Determination Of Polychlorinated Biphenyls Research Articles

Determination of PCB and PAH tissue levels in bottlenose dolphins that stranded in the Mississippi sound before and after the unusual mortality event in 2019

Cetaceans are regarded as a sentinel species because their health and population changes can serve as indicators of effects on marine ecosystems. We characterized levels of 24 polycyclic aromatic hydrocarbons (PAHs) and 7 polychlorinated biphenyls (PCBs) in blubber, kidney, liver, and muscle of 138 bottlenose dolphins (Tursiops truncatus) that stranded in the Mississippi Sound (MSS) between 2010 and 2021. The samples were divided into four time periods: 2010–2018, 2019, 2020, and 2021, to assess whether there was a significant association between chemical levels in dolphin tissues and the 2019 unusual mortality event (UME) in the MSS resulting from the unprecedented freshwater incursion from 2 openings of the Bonnet Carré Spillway (BCS). We found 7 PCBs were readily detected in all tissues across time, and the major PAH was naphthalene, with detection of biphenyl and acenaphthene at lower levels and frequency. There was little change in tissue PCB levels over time; only naphthalene in the blubber was higher in tissues from dolphins that stranded before 2019. However, there were not significant changes in chemical levels in tissues from stranded bottlenose dolphins in the MSS before or after the UME in 2019.

Development and validation of a gas chromatography method for analysing polychlorinated biphenyls in fish roe

A method for determining polychlorinated biphenyls (PCBs) in fish roe by gas chromatography (GC) has been developed. The suitability (validation) of the process for the determination of 14 PCBs (PCB 18, PCB 31, PCB 28, PCB 52, PCB 44, PCB 101, PCB 149, PCB 118, PCB 153, PCB 138, PCB 180, PCB 170, PCB 194, PCB 209) in fish roe by GC using an electron capture detector (ECD) was evaluated according to the following criteria: selectivity, linearity, limits of detection (LOD), limits of quantification (LOQ), accuracy and precision. Automated Soxhlet extraction and sample clean-up by solid phase extraction (SPE) were proposed for extracting PCBs from fish roe. The results of the method selectivity study showed that the determination of PCBs in fish roe is not affected by other components in the sample. The correlation coefficients for fourteen PCBs ranged from 0.9962 to 0.9999 (R2 ≥0.995). The limits of detection (LOD) and limits of quantification (LOQ) of PCBs are below the maximum permissible levels set by the European Union (EU). The recovery percentage ranged from 81.5% to 107%, indicating the PCB extraction procedure's acceptability (R, 80 – 120%). The relative standard deviation (RSD, %) of the measurement results under convergence conditions ranged from 1.02% to 9.43% (RSD ≥15%). The obtained method suitability (validation) data meets the Commission Regulation (EU) No 589/2014 criteria.

Methyltrimethoxysilane modified tin dioxide microspheres with hydrophobic networks and abundant adsorbed oxygen for efficient solid-phase microextraction of polychlorinated biphenyls.

Methyltrimethoxysilane (MTMS) modified tin dioxide microspheres (MTMS/SnO2) were prepared by a facile hydrothermal method and heated reflux reaction strategy. The characterization results indicate that the modification of MTMS induced the formation of a hydrophobic network within the composites, while maintaining abundant adsorbed oxygen species. Subsequently, the MTMS/SnO2 microspheres were used as a solid-phase microextraction (SPME) coating for the efficient extraction and sensitive determination of trace polychlorinated biphenyls (PCBs) in aqueous solutions coupled to gas chromatography-mass spectrometry. MTMS/SnO2 coating exhibited superior extraction performances for PCBs compared withcommercial SPME and pure SnO2 microspheres coatings, owing to the hydrophobic crosslinking and adsorbed oxygen-enhanced hydrogen bonding. The proposed analytical method presented respectable linearity in the concentration range 0.25-1000ng L-1, with low limits of detection varying from 0.036 to 0.14ng L-1 for seven PCBs and excellent precision, with relative standard deviations of 5.7-9.8% for a single fiber and 8.2-13.1% for five fibers. Finally, the proposed method was successfully used for determination of PCBs in real water with recoveries ranging from 75.8 to 115.6%. This study proposed a new type SPME coating of MTMS/SnO2 microspheres, which extended the potential of SnO2 in capturing and determining organic pollutants.

