Selective Pressurized Liquid Extraction Research Articles

Development of a Methodology for Determination of Dioxins and Dioxin-like PCBs in Meconium by Gas Chromatography Coupled to High-Resolution Mass Spectrometry (GC-HRMS)

An analytical strategy was applied to investigate polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in newborn meconium samples. The methodology includes extraction by selective pressurized liquid extraction (SPLE), followed by a clean-up multicolumn step. The samples were injected by gas chromatography coupled to a high-resolution mass spectrometer (GC-HRMS). The surrogate recoveries ranged from 68% to 95%, and the average of the limit of quantification (LOQ) ranged from 0.03 to 0.08 pg g−1 wet weight (ww) for PCDD/Fs and 0.2 to 0.88 pg g−1 ww for dl-PCBs. The strategy was applied to 10 samples collected in Valencia (Spain) in 2022. In total, 18 out of 29 analysed congeners were detected in at least one sample, whereas 6 of them were detected in all the samples (OCDD, PCB-123, PCB-118, PCB-105, PCB-167, and PCB-156). The levels for the sum of the 17 congeners of PCDD/Fs and 12 congeners of dl-PCBs in the upper-bound (UB), expressed as picograms of toxic equivalency quantity (TEQ) per gram of ww, ranged from 0.19 to 0.31 pg TEQ g−1 ww.

Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

A method of quantification of perfluorinated compounds (PFCs) from atmospheric particulate matter (APM) is described. A single step pretreatment method, selective pressurized liquid extraction (SPLE), was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment steps. An effective sorbent was selected to purify the PFCs during SPLE, followed by liquid chromatography-tandem mass spectrometry (LC–MS/MS), for quantification of PFCs. Conditions affecting the SPLE efficiency, including temperature, static extraction time, and number of extraction cycles used, were studied. The optimum conditions were found to be 120°C, 10 min, and 3 cycles, respectively. LC-MS/MS method was developed to obtain the optimal sensitivity specific to PFCs. The method detection limits (MDLs) were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/g. To ensure accurate values were obtained, each step of the experiment was evaluated and controlled to prevent contamination. The optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target compounds. Finally, the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to 2019. It is observed that some PFCs follow the trend of total PFC changes, and can be attributed to the environment influencing events and policy enforcement, while others don't seem to change as much with time of the year or from year to year.

Optimization of Pressurized Liquid Extraction and In Vitro Neuroprotective Evaluation of Ammodaucus leucotrichus. Untargeted Metabolomics Analysis by UHPLC-MS/MS.

Ammodaucus leucotrichus is a spontaneous plant endemic of the North African region. An efficient selective pressurized liquid extraction (PLE) method was optimized to concentrate neuroprotective extracts from A. leucotrichus fruits. Green solvents were tested, namely ethanol and water, within a range of temperatures between 40 to 180 °C. Total carbohydrates and total phenolics were measured in extracts, as well as in vitro antioxidant capacity (DPPH radical scavenging), anticholinesterase (AChE) and anti-inflammatory (LOX) activities. Metabolite profiling was carried out by ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry (UHPLC-ESI-q-TOF-MS/MS), identifying 94 compounds. Multivariate analysis was performed to correlate composition with bioactivity. A remarkable effect of the temperature using water was observed: the higher temperature, the higher extraction yield, the higher total phenolic content, as well as the higher total carbohydrates content. The water extract obtained at 180 °C, 10.34 MPa and 10 min showed meaningful anti-inflammatory (IC50LOX = 39.4 µg/mL) and neuroprotective activities (IC50AChE = 55.6 µg/mL). The Principal Components Analysis (PCA) and the cluster analysis correlated these activities with the presence of carbohydrates and phenolic compounds.

Analysis of Dechlorane Plus and related compounds in gull eggs by GC-HRMS using a novel atmospheric pressure photoionization source

