Short-chain Chlorinated Paraffins Research Articles

Elimination of short-chain chlorinated paraffins in diet after Chinese traditional cooking-a cooking case study

Short-chain chlorinated paraffins (SCCPs) were listed in the Stockholm Convention in 2017 yet are still used in large-tonnage in China. Diet is the main external exposure pathway of many persistent organic pollutants (POPs), but SCCP diet exposure has not been studied completely thus far. In this study, samples of 122 raw foods were collected from markets in Beijing, cooked with Chinese traditional cooking methods, and analyzed for SCCPs. Overall, SCCP levels in the raw food materials ranged from0.67 to 5100 ng g−1 wet weight (ww). SCCP elimination was found in six out of seven kinds in the cooking case study. Concentrations in the raw food used for cooking ranged from 3.6 to 52 ng g−1 ww, while the corresponding values in the cooked food ranged from 0.67 to 10.8 ng g−1 ww. The SCCP elimination rate ranged from 12% to 93%. The daily average intake of SCCPs for the general population through raw food and cooked food was assessed. The total daily SCCP intake via these foods was 403 and 145 ng kg−1 bw d−1, which suggests that different assessing approaches may result in different estimated SCCP diet exposure amounts.

Seasonal variations and inhalation risk assessment of short-chain chlorinated paraffins in PM2.5 of Jinan, China

Short-chain chlorinated paraffins (SCCPs) were added to the Stockholm Convention on Persistent Organic Pollutants (POPs) at the eighth meeting of the conference of the parties in 2017. As a consequence, increasing environmental attention and international regulation on SCCPs is expected in the future. Inhalation uptake of particulate matter (PM) was an important exposure pathway for POPs into the human body. In the present study, a total of eighty PM2.5 samples were collected in the four seasons of the year at an urban site (Shandong University, Jinan) in Shandong province to investigate the seasonal changes of SCCPs and their inhalation exposure risks to human health. The concentrations of SCCPs ranged from 9.80 to 105 ng m−3, with the mean value of 38.7 ng m−3. The highest concentrations of SCCPs were detected in winter, while the lowest concentrations were in summer. SCCPs concentrations were positively correlated with the mass concentrations of PM2.5 (r = 0.629, p < 0.01), and negatively correlated with the ambient temperature (r = −0.447, p < 0.01). The SCCPs congeners with 10 carbon atoms (C10 congeners) and 7 chlorine numbers (Cl7 congeners) were the predominant congeners, which contributed 35% and 37% of the total SCCPs contamination, respectively. The average inhalation exposure was estimated to be 1.75 × 10−4 mg kg−1 day−1 for adults, which is much lower than the “no observed adverse effect level” (NOAEL) of 100 mg kg−1 day−1 given by European risk assessment for SCCPs.

Determination of short-chain chlorinated paraffins using comprehensive two-dimensional gas chromatography coupled with low resolution mass spectrometry

Short-chain chlorinated paraffins (SCCPs), recently listed as Persistent Organic Pollutants (POPs) under the Stockholm Convention, are contained in commercial chlorinated paraffin (CP) products, which are used in industries such as metalworking fluids, sealants, and textiles. A novel method to determine SCCPs by comprehensive two-dimensional gas chromatography coupled with low resolution mass spectrometry was developed. Calibration curves of response factor versus chlorine content in two chlorine content ranges (R2 were 0.9544 and 0.9736, respectively) were used for quantification of SCCP total concentration. Moreover, relative concentrations of 24 congener groups were also theoretically calculated. Results showed that this method was able to detect SCCP concentration in commercial CP products and urban air samples. SCCP contribution varied largely among different CP products, which is highly determined by carbon chain distribution in paraffins. SCCP concentration in urban air ranged between 12.8–49.1 ng m−3 during nine-month sampling period. The highest SCCP concentration appeared in summer, and the lowest concentration occurred in winter. Gas phase was dominantly occupied by lighter congeners such as C10 group and Cl6 group, while heavier congeners such as C13 group and Cl7 and Cl8 groups contributed more in particle phase.

A clean-up method for determination of multi-classes of persistent organic pollutants in sediment and biota samples with an aliquot sample

In the present study, we developed a novel method to simultaneously detect eight classes of persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), polychlorinated naphthalenes (PCNs), organochlorine pesticides (OCPs), short-chain chlorinated paraffins (SCCPs) and Dechlorane Plus (DP), in sediment and fish tissue samples. The samples were extracted by accelerated solvent extraction (ASE) system, and the extracts were purified and fractionated into fraction1 and fraction2 with multi-layer silica gel column, followed by further fractionation using a basic alumina column (fraction1) and a Florisil column (fraction2), respectively. Finally, fractions were analyzed with different chromatographic columns and different detectors according to the properties of a chemical compound. The limit of detection for eight classes of POPs ranged from 1 to 30 pg/gdw in fish tissue samples, and from 1 to 33 pg/gdw in sediment samples, except for SCCPs (from 5.6 to 7.6 ng/g in fish tissue samples, and from 1.2 to 8.3 ng/gdw in sediment samples). The recoveries of eight classes of POPs spiked in fish tissue and sediment samples ranged from 43% to 120%, and from 45% to 115%, respectively. The relative standard deviation (RSD) was less than 25%. The accuracy of method was satisfactorily demonstrated by analysis of standard reference materials NIST SRM 1649b and WMF-01. In addition, the newly developed method was successfully applied for analysis of sediment and fish samples collected from the Baiyangdian Lake.