A Novel DLLME Method Involving a Solidifying Hydrophobic Deep Eutectic Solvent Using Hydrophilic Deep Eutectic Solvent as the Dispersant for the Determination of Polychlorinated Biphenyls in Water Samples.

This paper presents a novel dispersive liquid-liquid microextraction (DLLME) method that employs solidified hydrophobic deep eutectic solvent (DES) with hydrophilic DES acting as the dispersant. The aim is to enrich polychlorinated biphenyls (PCBs) from water samples for subsequent determination by gas chromatography-mass spectrometry. The effects of both the hydrophobic DES as the extractant and the hydrophilic DES as the dispersant were thoroughly investigated. Optimization of the key factors influencing extraction efficiency was performed, and the method was subsequently validated. Specifically, a hydrophobic DES called DES2, prepared by combining thymol and decanoic acid in a molar ratio of 3:2, was selected as the extraction solvent. Meanwhile, a hydrophilic DES named DES6, prepared from choline chloride and acetic acid in a molar ratio of 1:2, was chosen as a dispersant. Under the optimal extraction conditions, the developed method exhibited excellent linearity over the concentration range of 0.01-5.0 µg/L, low limits of detection ranging from 3.0 to 5.1 ng/L, relative standard deviations less than 4.1%, and enrichment factors between 182 and 204 for PCBs. Finally, the effectiveness of the developed method was successfully demonstrated through residue determination of PCBs in water samples.

GC-MS determination of polychlorinated biphenyls in water using extractive freezing-out of analytes

A method for determining polychlorinated biphenyls (PCBs) in water using the method of concentrating analytes through extractive freezing-out under the effect of a centrifugal forces (EFC) has been developed. A mathematical model for analyte extraction using a three-factor Box-Behnken design demonstrated that the content of acetonitrile in the extraction mixture is a significant factor, whereas the degree of PCBs chlorination and the concentration of analytes are insignificant parameters. Analysis of the surface area of the model allowed the determination of the optimal range of the acetonitrile concentration, which fell between 14 and 21%. A 15% content of acetonitrile in the extraction mixture provided maximum extraction efficiency for 7 different PCBs (>92%) across a wide range of analyte concentrations (1.0 – 5000 ng/liter). The relative standard deviations in the repeatability and reproducibility range from 4.2 to 6.8% and 5.3 to 8.1%, respectively, the accuracy of analyte determination being 10 – 15%. Petroleum hydrocarbons were not extracted into the acetonitrile extract and did not interfere with the determination of PCBs, which provided longer operation of the detector without any loss in the sensitivity. Co-extraction of polycyclic aromatic hydrocarbons and chlorinated pesticides did not affect the extraction of PCBs from water (95 – 100%) and did not touch on the metrological indicators of the determination procedure.

Concomitant determination of PAH, PCBs, and phthalates in indoor air and dust from residential houses in the Strasbourg region of France

