Determination of PBDEs in human breast adipose tissues by gas chromatography coupled with triple quadrupole mass spectrometry

The role of adipose tissue analysis on Environmental Pollutants Biomonitoring in women: The European scenario

Humans are exposed every day to assorted environmental pollutants namely, polychlorinated biphenyls (PCB), organochlorine pesticides (OCP), brominated flame-retardants (BFR), polycyclic aromatic hydrocarbons (PAH), synthetic musks, heavy metals (e.g. cadmium) and plastic additives (e.g. bisphenol A, BPA). Besides environmental persistence, biomagnification and bioaccumulative properties, these pollutants are classified as endocrine disruptors (EDs), metabolic disruptors, neurologic disruptors. These compounds affect the normal function of several mechanisms in the human body being linked to human health issues as cancer development (e.g. breast, uterine and endometrial), miscarriage, birth defects, premature delivery and infertility. In order to prevent future health issue of women and possible progeny, the assessment of EDs accumulated is essential, particularly in adipose tissue. These samples have been referred as the ideal matrix to establish over time accumulation and long-term exposure of persistent and non-persistent lipophilic EDs. However, the invasive sample collection procedure and methodology processing discourages the usage of this matrix for biomonitoring studies. In this review, a Web of Science search without any publishing year restriction on the analysis in adipose tissue of PCB, OCP, BPA, cadmium, BFR and synthetic musks was performed. A total of 313 studies were found, 158 were European studies from which the studies with data on women EDs accumulation were selected for detailed analysis (n = 90). The results were structured and presented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The present paper is an overview on the existent EDs analytical methods and levels accumulated in women adipose tissue, with the correspondent health implications across Europe. The limits of detection and quantification were compared and a discussion with results obtained about the presence of ED was performed.

Polybrominated diphenyl ethers in foods from the Region of Valencia: Dietary exposure and risk assessment

Dietary exposure to polybrominated diphenyl ethers (PBDEs) of the population in the Region of Valencia, Spain, was assessed. A group of 320 composite samples of different fatty foods was collected and analyzed, including the following: vegetable oils, and foods of animal origin such as (a) fish and seafood, (b) eggs, (c) milk and dairy products, and (d) meat and meat products. Two scenarios were assumed for left-censored results: lower-bound (LB) and upper-bound (UB). Vegetable oils, and fish and seafood presented the highest content of PBDEs [mean values of 503 and 464 pg g^-1 wet weight (ww) for total PBDEs, respectively, in the UB]. The dominating congeners were BDE47 in the food categories of fish and seafood, meat and meat products, and vegetable oils, and BDE99 in the categories of eggs, and milk and dairy products. The dietary exposure to PBDEs through consumption of the studied foods by the population in the Region of Valencia was estimated for adults (>15 years of age) and young people (6-15 years of age). Average intake levels (UB scenario) were 1.443 and 3.456 ng kg bw^-1 day^-1 for adults and young people, respectively. In a risk-assessment context, the margin of exposure (MOE) for congener BDE47, -99, -153, and -209 (ranged: 30-3E6) indicate that the current dietary exposure to these substances does not pose a risk to human health.

Trends in the application of high-resolution mass spectrometry for human biomonitoring: An analytical primer to studying the environmental chemical space of the human exposome

Global profiling of xenobiotics in human matrices in an untargeted mode is gaining attention for studying the environmental chemical space of the human exposome. Defined as the study of a comprehensive inclusion of environmental influences and associated biological responses, human exposome science is currently evolving out of the metabolomics science. In analogy to the latter, the development and applications of high resolution mass spectrometry (HRMS) has shown potential and promise to greatly expand our ability to capture the broad spectrum of environmental chemicals in exposome studies. HRMS can perform both untargeted and targeted analysis because of its capability of full- and/or tandem-mass spectrum acquisition at high mass accuracy with good sensitivity. The collected data from target, suspect and non-target screening can be used not only for the identification of environmental chemical contaminants in human matrices prospectively but also retrospectively. This review covers recent trends and advances in this field. We focus on advances and applications of HRMS in human biomonitoring studies, and data acquisition and mining. The acquired insights provide stepping stones to improve understanding of the human exposome by applying HRMS, and the challenges and prospects for future research.