Here, a new gas chromatography-atmospheric pressure photoionization-high-resolution mass spectrometry (GC-APPI-HRMS) method combined with selective pressurized liquid extraction (sPLE) has been developed for the selective determination of Dechlorane Plus (DP) and its related compounds in gull egg samples used as a bioindicator of contamination. To the best of our knowledge, this is the first time these compounds have been analyzed by GC-MS using atmospheric pressure photoionization (APPI). Negative ion dopant-assisted APPI using vapors of diethyl ether and a source temperature of 250°C provided high ionization efficiencies and mass spectra characterized by intense in-source fragment ions as well as the presence of molecular ion and characteristic cluster ions containing oxygen atoms in their chemical structure. This made it possible to improve the selectivity in the determination of these compounds compared to that obtained with traditional GC-MS ion sources. Under optimized conditions, the sPLE GC-APPI-HRMS (Orbitrap) method provided high recoveries (> 91%), good precisions (RSD% < 12%), and low method limits of detection (0.1-3.5pgg-1 wet weight). The developed methodology has been applied to the determination of DP and related compounds in eggs of two gull species (L. michahellis and L. audouinii) from several Spanish protected areas. The results obtained showed significant differences in the DP concentration profiles in eggs from different gull breeding locations and between gull species of the same protected area. These results demonstrated the good performance of the GC-APPI-HRMS system to achieve a selective and sensitive determination of DP and related compounds in complex environmental samples.

Association between placenta concentrations polybrominated and polychlorinated biphenyls and gestational diabetes mellitus: a case-control study in northwestern Spain.

Exposure to persistent organic pollutants begins in uterine life. The study was conducted to evaluate associations between gestational diabetes mellitus and the presence of persistent organic pollutants in placenta samples. They were derived from a birth cohort study in Ourense (NW Spain). Selective pressurized liquid extraction methodologies were used to determine targeted persistent organic pollutants in placenta samples. Cleanup of extracts was performed by solid-phase extraction using EZ-POP cartridges and detection by gas chromatography coupled to tandem mass spectrometry. Statistical calculations were performed by comparing the values obtained in the case and control groups. Statistical significance was considered as p < 0.050. Results: The concentrations of several congeners of polybrominated diphenyl ethers (PBDE) and polychlorinated biphenyls (PCB) presented lower levels in the placentas of expectant mothers with gestational diabetes mellitus when comparing them to the control cohort. This difference was statistically significant. It was revealed that this association was independent of obesity, age, parity, amenorrhoea at birth, or a family history of diabetes mellitus. To the best of our knowledge, this paper reported an inverse relationship between PBDE and PCB levels in placenta and gestational diabetes mellitus for the first time. We believe this may open a door to future studies in this field.

Optimization of a new selective pressurized liquid extraction methodology for determining organic pollutants in wild boar livers

In this study, a new selective pressurised liquid extraction (SPLE) methodology was optimised for determining about 70 organic pollutants (OPs) including organochlorine (OCPs), organophosphate (OPPs) and pyrethroid (PYRs) pesticides, polychlorinated biphenyls (PCBs), polybromodiphenyl ethers (PBDEs), as well as, polycyclic aromatic hydrocarbons (PAHs) in wild boar liver samples considering the temperature, pressure and time of contact between the solvent and the matrix as influential variables. Clean-up of extracts was performed by solid-phase extraction (SPE) using EZ-POP cartridges. Detection of OPs was carried out by gas chromatography (GC) coupled to tandem mass spectrometry (QqQ-MS/MS). This new approach offers:•A new non-time consuming SPLE methodology for determining about 70 OPs in wild boar.•Recoveries achieved ranged between 74 to 119 % with RSD less than 20 %.•Detection and quantification limits in the low to mid pg/g range.

Wild boar (Sus scrofa) as bioindicator for environmental exposure to organic pollutants

Organic pollutants (OPs) are widely distributed around the globe, their presence has become an issue of great concern in the last years due to their potential health effects. Wildlife biomonitoring of OPs has been nowadays a common approach to assess chemical exposure in wildlife and humans. In a sample of 60 wild boars (Sus scrofa) from NW Spain, we evaluated the suitability of using liver and hair samples for the assessment of exposure and bioaccumulation of polychlorinated biphenyls (PCBs) including dioxin and non-dioxin like PCBs (DLPCBs and NDLPCBs), organochlorine and organophosphate pesticides (OCPs and OPPs, respectively), polybromodiphenyl ethers (PBDEs), pyrethroids (PYRs) and polycyclic aromatic hydrocarbons (PAHs). Selective pressurized liquid extraction (SPLE) and liquid-liquid extraction (LLE) methodologies were used to determine the target OPs in liver and hair samples. Clean-up of extracts was performed by solid-phase extraction (SPE) using EZ-POP cartridges and detection by gas chromatography coupled to tandem mass spectrometry (GC-QqQ-MS/MS). We found a distribution pattern of ΣPAHs > ΣOCPs > ΣPYRs > ΣNDLPCBs > ΣOPPs > ΣDLPCBs > ΣPBDEs in liver and of ΣPAHs > ΣOCPs > ΣNDLPCBs > ΣPYRs > ΣOPPs > ΣDLPCBs > ΣPBDEs in hair. Significant correlations (p < 0.050) between the socio-demographic characteristics (gender, age and place) and OP concentrations of OCPs, PBDEs, PYRs, OPPs and PAHs were detected. Moderate correlation was found between HCB, PCB28, PCB157 and chlorpyrifos contents in both hair and liver samples. On the basis of these results, our data shows the correlation and complementary information given by both biological samples.