Global attention is drawn to the significant issue of indoor pollution, given its direct negative impact on human health and wellness. Typically, individuals can nowadays spend 80% or more of their time in enclosed built locations where they can be prone to a multitude of harmful toxic chemicals distributed in particulate and gas phases. Therefore, a systematic efficient monitoring of such chemicals in indoor environments is urgently required to devise and implement various measures that allow their control. The objective of this study is to evaluate the concomitance occurrence of phthalates, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) within the indoor settings of residential homes in Strasbourg. It focused on both the indoor air and dust samples collected in nine residential homes in Strasbourg for a one-year sampling period, February 2016 - February 2017. For this, Radiello®, SiC© foams, and Tenax-TA® were successfully introduced and used as reliable passive samplers for the aforementioned matrices. Extractions were carried out using pressurized solvent extraction (PSE) followed by ATD-GC/MSMS analysis. The findings of the presented study revealed that 12 PAHs, 18 PCBs, and 7 phthalates were regularly perceived in the indoor environments of the houses under assessment. In gaseous samples, the average concentrations of the detected pollutant were approximately 3,919, 4.3, and 601.6 ng/sampler for PAHs, PCBs, and phthalates, respectively. As for dust samples, the average concentrations of the detected pollutant were approximately 3,438, 6.2, and 1,816.2 ng/g, respectively. The obtained results showed that PCBs exhibited the lowest concentration in both matrices. However, air samples were mostly contaminated by PAHs, while dust samples showed higher levels of phthalates. These results are correlated to the physico-chemical properties of these compounds and to their origin and source of emission. The findings of this study stress the importance of indoor pollution assessment so that the risks associated with it could be controlled.

A simultaneous dispersive liquid-liquid microextraction and GC-MS determination of PCBs and PAHs in nature waters

The subject of this study is polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) – super ecotoxicants and widely distributed organic pollutants in natural waters. Their danger lies in acute toxicity, cumulative action, and long-term effects on living organisms. The degree of water ecosystem pollution is assessed based on the levels of indicator compounds, with 16 PAHs and 7 PCBs. Assessing the levels of these super ecotoxicants when they are simultaneously present in natural waters is an urgent task of ecological monitoring in order to obtain reliable information about the pollution level of the water body. The aim of this study is to evaluate the possibility of dispersive liquid-liquid microextraction (DLLME) of PCBs and PAHs and GC-MS determination in natural waters in their simultaneous presence. To achieve the set goal, the peculiarities of simultaneous extraction and determination of PAHs and PCBs from natural waters were studied. The selected range of analyte concentrations was determined based on literature data on environmental monitoring and the maximum allowable concentrations (MAC) of the investigated components in natural waters. The similarity of the applied methods for extraction and detection of PAHs and PCBs allowed for the justification of the approach to selecting a universal sample preparation scheme for simultaneous extraction and GC-MS determination of both classes of analytes. The possibilities of modifications of DLLME extraction of PAHs and PCBs, differing in dispersion method and nature of the extractor, were studied in combination with chromatographic-mass spectrometric determination of the analytes. Simultaneous extraction of super-toxicants was achieved by applying DLLME with a binary dispersant – 500 μl acetone + 500 μl acetonitrile and 150 μl chloroform as the extractor. The chloroform extract after DLLME extraction of the analytes without re-dissolution was used for GC-MS determination of 16 PAHs and 7 PCBs on a specific 60 m long capillary column with a 5% polyarylene + 95% dimethylpolysiloxane stationary phase with gradual heating of the thermostat from 60 to 290°C. Using the selected ion monitoring (SIM) mode increased the reliability of component identification in matrices of natural waters. The possibility of mutual influence of ecotoxicants on their extraction in the presence of each other was studied. Dispersive liquid-liquid microextraction with a binary dispersant provided simultaneous extraction of analytes at a level of 80-97%. The proposed analysis scheme allowed for GC-MS determination of 16 PAHs and 7 PCBs in the presence of each other in natural waters over a wide range of concentrations (0.02-40 μg/L) with an accuracy of 7-18% (PAHs) and 11-18% (PCBs). The relative standard deviations of repeatability and reproducibility for PAHs were in the ranges of 3.1-6.5% and 4.3-7.7%, respectively, and for PCBs 2.8-5.3% and 3.4-6.0%.

Multivariate Optimization and Validation of a Modified QuEChERS Method for Determination of PAHs and PCBs in Grilled Meat by GC-MS.

