for a FPI fellowshipS

Fabric phase sorptive extraction followed by ultra-performance liquid chromatography-tandem mass spectrometry for the determination of fungicides and insecticides in wine

This is the Author’s Accepted Manuscript of the following article: Pérez-Mayán, L., Rodríguez, I., Ramil, M., Kabir, A., Furton, K., & Cela, R. (2019). Fabric phase sorptive extraction followed by ultra-performance liquid chromatography-tandem mass spectrometry for the determination of fungicides and insecticides in wine. Journal Of Chromatography A, 1584, 13-23. doi: 10.1016/j.chroma.2018.11.025In this work, fabric phase sorptive extraction (FPSE) is investigated for the extraction and preconcentration of ultra-trace level residues of fungicides (19 compounds) and insecticides (3 species) in wine samples. Subsequently, the preconcentrated analytes are selectively determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Parameters affecting the efficiency and repeatability of the extraction are evaluated in depth; moreover, the proposed method is characterized in terms of linear response range, trueness, precision and limits of quantification (LOQs). The set-up of the extraction process and the type of coating were the variables exerting the most prominent effects in the repeatability and the yield of the extraction, respectively. Under optimized conditions, samples (10 mL of wine diluted with the same volume of ultrapure water) were extracted with a small amount of cellulose fabric (3 discs with 4 mm of diameter: total surface 0.38 cm2) coated with a sol-gel polyethylene glycol sorbent (sorbent amount 3.3 mg), immersed in the diluted sample, without being in direct contact with the PTFE covered magnetic stir bar. Following the overnight extraction step, analytes were quantitatively recovered using only 0.3 mL of an ACN-MeOH (80:20) mixture. Under equilibrium sampling conditions, the linear response range of the method varied from 0.2 to 200 ng mL−1, with limits of quantification (LOQs) between 0.03 and 0.3 ng mL−1. Relative recoveries ranged from 77 ± 6% to 118 ± 4%, and from 87 ± 4% to 121 ± 6% for red and white wines, respectively. Application of the optimized method to commercial wines demonstrated the existence of up to 9 out of 22 investigated compounds in the same wine sample. The compound identified at the highest concentration was iprovalicarb (IPR), with a value of 130 ± 9 ng mL−1 in a commercial white wineThis study has been supported by the Spanish Government, Xunta de Galicia and E.U. FEDER funds (projects CTQ2015-68660-P and GRC-ED431C). L.P-M acknowledges a FPU contract to the Spanish Ministry of EducationS

Comprehensive characterization of volatile and semi-volatile compounds in e-liquids for electronic cigarette using gas chromatography accurate mass spectrometry

The consumption of electronic cigarettes is a habit with an increasing prevalence, particularly among youths. Knowing the composition of e-liquids used in these devices represents the first step to understand the potential impact of e-smoking in the health of consumers. Herein, a non-target screening methodology was applied to the identification of volatile and semi-volatile compounds in a set of e-liquids from different suppliers, with different flavors, and containing different kinds of additives, such as nicotine or cannabidiol. To this end, samples were characterized by gas chromatography accurate mass spectrometry, using a time-of-flight mass analyzer. Combination of deconvoluted electronic ionization mass spectra with linear retention index values, obtained for two columns with different selectivity, permitted the identification of more than 250 chemicals with different confidence levels. Among them, respiratory pro-inflammatory compounds, acetals of propylene glycol and glycerin with aldehydes, nicotine-related and non-related alkaloids, and psychoactive cannabinoids were confirmed as concerning compounds in e-liquid samples. Concentration ratios between propylene glycol acetals and parent aldehydes varied in the range from 2% (ethyl vanillin) to more than 80% (case of benzaldehyde). The ratios between the concentrations of delta-9-tetrahydrocannabinol and cannabidiol in e-liquids stayed in the range from 0.02% to 0.3%M.C.G. thanks a FPI pre-doctoral grant to the Spanish Ministry of Science & Innovation. This study was supported by Spanish Government and Xunta de Galicia through grants PGC2018–094613-B-I00 and ED431C 2021/06, respectively. Both projects are co-funded by the EU FEDER programS