Brominated flame retardants (BFRs) in Western Australian biosolids and implications for land application

This study evaluates the prevalence of eight priority polybrominated diphenyl ethers (PBDEs; −28, −47, −99, −100, −153, −154, −183 and −209) and six novel brominated flame retardants (NBFRs; pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenyl ethane (DBDPE)) in biosolids samples from 15 wastewater treatment plants (WWTPs) in Western Australia. Analytes were extracted using selective pressurized liquid extraction (S-PLE) and quantified by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) operated in electron impact (EI) ionization mode. ∑8PBDE levels in biosolids ranged from 11 to 18,000 μg/kg dw with a median concentration of 1800 μg/kg dw. BDE-209 was the most prevalent congener constituting a median of 98% of ∑8PBDE concentrations in samples with BDE-99, -47 and −100 each typically contributing less than 3% to total levels. NBFRs were detected in 71% of samples with ∑6NBFR levels ranging between ND-1100 μg/kg dw (median; 600 μg/kg dw). Levels of DBDPE greatly exceeded those of all other NBFRs, while the next most prevalent compounds were EH-TBB and HBB. Australia produced approximately 327,000 dry tonnes of biosolids in 2017, of which approximately 75% was beneficially utilized on farmland as a fertilizer. Based on these results, an estimated 440 kg of BDE-209 and 150 kg of DBDPE are applied to agricultural land via biosolids applications annually in Australia. This study provides the first account of NBFR concentrations in Australian biosolids.

Comparison of ultrasound-assisted extraction, QuEChERS and selective pressurized liquid extraction for the determination of metabolites of parabens and pharmaceuticals in sludge

Analytical methods for the determination of parabens and pharmaceuticals in sludge are scarce and focused on the parent compounds in spite that metabolites can be more toxic and concentrated. This fact is of special relevance when sewage sludge is applied as soil fertiliser what is a common practise in many European countries. In that way, they could affect soils and plants and could even enter into the food chain. In this work, to cover the lack of methodologies for the determination of metabolites of parabens and pharmaceuticals in sludge, two analytical methods have been developed. Proposed analytical methods are based on low-cost and easy-to-perform techniques (ultrasonic-assisted extraction (UAE) and QuEChERS) to make them affordable for routinely control laboratories. The methods have been optimised and validated for the determination of 12 relevant metabolites of parabens and pharmaceuticals and their 7 parent compounds. Proposed methods have been compared with a previously reported method based on selective pressurised liquid extraction (SPLE). UAE method provided higher recoveries, lower MQL, higher precision and higher accuracy than QuEChERS method. Nevertheless, both QuEChERS and UAE methods, in spite of being more time-consuming and difficult to automatise, have been demonstrated to be suitable low-cost alternatives to SPLE. To the best of our knowledge, UAE, QuEChERS and SPLE proposed methods constitute the first multiresidue methods for the simultaneous determination of metabolites of parabens and pharmaceuticals in sewage sludge.

Prenatal exposure to organic pollutants in northwestern Spain using non-invasive matrices (placenta and meconium)