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are recognized as carcinogens and mutagenic food contaminants that threaten public health. As for food safety aspects, control of these contaminants in processed and fatty food is necessary. In this study, eleven factors were screened by the Plackett-Burman design, and four variables were chosen to optimize with the central composite design (CCD) for the improvement of extraction and cleanup procedures of these food contaminants. The optimized variables include 5 g of sample, 2 mL mixture of 2/2/1 ethyl acetate/acetone/isooctane, 1.6 g of ammonium formate, 0.9 g of sodium chloride, and 0.25 g of sorbent Z-Sep+. A 5 min cleanup vortex time with the spike calibration curve strategy, analyzed by gas chromatography-mass spectrometry (GC-MS), led to the validated limits of quantification (LOQs) for 16 PAHs and 36 PCBs of 0.5-2 and 0.5-1 ng/g, respectively, and recoveries of 72-120%, with an average relative standard deviation (%RSD) of 17, for PAHs, and 80-120%, with an %RSD of 3, for PCBs. The method introduces excellent accuracy, precision, and efficiency, and minimizes matrix effects, and ensures a control procedure, adopted with international standards, for food authorities to determine the contaminants of interest in processed meat, and consequently, prevent food-borne disease to improve public health indices.

Study on simultaneous determination of OCPs, PCBs and PBDEs in fish sample: application for marine fish tissues collected from Hai Phong province

In this work, a GC-MS/MS-based analytical method using accelerated solvent extraction combined with multi-layer silica gel column for sample preparation was developed to simultaneously determine 20 organochlorine pesticides (OCPs), 28 polychlorinated biphenyls (PCBs) and 8 polybrominated diphenyl ethers (PBDEs) in fish tissue. The method detection limits (MDLs) were achieved in the range of 0.053 ng/g (α-chlordane) – 1.65 ng/g (δ-BHC), 0.07 ng/g (PCB-209) – 1.84 ng/g (PCB-28), 0.323 ng/g (BDE-209) – 0.796 ng/g (BDE-47) for OCPs, PCBs and PBDEs, respectively. Intra-day and inter-day repeatability of the analytical signal (peak area) were below 10.5% and 12.4%, correspondingly. The overall recovery was investigated by spiking experiments and ranged from 70.9 to 114%. The confirmation of this developed method was assessed by analysis of the standard reference material (SRM-1947) sample. The measured concentrations of target compounds were within the range of the certified values. This developed method was applied for analysis of OCPs, PCBs and PBDEs in five fish tissues collected randomly from local markets at Hai Phong province. Their concentrations (<MDL – 206 ng/g for OCPs, <MDL – 20.7 ng/g for PCBs and <MDL – 66.7 ng/g for PBDEs) were lower than the maximum residue levels permitted by European Union, Food and Agriculture Organization and World Health Organization.

Integrated Analysis of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls: A Comparison of the Effectiveness of Selected Methods on Dried Fruit Matrices

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are groups of chemical substances commonly found in the environment. Because of large differences in the concentrations of PAHs and PCBs in the materials tested, separate analytical methods specific to each group of compounds are usually used. The aim of this study was to compare methods for the determination of PAHs and PCBs that permit the simultaneous determination of these compounds from one solvent extract. The analysis of the content of 15 PCB congeners and 16 PAHs was conducted using dried fruits. The analyses were performed with gas chromatography coupled with mass spectrometry. PAHs and PCBs were determined separately in each fruit sample using specific extraction and cleanup procedures for the respective groups of compounds. Analyses were also performed with two methods that permitted the simultaneous analysis of PAHs and PCBs in one solvent extract. The integrated methods did not provide adequate extract cleanup of interfering substances; consequently, the results of determinations of PAHs and PCBs using these methods were significantly different from the values obtained with proven determination methods for PAHs and PCBs.

