Environmental analytical chemists face the challenge of investigating thousands of potential 13 organic pollutants that may be present in the aquatic environment. High resolution mass 14 spectrometry (HRMS) hyphenated to chromatography offers the possibility of detecting a 15 large number of contaminants without pre-selection of analytes due to its accurate-mass full-16 spectrum acquisition at good sensitivity. Interestingly, large screening can be made even 17 without reference standards, as the valuable information provided by HRMS allows the 18 tentative identification of the compound detected. In this work, hybrid quadrupole time-of-19 flight (QTOF) MS was combined with both liquid and gas chromatography (using a single 20 instrument) for screening of around 2,000 compounds in waters. This was feasible thanks to 21 the use of atmospheric pressure chemical ionization source in GC. The screening was 22 qualitatively validated for around 300 compounds at three levels (0.02, 0.1, 0.5 µg/L), and 23 screening detection limits were established. Surface, ground water and effluent wastewater 24 samples were analyzed, detecting and identifying a notable number of pesticides and 25 transformation products, pharmaceuticals, personal care products, and illicit drugs, among 26 others. This is one of the most universal approaches in terms of comprehensive measurement 27 for broad screening of organic contaminants within a large range of polarity and volatility in 28 waters. 29 30 KEYWORDS: liquid chromatography, gas chromatography, quadrupole time of flight 31 mass spectrometry, universal screening, water samples, organic micropollutants 32 33 3 34 INTRODUCTION 35Over the last decades, environmental pollution has become a matter of increasing concern 36 due to the high number of both regulated and unregulated organic pollutants that can be 37 present in environmental waters. The majority of these compounds, such as pesticides, 38 pharmaceuticals, drugs of abuse, surfactants, biocides, personal care products, sweeteners, 39 etc. are originated by human use. They can enter in the surface water (and even groundwater) 40 mainly via treated and untreated wastewater [1][2]. Despite the evident advances in analytical 41 chemistry, the comprehensive determination of organic contaminants in waters is still a 42 challenge at present. The main difficulty arises from the elevated number of compounds (in 43 addition to their metabolites and/or transformation products) that may be present in the 44 samples. This fact, together with the very different physico-chemical properties of analytes, 45makes the application of a single analytical methodology, appropriate for all potential 46 contaminants, unfeasible. 47 Most analytical methods developed until now have used chromatographic techniques coupled 48to mass spectrometry (MS) analyzers, as single quadrupole or ion trap, and in the last decade, 49 triple quadrupole. In these target methods, the list of analytes rarely exceeds 200-300 50 compounds, and relevant contaminants other than the ...

The novel atmospheric pressure chemical ionization (APCI) source has been used in combination with gas chromatography (GC) coupled to hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) for determination of volatile components of olive oil, enhancing its potential for classification of olive oil samples according to their quality using a metabolomics-based approach. The full-spectrum acquisition has allowed the detection of volatile organic compounds (VOCs) in olive oil samples, including Extra Virgin, Virgin and Lampante qualities. A dynamic headspace extraction with cartridge solvent elution was applied. The metabolomics strategy consisted of three different steps: a full mass spectral alignment of GC-MS data using MzMine 2.0, a multivariate analysis using Ez-Info and the creation of the statistical model with combinations of responses for molecular fragments. The model was finally validated using blind samples, obtaining an accuracy in oil classification of 70%, taking the official established method, "PANEL TEST", as reference.

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The solid-waste treatment plant of RECIPLASA is located in the municipality of Onda (Castellón province), which is an important agricultural area of Spain, with predominance of citrus crops. In this plant, all urban solid wastes from the town of Castellón (around 200.000 inhabitants) and other smaller towns as Almassora, Benicàssim, Betxí, Borriana, L'Alcora, Onda and Vila-Real are treated. In order to evaluate the potential impact of this plant on the surrounding water, both surface and groundwater, a comprehensive monitoring of organic pollutants has been carried out along 2011, 2012 and 2013. To this aim, an advanced analytical strategy was applied for wide-scope screening, consisting on the complementary use of liquid chromatography (LC) and gas chromatography (GC) coupled to mass spectrometry (MS) with quadrupole (Q)-time of flight analyser (TOF). A generic solid-phase extraction with Oasis HLB cartridges was applied prior to the chromatographic analysis. The screening included more than 1,500 organic pollutants as target compounds, such as pesticides, pharmaceuticals, veterinary drugs, drugs of abuse, UV-filters, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), among others. Pesticides, mainly herbicides, were the compounds more frequently detected. Other compounds as antioxidants, cosmetics, drugs of abuse, PAHs, pharmaceuticals and UV filters, were also identified in the screening though at much lower frequency.Once the screening was made, quantitative analysis focused on the compounds more frequently detected was subsequently applied using LC coupled to tandem MS with triple quadrupole analyzer. In this way, up to 24 pesticides and transformation products (TPs), 7 pharmaceuticals, one drug of abuse and its metabolite could be quantified at sub-ppb concentrations. Along the three years of study, ten compounds were found at 3 concentrations higher than 0.1 g/L. Most of them were pesticides and TPs, a fact that illustrates that the main source of pollution seems to be the agricultural activities in this area.

8 In this work, the capability of gas chromatography coupled to time-of-flight mass 9 spectrometry (GC-TOF MS) for quantitative analysis of pesticide residues has been 10 evaluated. A multiclass method for rapid screening of pesticides (insecticides, 11 acaricides, herbicides and fungicides) in fruit and vegetable matrices has been 12 developed and validated, including detection, identification and quantification of the 13 analytes. To this aim, several food matrices were selected: high water content (apples, 14 tomatoes and carrots), high acid content (oranges) and high oil content (olives) samples. 15The well known QuEChERS procedure was applied for extraction of pesticides, and