Review of contamination of sewage sludge and amended soils by polybrominated diphenyl ethers based on meta-analysis

Polybrominated diphenyl ethers (PBDEs) are still present in sewage sludge and sludge-amended soil, even though commercial PBDEs were prohibited or voluntarily phased out several years ago. In this study, levels and compositional profiles of seven major PBDE congeners in sludge are assessed in relation to their usage patterns in commercial products, and years of being banned and phased out in North America, Europe, and Asia. Annual accumulations and future long-term changes of PBDE in sludge-amended soil are estimated. BDE-209 has the highest concentration, followed by BDE-99 and BDE-47. The highest concentrations, up to 23,500 ng g^-1, of PBDEs in sludge were found in North America until 2004-2007, whereas since then sludge PBDE concentrations, up to 6600 ng g^-1 have been higher in Asia than on the other two continents. The amount of sludge applied and the soil organic matter content play important roles in determining PBDE concentrations in sludge-amended soil. The estimated concentrations of BDE-47, -99, and -209 in soils receiving sludge applications during the past 15 years are 40-300 times higher than in soils after the initial sludge application. The accumulated concentrations of BDE-47 and BDE-99 are expected to decrease by 99% between 2016 and 2100, whereas the decrease in the BDE-209 concentration is predicted to be approximately 87%.

Applicability of Gas Chromatography (GC) Coupled to Triple-Quadrupole (QqQ) Tandem Mass Spectrometry (MS/MS) for Polybrominated Diphenyl Ether (PBDE) and Emerging Brominated Flame Retardant (BFR) Determinations in Functional Foods Enriched in Omega-3

This paper reports on the optimization, characterization, and applicability of gas chromatography coupled to triple-quadrupole tandem mass spectrometry (GC-QqQ(MS/MS)) for the determination of 14 polybrominated diphenylethers (PBDEs) and 2 emerging brominated flame retardants, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE), in functional food samples. The method showed satisfactory precision and linearity with instrumental limits of detection (iLODs) ranging from 0.12 to 7.1 pg, for tri- to octa-BDEs and BTBPE, and equal to 51 and 20 pg for BDE-209 and DBDPE, respectively. The highest ΣBFR concentrations were found in fish oil supplements (924 pg/g fresh weight, fw), followed by biscuits (90 pg/g fw), vegetable oil supplements (46 pg/g fw), chicken eggs (45 pg/g fw), cow's milk (7.7 pg/g fw), and soy products (1.6 pg/g fw). BDE-47, BDE-99, and DBDPE were the most abundant compounds. Foodstuffs enriched with omega-3 presented concentrations similar to or even lower than those of conventional foods commercialized in Spain since 2000.

Atmospheric pressure gas chromatography quadrupole-time-of-flight mass spectrometry for simultaneous determination of fifteen organochlorine pesticides in soil and water

In this study, the application of atmospheric pressure gas chromatography quadrupole-time-of-flight mass spectrometry (APGC-QTOF-MS) has been investigated for simultaneous determination of fifteen organochlorine pesticides in soil and water. Soft ionization of atmospheric pressure gas chromatography was evaluated by comparing with traditional more energetic electron impact ionization (EI). APGC-QTOF-MS showed a sensitivity enhancement by approximately 7-305 times. The QuEChERs (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was used to pretreat the soil samples and solid phase extraction (SPE) cleanup was used for water samples. Precision, accuracy and stability experiments were undertaken to evaluate the feasibility of the method. The results showed that the mean recoveries for all the pesticides from the soil samples were 70.3-118.9% with 0.4-18.3% intra-day relative standard deviations (RSD) and 1.0-15.6% inter-day RSD at 10, 50 and 500 μg/L levels, while the mean recoveries of water samples were 70.0-118.0% with 1.1-17.8% intra-day RSD and 0.5-12.2% inter-day RSD at 0.1, 0.5 and 1.0 μg/L levels. Excellent linearity (0.9931 ≦ r(2)≤ 0.9999) was obtained for each pesticides in the soil and water matrix calibration curves within the range of 0.01-1.0mg/L. The limits of detection (LOD) for each of the 15 pesticides was less than 3.00 μg/L, while the limit of quantification (LOQ) was less than 9.99 μg/L in soil and water. Furthermore, the developed method was successfully applied to monitor the targeted pesticides in real soil and water samples.