Human exposure to environmental organic pollutants (OPs) begins in the uterine life period by trans-placental transfer. Epidemiological studies have consistently demonstrated the vulnerability of human fetuses and infants to the effects of OPs because of their rapid growth and organ development, cell differentiation, and immaturity of metabolism. The aim of the present study was to evaluate the prenatal exposure to OPs characterized by different physicochemical properties using non-invasive biological samples (meconium and placenta). A total of 88 placenta and 53 meconium samples were collected in Ourense, a city located in northwestern Spain, at the delivery and after birth from mothers and their infants from the University Hospital of Ourense, respectively. Selective pressurized liquid extraction (SPLE) methodologies were used to determine the targeted OPs in the selected biological samples. Cleanup of extracts was performed by solid-phase extraction (SPE) using EZ-POP cartridges and detection by gas chromatography (GC) coupled to tandem mass spectrometry (QqQ-MS/MS). The targeted OPs were detected with the following mean level total concentration order polycyclic aromatic hydrocarbons (PAHs) > organophosphorus pesticides (OPPs) > non-dioxin like polychlorinated biphenyls (NDLPCBs) > pyrethroids (PYRs) > polybrominated diphenyl ethers (PBDEs) > dioxin like polychlorinated biphenyls (DLPCBs) > organochlorine pesticides (OCPs) for placenta and ΣNDLPCBs > ΣPAHs > ΣOCPs > ΣPYRs > ΣOPPs > ΣDLPCBs > ΣPBDEs for meconium, respectively. Significant correlations (p < .050) between the socio-demographic characteristics of the selected population (mother's parity, age, weight increase during pregnancy, place of living and smoking habits) and log transformed concentration of some of the targeted OPs (OCPs, PBDEs, PYRs, OPPs and PAHs) were detected. The results obtained shown the complementary information given by both biological samples selected. Nevertheless, additional research will be needed to gain an understanding of the trans-placental transfer of OPs, to choose the best biological matrix to evaluate the prenatal exposure to OPs in a correct way and to know their health implications.

Adélie penguin colonies as indicators of brominated flame retardants (BFRs) in East Antarctica

While persistent organic pollutant (POP) contamination within Antarctica is largely caused by long-range atmospheric transport (LRAT), Antarctic research bases have been shown to be local sources of POPs such as brominated flame retardants (BFRs). This study compared concentrations of seven polybrominated diphenyl ethers (PBDE) congeners and five novel flame retardants (NBFRs) found in Adélie penguin (Pygoscelis adeliae) colony soils near the Australian research stations, Mawson and Davis, to assess the stations as local sources of these contaminants and provide a much needed baseline for contamination of BFRs in East Antarctica. Soil samples (n = 46) were collected from Adélie colonies at close proximity to the research stations as well as further afield during the 2016-17 austral summer. Samples were analysed using selective pressurised liquid extraction (S-PLE) and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). PBDEs (BDE-28, -47, -99, -100, -153, -154 and -183) were detected in 45/46 samples with ∑7PBDE concentrations ranging from <0.01 to 1.63 ng/g dry weight (dw) and NBFRs (2,3,4,5,6-pentabromotoluene (PBT), 2,3,4,5,6-pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis(2,4,6-tribromophenoxy) ethane (BTBPE)) detected in 20/46 samples, with a range of ∑5NBFR from not detected (ND) to 0.16 ng/g dw. Soils taken from around the Davis and Mawson research stations were more highly contaminated (n = 10) than penguin colonies (n = 27) and control areas not affiliated with breeding seabirds (n = 8). The most common congener detected was BDE-99, reflecting inputs from LRAT. However, the congener profiles of station soils supported the hypothesis that research stations are a local source of PBDEs to the Antarctic environment. In addition, the NBFR pentabromoethylbenzene (PBEB) was quantified for the first time in Antarctic soils, providing essential information for baseline contamination within the region and highlighting the need for ongoing monitoring as global regulations for the use of BFRs continuously change.

Selective pressurized liquid extraction of plant secondary metabolites: Convallaria majalis L. as a case

A fast and efficient selective pressurized liquid extraction (sPLE) method was developed to extract secondary metabolites from complex plant matrix. Convallaria majalis L., a plant producing toxic steroids, was used as proof-of-concept. The method was optimized in the aspects of preheating, dispersant, extraction temperature and solvent, and the use of C18 as in-cell cleanup sorbent. Eight authentic natural steroids with diverse sugar moieties and hydrophobicities were selected as reference analytes and spiked to 0.1 g dried leaves. The extraction performance was evaluated based on the analytes’ stability, recovery, matrix effect in the electrospray interface and the level of co-extractives. With the optimal method, the extraction was finished in 10 min. A colorless extract was obtained with recoveries ranging from 63% to 107% and absolute matrix effects ranging from 3% to 27%. The optimized method was validated by extracting 0.1 g, 0.2 g and 0.4 g spiked plant samples; method accuracy and precision were assessed by recoveries and relative standard deviations of the combined extraction-analysis workflow. The method was also tested on soil samples and indicated its suitability for measuring secondary metabolites in multiple environmental matrices. To our knowledge, this is the first time sPLE has been reported to extract plant secondary metabolites from a complex plant matrix, with satisfactory recoveries and low matrix effects. This is also the first time (s)PLE has been reported to extract plant secondary metabolites from soil. We envision the method be coupled with liquid chromatography-electrospray ionization-high resolution mass spectrometry in a standard metabolomics workflow to facilitate plant metabolomics studies.

