Analysing polypeptide antibiotics residues in animal muscle tissues: The crucial role of HRMS.

A confirmatory method for the determination of polypeptide antibiotics (bacitracin, colistin, and polymyxin B) in muscle samples has been developed. Extraction is performed with acidified methanol, and a clean-up step by solid-phase extraction with polymeric cartridges is applied. Separation by ultra-high performance liquid chromatography (UHPLC) is carried out using a solid core C18 column and gradient elution with water/acetonitrile containing 0.

Sources of persistent organic pollutants and their physiological effects on opportunistic urban gulls.

Urbanization is associated with drastic shifts in biodiversity. While some species thrive in urban areas, the impact of inhabiting these human-altered environments on organism physiology remains understudied. We investigated how exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) affects the physiology of yellow-legged gulls (Larus michahellis) inhabiting a densely populated, industrialized city.

Exposure to secondhand and thirdhand smoke in private vehicles: Measurements in air and dust samples.

Background: This study aimed to estimate airborne nicotine concentrations and nicotine, cotinine, and tobacco-specific nitrosamines (TSNAs) in settled dust from private cars in Spain and the UK.

Methods: We measured vapor-phase nicotine concentrations in a convenience sample of 45 private cars from Spain (N = 30) and the UK (N = 15) in 2017-2018. We recruited non-smoking drivers (n = 20), smoking drivers who do not smoke inside the car (n = 15), and smoking drivers who smoke inside (n = 10).

Measurement of airborne nicotine, as a marker of secondhand smoke exposure, in homes with residents who smoke in 9 European countries.

Objective: Smoke-free policies are effective in preventing secondhand smoke (SHS) exposure, but their adoption at home remains largely voluntary. This study aimed to quantify SHS exposure in homes with residents who smoke in Europe according to households' characteristics, tobacco consumption habits, and national contextual factors.

Methods: Cross-sectional study (March 2017-September 2018) based on measurements of air nicotine inside 162 homes with residents who smoke from nine European countries.

Secondhand smoke exposure assessment in outdoor hospitality venues across 11 European countries.

Objective: Due to partial or poorly enforced restrictions secondhand tobacco smoke (SHS) is still present in outdoor hospitality venues in many European countries. This study aimed to assess SHS concentrations in outdoor hospitality venues across Europe and identify contextual exposure determinants.

Methods: Cross-sectional study.

Secondhand smoke exposure in outdoor children's playgrounds in 11 European countries.

Introduction: Tobacco presence in outdoor children's playgrounds is concerning not only because it leads to secondhand smoke (SHS) exposure, but also cigarette butt pollution and tobacco normalization.

Objectives: This study aimed to assess SHS exposure in children's playgrounds, according to area-level socioeconomic status (SES), smoke-free regulations, national smoking prevalence, and SHS exposure prevalence in playgrounds (2017-2018).

Methods: We monitored vapor-phase nicotine concentration and tobacco-related variables in 20 different playgrounds in 11 European countries (n = 220 measurements) from March 2017 to April 2018.

Secondhand smoke exposure and other signs of tobacco consumption at outdoor entrances of primary schools in 11 European countries.

Introduction: Although smoking restrictions at child-related settings are progressively being adopted, school outdoor entrances are neglected in most smoke-free policies across Europe.

Objectives: To describe secondhand smoke (SHS) exposure and tobacco-related signs in outdoor entrances of primary schools in Europe according to area-level socioeconomic status (SES), smoke-free policy, national smoking prevalence, and geographical region.

Methods: In this cross-sectional study we monitored vapor-phase nicotine concentrations at 220 school outdoor entrances in 11 European countries (March 2017-October 2018).

Validity of self-reported indicators to assess secondhand smoke exposure in the home.

Introduction: Questionnaires are widely used to assess secondhand smoke (SHS) exposure. However, the validity of self-reported SHS exposure indicators has been rarely assessed. We aimed to assess correlations, sensitivity, specificity, and predictive values between self-reported SHS exposure indicators and airborne nicotine concentrations.

Second-hand smoke exposure in homes with children: assessment of airborne nicotine in the living room and children's bedroom.

Background: The introduction of 'smoke-free laws' has reduced the population's exposure to second-hand smoke (SHS), although SHS is still an issue in homes and other public places. Children are vulnerable to its health effects, and their greatest exposure occurs at home.

Objectives: To assess airborne nicotine concentration of the living room and children's bedroom of homes with children under 13 years of age, and to analyse factors associated with these levels.

Epicuticular Wax in Developing Olives (Olea europaea) Is Highly Dependent upon Cultivar and Fruit Ripeness.