A Facile and Rapid Strategy for Quantifying PCBs in Cereals Based on Dispersive Solid-Phase Extraction and Gas Chromatography-Mass Spectrometry: A Reference for Safety Concerns in Sustainable Textiles.

Cereals and their derivative products such as starch and cyclodextrin are significant natural materials for sustainable textile processing (e.g., sizing, dispersing, etc.). However, the contamination of cereals with polychlorinated biphenyls (PCBs) is often neglected, which has led to increasing concerns due to the adverse effects on end users. Therefore, monitoring PCBs in cereals is of great importance in preventing health risks. However, high starch, protein, and fat contents make cereals a complicated matrix and can challenge the analysis of PCBs in cereals. This work describes a facile and rapid strategy for quantifying 18 PCBs in cereals that included corn, wheat, and rice through dispersive solid-phase extraction and gas chromatography with mass spectrometry. Importantly, this was the first time that carboxyl-modified, multi-walled carbon nanotubes were incorporated in the detection of PCBs in cereals. The influences of several parameters on the extraction and clean-up efficiency were investigated; these included the type and volume of extraction solvent, sonication time, and the type and dosage of the adsorbent. The matrix effects on quantification were also evaluated. This approach exhibited a better clean-up performance. All the analytes showed weak matrix effects, and thus a solvent standard plot could be prepared for their quantification. Spiking experiments in the selected matrices at three concentration levels from 0.5 to 10 μg/kg resulted in satisfactory recoveries that ranged from 79.2% to 110.5% with relative standard deviations (RSDs; n = 6) less than 10.3%. The limits of detection (LODs) and quantification (LOQs) ranged from 0.04 to 0.1 μg/kg and 0.1 to 0.4 μg/kg, respectively. The practical application of this method was investigated by analyzing actual cereal samples, which demonstrated that the proposed approach was a facile and efficient strategy for PCB determination and provided a reference for the safety evaluation of sustainable textiles. The method also could be generalized to other troublesome samples for testing of multiple PCBs.

Ant nest-like hierarchical porous imprinted resin-dispersive solid-phase extraction for selective extraction and determination of polychlorinated biphenyls in milk

Polychlorinated biphenyls (PCBs) are persistent toxic, organic chemicals that tend to accumulate in the food chain. This study reports the rapid and selective extraction and determination of PCBs (PCB81, 153, 105, 126, and 157) in milk samples by a dispersive solid-phase extraction (DSPE) coupled with gas chromatography-tandem mass spectrometry (GC–MS/MS). An ionic liquid-molecularly imprinted porous resin (IL-MIPPR) as a DSPE adsorbent was synthesized from m-aminophenol, formaldehyde, and 2,2′-benzidinedisulfonic acid as the monomer, crosslinker, and virtual template, respectively. The IL-MIPPR had a fast mass transfer (1.0 min) and good selectivity (imprinting factors of 1.8–3.0). The IL-MIPPR − DSPE − GC–MS/MS method exhibited good linearity (R2 ≥ 0.9995), the limit of detections (LODs) < 0.6 pg/g, and the recoveries ranged from 82.8 % to 106 % with relative standard deviations ≤ 6.6 %. This method is thus better than previously reported methods in terms of the LOD, the adsorbent dosage, and the extraction time.

Application of the QuEChERS method for the determination of pesticides, PAHs and PCBs in fish in Senegal

Pollution of water by persistent organic pollutants is well described; however, little is known about the accumulation of these pollutants by aquatic organisms. For this reason, a method based on QuEChERS extraction and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) was developed for the determination of pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in the muscles of five fish species from the bay of Soumbedioune (Dakar, Senegal). This method shows good recoveries of extraction (68.2-98.1% for pesticides, 83.87-98.10% for PAHs and 81.30-98.15% for PCBs), precision (% RSD ≤ 1%), sensitivity (LODs between 0.001 and 0.079 ng g−1), linearity (R2 ≥ 0.99) and repeatability and reproducibility, evaluated for three concentration levels (10 ng g−1, 200 ng g−1 and 500 ng g−1), ≤ 15% for the majority of pollutants under study except for alachlor, atrazine, acetochlor, dicofol, deltamethrin and dichlorvos where a RSD ≥ 20% was determined for the 10 ng g−1 concentration. Organic pollutants have been detected in fish from the Soumbedioune coast demonstrating the necessity of a regular survey of water and fish in order to protect the populations.