Selective pressurized extraction as single-step extraction and clean-up for the determination of organophosphate ester flame retardant in Citrus aurantium leaves by gas chromatography-tandem mass spectrometry.

In this work, an analytical method has been developed and validated for the determination of organophosphate esters (OPEs) in urban ornamental tree leaves. OPEs are flame retardants and plasticizers which are classified as health and environmental hazards substances. Their presence in urban air has been previously described. The method proposed in this work would allow the use of urban tree leaves as simple, cheap, and widely distributed in urban areas alternative to the existing active and passive sampler for sample collection. The method was based on sample treatment by selective pressurized liquid extraction (SPLE) and determination by gas chromatography with triple quadrupole mass spectrometry detector. After the optimization of the extraction solvent, the key parameters applied to SPLE (clean sorbent and sorbent amount applied for the sample clean-up, temperature, extraction cycles, and time) were optimized using a Box-Behnken response surface design. The method achieves high recoveries (higher than 60% for most of the target compounds), accuracies between 70 and 109%, and method detection and quantification limits ranged 0.05-4.96ng/g dw (dry weight) and 0.15-14.4ng/g dw, respectively. The method allowed the proper biomonitoring of OPE in tree leaves. Concentrations measured in analyzed samples were from 47.5 to 5477ng/g dw (TEP). The most frequently detected compounds were triethyl phosphate tri-n-butyl phosphate, triphenyl phosphate, and tris(1-chloro-2-propyl)phosphate, while tris(2-ethylhexyl)phosphate was not detected in the analyzed samples. The proposed analytical method constitutes a starting point for the use of ornamental urban trees as passive sampler for the evaluation of OPE as air pollutants. Graphical Abstract.

Rapid extraction method of polycyclic aromatic compounds in soil using basic silica selective pressurized liquid extraction

Complex chemical mixtures found in soils at contaminated sites typically includes polycyclic aromatic compounds (PACs), thus posing potential environmental and human health risks. Pressurized liquid extraction (PLE) followed by silica clean-up is one of the most often used extraction methods for PACs in soil. While silica clean-up provide satisfactory recovery of oxygenated polycyclic aromatic hydrocarbons (OPAHs), this technique provides limited recovery of azaarenes. In this work, we used PLE and in-cell clean up with basic silica to increase the recovery of OPAHs and azaarenes. The optimized selective pressurized liquid extraction (SPLE) method used 4 g basic silica, dichloromethane, 100% flush volume, 100 and 120 °C extraction temperatures, with two static cycles for each temperature, no rinse in between the two extractions, and 20 and 120 s purge for the first and second extraction temperature, respectively. The method was validated for a wide range of PAC groups, including OPAHs, azaarenes, alkylated PAHs, and sulfur heterocycles (SPACs), in total 87 PACs, using certified reference material and in comparison to the results from previous inter-laboratory data. Our SPLE method yielded results that are in agreement with certified values and inter-laboratory data from prior analysis. The SPLE method also yielded lower variation than the results from the inter-laboratory data for analysis of OPAH and azaarenes, suggesting better precision than previous methods. More importantly, the SPLE method increases sample analysis throughput as extra clean-up step is not necessary anymore. The SPLE method was then successfully applied to rapidly screen PACs in three soil samples.

Simultaneous pressurized liquid extraction and clean-up for the determination of metabolites in complex environmental solid matrices

Parabens and pharmaceuticals are two of the most significant groups of pollutants of emerging concern. Nevertheless, in spite that their presence in the environment is well-known, to the date, there is scarce information about the presence of their metabolites that can be present at higher concentrations in the environment, be more toxic and be transformed into the parent compound. In this work, an analytical method has been developed and validated for the first-time simultaneous determination of metabolites of methyl- and propylparabens, caffeine, carbamazepine, diclofenac, ibuprofen and sulfamethoxazole and their parent compounds in soil, compost and digested sludge. Box-Behnken experimental design was applied for method optimisation due to the high number of experimental variables to optimize and the different physical-chemical properties of the target compounds. The method involves simultaneous sample extraction and clean-up by selective pressurized liquid extraction and analytical determination in a single run by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Good linearity, accuracy (mainly from 80 to 112%) and precision (<11%) was obtained. Method quantification limits were in the range from 0.12 to 14.4 ng g−1 dry matter. The application of the method to soil, compost and digested sludge revealed that metabolites of parabens, carbamazepine, diclofenac and ibuprofen were at similar or higher concentrations than their parent compounds in digested sludge and the presence of metabolites of parabens, caffeine and carbamazepine in compost.