Optimization and Simultaneous Determination of Alkyl Phenol Ethoxylates and Brominated Flame Retardants in Water after SPE and Heptafluorobutyric Anhydride Derivatization followed by GC/MS

A gas chromatography–mass spectrometry (GC–MS) method was investigated for the simultaneous analysis of two types of endocrine disrupting compounds (EDCs), i.e., alkylphenol ethoxylates and brominated flame retardants (BFRs), by extraction and derivatization followed by GC–MS. Different solid phase extraction (SPE) cartridges (Cleanert PestiCarb, C₁₈, Cleanert-SAX and Florosil), solvents (toluene, tetrahydrofuran, acetone, acetonitrile and ethyl acetate) and bases (NaHCO₃, triethylamine and pyridine) were tested and the best chromatographic analysis was achieved by extraction with Strata-X (33 μm, Reverse Phase) cartridge and derivatization with heptafluorobutyric anhydride at 55 °C under Na₂CO₃ base in hexane. It was observed that APE together with lower substituted PBBs (PBB1, PBB10, PBB18 and PBB49), HBCD and TBBPA can be determined simultaneously under the same GC conditions. This simple and reliable analytical method was applied to determining trace amounts of these compounds from wastewater treatment plant samples. The recoveries of the target compounds from simulated water were above 60 %. The limit of detection ranged from 0.01 to 0.15 μg L⁻¹ and the limit of quantification ranged from 0.05 to 0.66 μg L⁻¹. There were no appreciable differences between filtered and unfiltered wastewater samples from Leeuwkil treatment plant although concentration of target analytes in filtered influent was slightly lower than the concentration of target analytes in unfiltered influent water. The concentrations of the target compounds from the wastewater treatment were determined from LOQ upwards.

Application of mass spectrometry in the analysis of polybrominated diphenyl ethers

This review summarized the applications of mass spectrometric techniques for the analysis of the important flame retardants polybrominated diphenyl ethers (PBDEs) to understand the environmental sources, fate and toxicity of PBDEs that were briefly discussed to give a general idea for the need of analytical methodologies. Specific performance of various mass spectrometers hyphenated with, for example, gas chromatograph, liquid chromatograph, and inductively coupled plasma (GC/MS, LC/MS, and ICP/MS, respectively) for the analysis of PBDEs was compared with an objective to present the information on the evolution of MS techniques for determining PBDEs in environmental and human samples. GC/electron capture negative ionization quadrupole MS (GC/NCI qMS), GC/high resolution MS (GC/HRMS) and GC ion trap MS (GC/ITMS) are most commonly used MS techniques for the determination of PBDEs. New analytical technologies such as fast tandem GC/MS and LC/MS become available to improve analyses of higher PBDEs. The development and application of the tandem MS techniques have helped to understand environmental fate and transformations of PBDEs of which abiotic and biotic degradation of decaBDE is thought to be one major source of Br(1-9)BDEs present in the environment in addition to direct loading from commercial mixtures. MS-based proteomics will offer an insight into the molecular mechanisms of toxicity and potential developmental and neurotoxicity of PBDEs.

Polybrominated diphenyl ethers (PBDEs) in Mediterranean mussels (Mytilus galloprovincialis) from selected Apulia coastal sites evaluated by GC-HRMS

Samples of Mytilus galloprovincialis were examined to investigate the levels of polybrominated diphenyl ethers (PBDEs) in the Apulia's marine environment, a region in the South of Italy. The levels of nine PBDE congeners were measured in 40 mussel samples taken from the aquaculture farms in the South of Adriatic Sea and North Ionian Sea along the Apulia coast. While accelerated solvent extraction (ASE) was the extraction technique adopted using acetone/n-hexane (1:1, v/v), the content of PBDEs was evaluated by using gas chromatography coupled with high-resolution mass spectrometry (GC-HRMS) via electron ionization (EI) in the multiple ion monitoring (MIM) mode (two ions for each compound). The (13)C mass-labeled compounds were used to establish the levels of PBDEs in M. galloprovincialis samples. The total concentration of PBDEs (ΣPBDEs) ranged from 0.2 to 6.9 ng/g dry mass, with the highest concentrations found around coastal areas of Salento. With regard to the composition of PBDE congeners, BDE-47, BDE-99 and BDE-100 were the predominant congeners in most of the samples. The present study is the first to report levels of PBDEs occurring in aquatic organisms living in aquaculture farms of Apulia region.