Selective enrichment and determination of polychlorinated biphenyls in milk by solid-phase microextraction using molecularly imprinted phenolic resin fiber coating

Owing to the severe toxicity and health hazard of polychlorinated biphenyls (PCBs) to humans, the efficient separation and determination of PCBs in dairy products is highly desirable and challenging. In this study, a new solid-phase microextraction (SPME) fiber was prepared by coating of a new molecularly imprinted phenolic resin (MIPR) in situ using a covalent grafting method. The MIPR coating, synthesized from 4-mercaptophenol and glutaraldehyde, provides rough surface with more adsorption sites; furthermore, the coating has a thickness of 1.0 μm, resulting in rapid equilibration. This new device has the advantages such as less coating peeling from the substrate and selective recognition enhancement of the coating. A highly selective and sensitive SPME-based method was developed using the developed fiber, coupled with GC-MS/MS, for the determination of polychlorinated biphenyls (PCBs) in milk samples. The developed MIPR-HS-SPME-GC-MS/MS method showed low detection limits (0.012–0.066 pg mL−1), good linearity (r ≥ 0.9991), satisfactory recovery (77.5–116.7%), efficient enhancement factors (362–2034 folds) and good reusability (50 cycles). Therefore, this is a simple and efficient strategy for monitoring trace PCBs in complex samples and is a potential alternative for improving the selectivity of SPME fibers by introducing MIPR into the fiber coating.

A simple and reliable method for separation of mineral oil/polychlorobiphenyl mixtures.

Polychlorinated biphenyls (PCBs) were broadly applied worldwide as electrical insulators in transformers and power capacitors, due to their high dielectric constant and non-flammability. They were often added to mineral oils (MOs) and used as dielectric fluids, which are nowadays classified as hazardous waste. Indeed, the Stockholm Convention aims to eliminate the use of equipment with PCB content greater than 0.005 wt-% (=50 ppm) by 2025. Accurate identification and quantification of small traces of PCBs contained in MO thus represent a great analytical challenge. To achieve this goal, a simple, cost-effective and fast chromatographic process was developed to separate PCBs from MO, allowing to obtain reliable data to determine the concentration of PCBs, reduced to 2-3 ppm. Experimental and analytical methods, such as thin layer chromatography, column chromatography as well as gas chromatography coupled with mass spectroscopy, were applied to acquire a high level of qualitative and quantitative determination of PCBs in transformer MOs.

Determination of 82 polychlorinated biphenyls in biological samples using accelerated solvent extraction-isotope dilution-high resolution gas chromatography-high resolution mass spectrometry