Determination of toxic organic pollutants in fine particulate matter using selective pressurized liquid extraction and gas chromatography–tandem mass spectrometry

Studies investigating toxic organic pollutants in fine dust (PM2.5), such as polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), are insufficient, despite the pollutants’ potent toxicity. The objective of this study is to develop an analytical method for determining PAHs, OCPs and PCBs in ambient PM2.5 using selective pressurized liquid extraction (SPLE). To maximize the extraction efficiency of target analytes, the extraction parameters of SPLE, particularly solvent type, temperature, static time, and cycle number, were optimized. The highest recoveries were observed under the conditions of dichloromethane:acetone (9:1), 100℃, 5 min of static time, and 1 cycle extraction, which is selected as the optimal method of SPLE. In the method validation, the results showed that the suggested method can quantify 17 PAHs, 20 OCPs, and 63 PCBs in PM2.5. Using urban dust SRM (1648a) and ambient PM2.5 samples, the applicability of the method was also confirmed. Total concentration of PAHs was the highest (2639.42–7377.75 pg/m3) followed by OCPs (80.57–674.69 pg/m3) and PCBs (1.39–9.34 pg/m3). Most of the PAHs were detected, whereas 2–7 compounds among 20 OCPs and 2–6 compounds among 63 PCBs were determined. The developed analytical method is highly efficient in terms of process (a one-step extraction process), time (15 min extraction time per one sample) and solvent usage (less than 30 mL per one sample), showing good performance. This method can be applied to investigate the organic toxicants in PM2.5, and it can contribute to monitoring and risk assessment, leading to an effective risk management policy for PM2.5 in Korea.

Concentrations of legacy and novel brominated flame retardants in indoor dust in Melbourne, Australia: An assessment of human exposure

Polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFR) have been used in a range of polymers to inhibit the spread of fires but also have a propensity to migrate out of consumer materials and contaminate indoor dust. In this study, a total of 57 dust samples were collected from 12 homes, eight offices and eight vehicles in Melbourne, Australia and analysed for eight PBDEs (-28, -47, -99, -100, -153, -154, -183 and -209) and seven NBFRs (PBT, PBEB, HBB, EH-TBB, BEH-TEBP, BTBPE and DBDPE) to determine human exposure risks from dust ingestion. Samples were analysed using selective pressurized liquid extraction (S-PLE) and gas chromatography coupled to tandem mass spectrometry (GC–MS/MS). Legacy and replacement flame retardants were detected in all samples with overall ∑PBDE concentrations ranging from 120 to 1700,000 ng/g (median 2100 ng/g) and ∑NBFRs ranging from 1.1 to 10,000 ng/g (median 1800 ng/g). BDE-209 and DBDPE were the dominant compounds in dust samples, followed by congeners associated with commercial Penta-BDE formulations (-47, -99, -100, -153 and -154) and then EH-TBB of the FireMaster 550 and BZ-54 products. ∑Penta-BDE concentrations were elevated in office samples compared with homes and vehicles, while EH-TBB and BDE-209 measured higher concentrations in vehicles compared with their respective levels in homes and offices. Risk assessment estimates revealed the majority of exposure to occur in the home for both adults and toddlers in the City of Melbourne. Generally, body weight adjusted exposure to PBDEs and NBFRs was predicted to be 1 to 2 orders of magnitude higher for toddlers than adults. Estimated rates of BDE-47, -99, -153 and -209 ingestion were each 2 orders of magnitude or more below the USEPA's prescribed oral reference dose values (RfDs) for typical exposure scenarios. However, exposure rates for BDE-47 and -99 reached as high as 52 and 95% of RfDs, respectively, for adults and 4.4 and 7.4%, respectively, for toddlers in high exposure scenarios. This study provides the first wide-ranging survey of NBFRs in indoor dust from homes, offices and vehicles in Australia and offers further evidence of human exposure to legacy and novel brominated flame retardants via dust ingestion.