Potential of atmospheric pressure chemical ionization source in GC-QTOF MS for pesticide residue analysis

The potential applications of a new atmospheric pressure source for GC-MS analysis have been investigated in this work. A list of around 100 GC-amenable pesticides, which includes organochlorine, organophosphorus and organonitrogenated compounds, has been used to evaluate their behavior in the new source. Favoring the major formation of the molecular ion in the source has been the main goal due to the wide-scope screening possibilities that this fact brings in comparison with the traditional, highly fragmented electron ionization spectra. Thus, the addition of water as modifier has been tested as a way to promote the generation of protonated molecules. Pesticides investigated have been classified into six groups according to their ionization/fragmentation behavior. Four of them are characterized by the abundant formation of the protonated molecule in the atmospheric pressure source, mostly being the base peak of the spectrum. These results show that wide-scope screening could be easily performed with this source by investigating the presence of the protonated molecule ion, MH+. The developed procedure has been applied to pesticide screening in different food samples (nectarine, orange and spinach) and it has allowed the presence of several pesticides to be confirmed such as chlorpyriphos ethyl, deltamethrin and endosulfan sulfate. The availability of a quadrupole time-of-flight instrument made it feasible to perform additional MS/MS experiments for both standards and samples to go further in the confirmation of the identity of the detected compounds. Results shown in this paper have been obtained using a prototype source which exhibits promising features that could be applied to other analytical problems apart from those illustrated in this work.

Thyroid disruption by technical decabromodiphenyl ether (DE-83R) at low concentrations in Xenopus laevis

Decabromodiphenyl ether (decaBDE), as a flame retardant, is widely produced and used. To study the thyroid disruption by technical decaBDE at low concentrations, Xenopus laevis tadpoles were exposed to technical decaBDE mixture DE-83R (1-1000 ng/L) in water from stage 46/47 (free swimming larvae, system of Nieuwkoop and Faber) to stage 62. DE-83R at concentration of 1000 ng/L significantly delayed the time to metamorphosis (presented by forelimb emergence, FLE). Histological examination showed that DE-83R at all tested concentrations caused histological alterations - multilayer follicular epithelial cell and markedly increased follicle size accompanied by partial colloid depletion and increase in the peripheral colloid vacuolation, in thyroid glands. All tested concentrations of DE-83R also induced a down-regulation of thyroid receptor mRNA expression. These results demonstrated that technical decaBDE disrupted the thyroid system in X. laevis tadpoles. Analysis of polybrominated diphenyl ethers (PBDEs) (sum of 39 congeners) in X. laevis indicated that mean concentrations of total PBDEs in X. laevis exposed to 1, 10, 100, 1000 ng/L were 11.0, 128.1, 412.1, 1400.2 ng/g wet weight, respectively. Considering that PBDEs burden ofX. laevis tadpoles was close to PBDEs levels in amphibians as reported in previous studies, our study has raised new concerns for thyroid disruption in amphibians of technical decaBDE at environmentally relevant concentrations.

Searching for anthropogenic contaminants in human breast adipose tissues using gas chromatography-time-of-flight mass spectrometry

The potential of gas chromatography-time-of-flight mass spectrometry (GC-TOF MS) for screening anthropogenic organic contaminants in human breast adipose tissues has been investigated. Initially a target screening was performed for a list of 125 compounds which included persistent halogen pollutants [organochlorine (OC) pesticides, polychlorinated biphenylss (PCBs), polybrominated diphenyl ethers (PBDEs)], polyaromatic hydrocarbons (PAHs), alkylphenols, and a notable number of pesticides from the different fungicide, herbicide and insecticide families. Searching for target pollutants was done by evaluating the presence of up to five representative ions for every analyte, all measured at accurate mass (20-mDa mass window). The experimental ion abundance ratios were then compared to those of reference standards for confirmation. Sample treatment consisted of an extraction with hexane and subsequent normal-phase (NP) High performance liquid chromatography (HPLC) or SPE cleanup. The fat-free LC fractions were then investigated by GC-TOF MS.Full-spectral acquisition and accurate mass data generated by GC-TOF MS also allowed the investigation of nontarget compounds using appropriate processing software to manage MS data. Identification was initially based on library fit using commercial nominal mass libraries. This was followed by comparing the experimental accurate masses of the most relevant ions with the theoretical exact masses with calculations made using the elemental composition calculator included in the software.The application of both target and nontarget approaches to around 40 real samples allowed the detection and confirmation of several target pollutants including p,p'-DDE, hexachlorobenzene (HCB), and some polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). Several nontarget compounds that could be considered anthropogenic pollutants were also detected. These included 3,5-di-tert-butyl-4-hydroxy-toluene (BHT) and its metabolite 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHT-CHO), dibenzylamine, N-butyl benzenesulfonamide (N-BBSA), some naphthalene-related compounds and several PCBs isomers not included in the target list. As some of the compounds detected are xenoestrogens, the methodology developed in this paper could be useful in human breast cancer research.