我国水产品中多氯联苯(PCBs)的检测方法,主要以6种指示性PCBs和12种二噁英类共平面PCBs为主,仅涵盖有限的PCBs。为更全面地获得生物体中PCBs的浓度水平,深入探讨PCBs在生物体内的代谢和富集特征,进而准确评价PCBs对人类的暴露水平及风险,以鱼和贝类作为生物样品代表,建立了加速溶剂提取-同位素稀释-高分辨气相色谱-高分辨质谱(ASE-ID-HRGC-HRMS)测定生物样品中82种PCBs的方法。比较了振荡提取和加速溶剂提取两种提取方式的回收率和重复性,最终采用正己烷-二氯甲烷(1∶1, v/v)对PCBs进行加速溶剂提取。考察了各流分淋洗液对PCBs的回收率,确定了样品提取液经8 g 44%酸性硅胶层析柱(内径15 mm), 90 mL正己烷洗脱的净化方式。样品提取液净化浓缩后进行HRGC-HRMS分析,色谱柱采用DB-5MS超低流失石英毛细管柱(60 m×0.25 mm×0.25 μm)。通过优化后的升温程序对化合物进行分离,以保留时间和两个特征离子精准定性,采用同位素内标法定量。结果表明,在0.1~200 μg/L范围内,平均相对响应因子(RRF)的相对标准偏差值(RSD, n=7)均≤20%,相关系数(r2)>0.99。生物样品中PCBs的方法检出限为0.02~3 pg/g;鱼类中PCBs平均加标回收率为71.3%~141%, RSD(n=7)为2.1%~14%;贝类中PCBs平均加标回收率为76.9%~143%, RSD为1.4%~11%。该方法灵敏、准确、可靠,可以更加全面具体地分析鱼和贝类等水产品受PCBs的污染情况,为国内外开展生物监测提供有效的技术支持,从而服务于相关生态环境管理及履行《斯德哥尔摩公约》。

An environmental friendly and stable analytical method for the determination of indicator polychlorinated biphenyls (PCBs) in solid and waste oil samples by gas chromatography-electron capture detector (GC-ECD)

This study presents the optimization and comprehensive verification studies of a stable analytical method for the determination of seven indicator polychlorinated biphenyls (PCBs) in solid and waste oil samples by using gas chromatography-electron capture detector (GC-ECD). In extraction method optimization, the maximum efficient and environmentally compatible extraction conditions were obtained at 30 mL hexane:acetone (3:1) use and 1.25 min solvent hold time. In validation studies, this method indicated an excellent linearity from 50 μg/L to 500 μg/L since the correlation coefficients higher than 0.9975 for all PCBs. The LOD values varied from 10.1 μg/L to 10.3 μg/L and the LOQ values ranged from 33.7 μg/L to 45.5 μg/L. The mean recoveries in soil, sewage sludge and waste oil varied as 85.6–97.7 %, 82.8–91.2 %, and 96.2–108.8 %, respectively. The intra-day precision (RSD, (%) in soil, sewage sludge and waste oil varied as 3.73–6.33 %, 3.72–8.91 %, and 1.37–5.44 %, respectively, whereas the inter-day precision (RSD, (%)) in sewage sludge changed from 2.35 to 9.74 %. In trueness, both results from CRMs (the recovery of PCBs varied 84.3 % to 114.4 %) and PTs (z-scores for indicator PCBs varied from (−0.5 to 1.65) demonstrate that this method possesses well enough and sufficient capability for the rapid, selective, and correct determination of indicator PCBs in soil and waste oil samples. There was no critical ME (recovery varied from 82.6 to 99.5 % in all matrices) and the RSD (%) values for each matrices was below 6 %. In the measurement uncertainty, the expanded uncertainties (µg/kg) of seven indicator PCBs changed from 3.50 to 4.38. The contributions from the sample preparation (45.19–53.83 %), the calibration curve (20.34–27.04 %) and the repeatability (11.80–18.02 %) were the major sources to the expanded uncertainty. In real samples, eleven sewage sludge, two soil, and twenty-seven waste oil samples had results above the LOQ for at least one indicator PCB.

Application of gas chromatography coupled to triple quadrupole mass spectrometry (GC-(APCI)MS/MS) in determination of PCBs (mono-to deca-) and PCDD/Fs in Chinese mitten crab food webs