The epicuticular wax (EW) layer is located on the surface of most plant organs. It provides the cuticle with most of its properties and is the primary barrier against biotic and abiotic stress. Despite the importance of Olea europaea cultivation, few studies have characterized the EW covering leaves and olives, which could be involved in resistance to both infection and environmental conditions.

Ripening and storage conditions of Chétoui and Arbequina olives: Part II. Effect on olive endogenous enzymes and virgin olive oil secoiridoid profile determined by high resolution mass spectrometry.

Several factors affect virgin olive oil (VOO) phenolic profile. The aim of this study was to monitor olive hydrolytic (β-glucosidase) and oxidative (peroxydase, POX, and polyphenoloxydase, PPO) enzymes during olive ripening and storage and to determine their capacity to shape VOO phenolic profile. To this end, olives from the cultivars Chétoui and Arbequina were stored at 4°C or 25°C for 4weeks and their enzymatic activities and oil phenolic profiles were compared to those of ripening olives.

Direct chemical profiling of olive (Olea europaea) fruit epicuticular waxes by direct electrospray-ultrahigh resolution mass spectrometry.

In the present paper, an electrospray ionization (ESI)-Orbitrap method is proposed for the direct chemical profiling of epicuticular wax (EW) from Olea europaea fruit. It constitutes a rapid and efficient tool suitable for a wide-ranging screening of a large number of samples. In a few minutes, the method provides a comprehensive characterization of total EW extracts, based on the molecular formula of their components.

Fragmentation studies for the structural characterization of marine dissolved organic matter.

High-resolution tandem mass spectrometry by collision-induced dissociation with a linear ion trap-Orbitrap has been performed on marine dissolved organic matter (DOM). Product ion spectra of selected precursor ions (m/z 359-375) have been acquired to obtain structural information, after method development. To evaluate the performance of the method, the Suwannee River fulvic acid (SRFA) reference standard was also analyzed.

Analysis of volatile thiols in alcoholic beverages by simultaneous derivatization/extraction and liquid chromatography-high resolution mass spectrometry.

A simultaneous derivatization/extraction method followed by liquid chromatography-electrospray-high resolution mass spectrometry for the determination of volatile thiols in hydroalcoholic matrixes was optimized and used to identify and quantify volatile thiols in wine and beer samples. The method was evaluated in terms of sensitivity, precision, accuracy and selectivity. The experimental LOQs of eleven thiols tested ranged between 0.

Determination of volatile thiols in roasted coffee by derivatization and liquid chromatography-high resolution mass spectrometric analysis.

A fast derivatization/extraction method followed by LC-ESI-HRMS was optimized for the determination of volatile thiols in roasted coffee powder, using ebselen as the derivatization agent. The analytical conditions were optimized on real coffee matrix, which was spiked with representative volatile thiols. The method sensitivity, precision, accuracy and selectivity were evaluated by using representative standard thiols.

High-field FT-ICR mass spectrometry and NMR spectroscopy to characterize DOM removal through a nanofiltration pilot plant.

Ultrahigh resolution Fourier transform ion cyclotron mass spectrometry and nuclear magnetic resonance spectroscopy were combined to evaluate the molecular changes of dissolved organic matter (DOM) through an ultrafiltration-nanofiltration (UF-NF) pilot plant, using two dissimilar NF membranes tested in parallel. The sampling was performed on seven key locations within the pilot plant: pretreated water, UF effluent, UF effluent after addition of reagents, permeate NF 1, permeate NF 2, brine NF 1 and brine NF 2, during two sampling campaigns. The study showed that there is no significant change in the nature of DOM at molecular level, when the water was treated with UF and/or with the addition of sodium metabisulfite and antiscaling agents.

Determination of lipophilic marine toxins in mussels. Quantification and confirmation criteria using high resolution mass spectrometry.

A multitoxin method has been developed for quantification and confirmation of lipophilic marine biotoxins in mussels by liquid chromatography coupled to high resolution mass spectrometry (HRMS), using an Orbitrap-Exactive HCD mass spectrometer. Okadaic acid (OA), yessotoxin, azaspiracid-1, gymnodimine, 13-desmethyl spirolide C, pectenotoxin-2 and Brevetoxin B were analyzed as representative compounds of each lipophilic toxin group. HRMS identification and confirmation criteria were established.

Determination of volatile thiols in virgin olive oil by derivatisation and LC-HRMS, and relation with sensory attributes.

Volatile thiols were determined by derivatisation followed by ESI-LC-HRMS in twenty-five virgin olive oils (VOOs) pertaining to different commercial classes. 4-Methoxy-2-methyl-2-butanethiol (4MMB) was quantified, and 3-methyl-2-butenethiol and methanethiol were identified for the first time in VOO by non-target analysis. In order to evaluate the influence of volatile thiols on VOO aroma, the sensory notes, defects and secondary attributes were determined in samples according to European regulation by an Official VOO Panel.