Determination of brominated diphenyl ethers in atmospheric particulate matter using selective pressurized liquid extraction and gas chromatography–mass spectrometry with a negative chemical ionization

This study describes the development and validation of a sensitive and reliable method for determination of polybrominated diphenyl ethers (PBDEs) in atmospheric particulate matter using selective pressurized liquid extraction (SPLE) and gas chromatography–mass spectrometry with a negative chemical ionization (GC-NCI-MS). Extraction and clean-up were performed using PLE with 2 g florisil and 3 g silica placed in the extraction cells. Under optimal conditions, 14 PBDEs were extracted at 70 °C using hexane/dichloromethane (50:50, v/v) as solvent. Validation of SPLE returned excellent recoveries for most analytes, with relative standard deviations mostly below 20%. Method detection limits ranged from 0.13 to 15.38 ng·mL−1 for the GC-MS analyses. The method was successfully applied to atmospheric particulate matter of Beijing, where analytes were detected in the range of 182.79 to 468.99 pg·m−3.

Methodology for non-target screening of sewage sludge using comprehensive two-dimensional gas chromatography coupled to high-resolution mass spectrometry

To investigate the wide range of pollutants occurring in sewage sludge, an analytical method for comprehensive non-target screening is needed. To the best of our knowledge, no procedures currently exist for the full screening of organic contaminants in sewage sludge, which is the ultimate goal of this project. We developed non-discriminating sample preparation methods for gas chromatography-mass spectrometry (GC-MS) analysis. Pressurized liquid extraction (PLE) was used for extraction, with in-line (silica gel selective PLE, SPLE) or off-line clean-up (gel permeation chromatography, GPC). This combination allowed the analysis of non-polar compounds of all sizes and small semi-polar and non-polar compounds. The results show that the combination of SPLE and PLE with GPC is suitable for analysis of established as well as new contaminants. Both methods were validated for 99 compounds with different properties. For all GC suitable analytes, either one of the methods produced acceptable recoveries (64 to 136%). As a test, the two methods were used for non-target screening of Swedish sewage sludge. A tiered approach was used to tentatively identify the sludge contaminants. In total, 1865 and 1593 compounds were found of which 321 and 192 compounds were tentatively identified for the PLE and SPLE method, respectively. For a comprehensive coverage of contaminants, the two methods should be used together, with the PLE method covering a wider polarity range and the SPLE method a wider size range. In addition, polar substances will require liquid chromatography-mass spectrometry analysis, the method for which will be developed soon.

Optimization of selective pressurized liquid extraction of organic pollutants in placenta to evaluate prenatal exposure

The early exposure to organic pollutants (OPs) related to dietary habit or environmental exposure is a concern of growing interest in environmental health. When OPs enter the body, they can accumulate in fatty tissue and even travel through the bloodstream being able to cross the placenta and reach the fetus through the substance exchange between the mother and the child. Epidemiologic and clinical data affirm that these chemicals increase the risk of adverse effects during childhood. This article reviews and addresses one of the most relevant analytical methods for determining OPs in placenta. We discuss and critically evaluate procedures, such as solid-liquid and selective pressurized liquid extraction (SPLE). Clean-up of extracts was performed by solid-phase extraction (SPE) using EZ-POP cartridges. Detection of OPs was carried out by gas chromatography (GC) coupled to tandem mass spectrometry (MS/MS). Recoveries ranged from 52% to 94% by SPLE with estimated quantification limits between 0.15 and 2.2ng/g for organochlorine pesticides (OCPs), between 0.083 and 0.50 for organophosphate pesticides (OPPs), between 0.025 and 0.15ng/g for polychlorinated biphenyl (PCBs), between 0.015 and 0.10ng/g for polybromodiphenyl ethers (PBDEs), between 0.33 and 0.66ng/g for pyrethroids and between 0.022 and 0.87ng/g for polycyclic aromatic hydrocarbons (PAHs). Most of the target OPs were detected in twenty real placenta samples studied, with pyrethroids, PAHs and OPPs representing most of the 90% of OPs with means of 13–18ng/g versus PCBs, OCPs, and PBDEs with means <4.0ng/g. The rsults of this work indicate a prenatal exposure to OPs in Galicia.