Polychlorinated biphenyls (PCBs) and dibenzo-p-dioxins and furans (PCDD/Fs) are notorious persistent organic pollutants (POPs), which may bioaccumulate through food chain and play detrimental effects to organisms even at trace levels. Quantification of PCBs and PCDD/Fs in biotic samples is a great challenge. In the present study, gas chromatography coupled to triple quadrupole mass spectrometry with an atmospheric pressure chemical ionization source (GC-(APCI)MS/MS) was studied for the isotope-dilution analysis of PCBs (mono-to deca-) and PCDD/Fs in Chinese mitten crab food webs. High-resolution mass spectrometry (HRMS) was applied for comparison. Light PCBs are compared between the two instruments for the first time. After optimization of instrument parameters, the RSDs of relative response factors of calibration curves were between 3.4% and 15.5% for PCBs and 1.7%–7.9% for PCDD/Fs. The limits of detection were between 0.021 and 0.150 pg/mL for PCBs and 0.051–0.237 pg/mL for PCDD/Fs. PCB concentrations in crab food web samples detected by GC-(APCI)MS/MS were well correlated with those detected by HRGC/HRMS. A DiCB, 3,3′-dichlorobiphenyl (PCB11), was the dominant PCB congener in aquatic food webs. Other MoCB and DiCB congeners were also widely identified; hence, low-weight PCB congeners should arouse more concern in the future. GC-(APCI)MS/MS may become an alternative instrument satisfying the PCB and PCDD/F detection.

Determination of Persistent Organic Pollutants (POPs) in Propolis by Solid-Phase Extraction (SPE) and Gas Chromatography – Mass Spectrometry (GC-MS)

Bee products produced in environments with persistent organic pollutants (POPs) may be contaminated by these compounds. Propolis usually consists of beeswax, resins, water, inorganic and phenolic substances, and essential oils. Although there are some studies on the detection of POPs in honey and some bee products, these are quite limited. Because propolis is a botanical-based and highly complex matrix, and thus difficult to analyze, a reliable and selective method based on solid-phase extraction (SPE) combined with gas chromatography-mass spectrometry was developed for the determination of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the propolis. All analytes were extracted with acetonitrile and centrifuged for 10 min at 4000 rpm and 6 °C in a refrigerated centrifuge. The samples were filtered using a homemade SPE cartridge containing C18, primary-secondary amine, and magnesium sulfate. The residue collected with acetonitrile was subsequently analyzed by gas chromatography – mass spectrometry (GC-MS). The proposed method was validated according to the Eurachem guidelines and applied directly to the collected propolis samples. The results show that the method may be used successfully in residue monitoring laboratories for the determination of OCPs, PCBs and PBDEs in propolis.

Simultaneous determination of PCBs, OCPs and PAHs in mussel by ultrasound-assisted cloudy extraction and gas chromatography–tandem mass spectrometry

ABSTRACT A method for the simultaneous determination in mussel of 8 polychlorinated biphenyls (PCBs), 23 organochlorine pesticides (OCPs), and 35 polycyclic aromatic hydrocarbons (PAHs), including alkyl-PAHs, was optimised using ultrasound-assisted cloudy extraction and gas chromatography–tandem mass spectrometry (GC-MS/MS). Optimal selection of the extraction solvent and the dispersing solvent contributed to a high extraction yield and a clean extract. The ranges of the lower limits of detection of PCBs, OCPs and PAHs were 0.012–0.058, 0.01–0.29 and 0.01–0.5 μg kg−1, respectively. The feasibility of the proposed method was validated by analysing standard reference materials of mussel with satisfactory results. The precision achieved by this method was in the range of 0.677–2.69% (PCBs), 1.14–6.60% (OCPs) and 0.694–7.46% (PAHs), and its accuracy was in the range of 101–104% (PCBs), 99.6–106% (OCPs) and 101–110% (PAHs). The advantages of the method include the simultaneous measurement of 66 analytes and the simplicity, low cost and high sensitivity of the procedure. When the proposed method was used to analyse the target compounds in 11 mussel samples, the analytical results displayed a concentration range of 0.41–0.45 µg kg−1 for PCBs, 0.26–6.49 µg kg−1 for OCPs, and 3.48–30.69 µg kg−1 for PAHs.