Determination of volatile thiols in lipid matrix by simultaneous derivatization/extraction and liquid chromatography-high resolution mass spectrometric analysis. Application to virgin olive oil.

A simple, reliable, selective and sensitive method for the determination of volatile thiols at trace levels in lipid matrices was developed. The method consisted of a single-step derivatization/extraction procedure followed by electrospray ionization-high performance liquid chromatography-high resolution mass spectrometry (ESI-HPLC-HRMS) analysis using ebselen as a derivatization agent. The analytical conditions were optimized in a lipid model system (triolein) and virgin olive oil (VOO), both spiked with seven representative volatile thiols.

Molecular characterization of dissolved organic matter through a desalination process by high resolution mass spectrometry.

The effect of different water treatments such as ultrafiltration (UF) and reverse osmosis (RO) on dissolved organic matter (DOM) is still unknown. Electrospray ionization Fourier transform orbitrap mass spectrometry has been used to provide valuable information of marine DOM evolution through a desalination process on a molecular scale. In the present manuscript, the characterization of four real composite water samples from a desalination pilot plant installed in the coast of Barcelona (Spain) has been carried out.

Insight into virgin olive oil secoiridoids characterization by high-resolution mass spectrometry and accurate mass measurements.

With the aim to enhance characterization of virgin olive oil (VOO), high resolution mass spectrometry (HRMS) and high resolution tandem mass spectrometry (HRMS/MS), in positive and negative electrospray ionization (ESI) modes, coupled to fused-core reverse phase chromatography, were applied to distinct VOO phenolic extracts after the optimization of chromatographic conditions, ESI and fragmentation parameters. HRMS, but also HRMS/MS resulted fundamental to progress in secoiridoids structural elucidation. The former revealed that the secoiridoid composition of VOO was far more complicated than previously reported, while the latter helped clarify product ion elemental composition allowing new fragmentations, in addition to those reported in the literature, to be put forward.

Targeted analysis with benchtop quadrupole-orbitrap hybrid mass spectrometer: application to determination of synthetic hormones in animal urine.

Sensitive and unequivocal determination of analytes/contaminants in complex matrices is a challenge in the field of food safety control. In this study, various acquisition modes (Full MS/AIF, Full MS+tMS/MS, Full MS/dd MS/MS and tSIM/ddMS/MS) and parameters of a quadrupole-orbitrap hybrid mass spectrometer (Q Exactive) were studied in detail. One of the main conclusions has been that, reducing the scan range for Full MS (using the quadrupole) and targeted modes give higher signal-to-noise (S/N) ratios and thereby better detection limits for analytes in matrix.

Liquid chromatography coupled to tandem mass spectrometry and high resolution mass spectrometry as analytical tools to characterize multi-class cytostatic compounds.

Cytostatic compounds used in the treatment of cancer have emerged as a new generation of water contaminants due to the continuous amounts administered to patients and to the fact that a variable proportion is excreted unchanged. In this study, we have evaluated the performance of liquid-chromatography-tandem mass spectrometry (LC-MS/MS) and high resolution mass spectrometry using an Orbitrap analyzer (LC-HRMS) for the multiresidue determination of multi-class cytostatic compounds. In a first step, ionization conditions were tested in positive electrospray mode and optimum fragmentation patterns were determined.

Ultrahigh resolution mass spectrometry and accurate mass measurements for high-throughput food lipids profiling.

In the present study, accurate mass measurements by ultrahigh resolution mass spectrometry with Orbitrap-Exactive working at resolving power R: 100,000 (m/z 200, full width at half maximum) with an accuracy better than 2 ppm in all the mass range (m/z 200 to 2000) were used to show a detailed molecular composition of diverse edible oils and fats. Flow injection was used to introduce samples into the mass spectrometer, obtaining a complete analysis of each sample in less than 10 min, including blanks. Meticulous choice of organic solvents and optimization of the ion source and Orbitrap mass analyzer parameters were carried out, in order to achieve reproducible mass spectra giving reliable elemental compositions of the lipid samples and to prevent carry over.

Occurrence of cyclophosphamide and epirubicin in wastewaters by direct injection analysis-liquid chromatography-high-resolution mass spectrometry.

Background, Aim, And Scope: According to the high incidence of cancer worldwide, the amount of cytostatic drugs administered to patients has increased. These compounds are excreted to wastewaters, and therefore become potential water contaminants. At this stage, very little is known on the presence and elimination of cytostatic compounds in wastewater treatment plants (WWTP).