Headspace Solid-Phase Microextraction Coupled to Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry for the Determination of Short-Chain Chlorinated Paraffins in Water Samples.

Short-chain chlorinated paraffins (SCCPs) are a new type of persistent organic pollutants. In this work, a simple and effective method involving headspace solid-phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF-MS) was developed and optimized for the determination of trace SCCPs in water samples. The key parameters related to extraction and separation efficiency were systematically optimized. The SCCP congener groups were best resolved using an Rxi-5Sil MS (30 m × 0.25 mm × 0.25 µm) column followed by an Rxi-17Sil MS (1.0 m × 0.15 mm × 0.15 µm) column; the optimum extraction conditions were achieved with a 100 µm polydimethylsiloxane SPME fiber, when a 10 mL water sample added with 3.6 g sodium chloride was incubated for 15 min at 90°C and then extracted during 60 min at 90°C and desorption at 260°C for 2 min. The proposed method showed good linearity in the concentration range of 0.2–20.0 µg/L with the determination coefficient greater than 0.995. The detection and quantification limits ranged from 0.06 to 0.13 µg/L and 0.18 to 0.40 µg/L, respectively, which are sufficient to meet the regulatory detection limits as set by most environmental regulations. The accuracy and precision of the method was also good, where the recoveries ranged from 82.5 to 95.4%, and intra- and interday precision was within 7.2% and 14.5%, respectively. The optimized method has been applied to the determination of SCCPs in ten freshwater samples of three different types.

Chlorinated paraffins in the indoor and outdoor atmospheric particles from the Pearl River Delta: Characteristics, sources, and human exposure risks

Chlorinated paraffins (CPs) are ubiquitously present in the environment due to their abundant production and consumption. Information on CPs as part of indoor particles is very limited although a significant amount of time is spent in indoor environments. Seventy-two indoor and 66 outdoor TSP/PM10/PM2.5 samples (particulate matters with aerodynamic diameter <100, 10, and 2.5μm) from 24 homes of the Pearl River Delta (PRD), China, were analyzed for CPs. PM2.5 were found to be the dominant particles both indoors and outdoors. CPs were mainly distributed in PM2.5 that accounted for 89.1% and 93.0% of the total particles indoors and outdoors, respectively. The geometric mean (GM) concentrations of medium-chain CPs (MCCPs) exceeded those of short-chain CPs (SCCPs) (22.0 vs. 9.2ng/m3) in all particle samples. Both SCCPs and MCCPs in the indoor particles (GM: 13.4 and 30.9ng/m3) were approximately twice as high as in the outdoor environment (GM: 6.1 and 15.2ng/m3). C11 and C14 carbon chains as well as six and seven chlorine homologues were found to be predominant in all samples with average percentages of 43.0% and 55.4%, respectively. The estimated daily CP intakes via PM2.5 inhalation were 8.1–24.6 and 25.1–76.0ng/kg·bw/day for all age subgroups based on both mean and 95th percentile concentrations of CPs. However, the estimated daily uptakes decreased to 4.4–16.4 and 13.5–50.6ng/kg·bw/day, respectively, when the deposition fractions of PM2.5 in the human lung were considered. Indoor PM2.5 attributed to 93.8% exposure of CPs based on both total estimated daily intakes (EDIs) and estimated daily uptakes (EDUs), indicating that the indoor PM2.5 exposure was very important. Infants and toddlers suffered higher exposure risks of CPs compared to other subgroups, indicating higher potential health risks; however, based on the margin of the exposure analysis these risks could be ignored.

A hollow microporous organic network as a fiber coating for solid-phase microextraction of short-chain chlorinated hydrocarbons

A solid-phase microextraction (SPME) fiber coated with a hollow microporous organic network (H-MON) was fabricated for the analysis of short-chain chlorinated paraffins (SCCPs). The sorbent was prepared by reacting tetra(4-ethynylphenyl)methane and 1,4-diiodobenzene using bis-(triphenylphosphine) palladium(II) as the catalyst in the presence of silica sphere templates, which then were removed by hydrofluoric acid. The SCCPs were quantified by GC-MS working in the negative chemical ionization mode. The H-MON has a high specific surface (701m2·g-1) and microporosity (pore size <2nm). Extraction temperature, extraction time, and ionic strength of the sample solutions were optimized by using the Box-Behnken design. The head-space SPME exhibits better extraction performance than the direct immersion mode. Under optimal working conditions, the detection limit (3 times of the standard deviation) is 0.03ng·mL-1 in the water samples. Response is linear in the 0.05-10ng·mL-1 concentration range. Repeatability and reproducibility, expressed as the relative standard deviations, ranged from 4.6 to 11.0%. The method was successfully applied in the analysis of SCCPs in water, sediments, organisms, and atmospheric particulate matter samples. Graphical abstract Schematic of the fabrication of a hollow microporous organic network (H-MON) on stainless steel fibers for use inSPME. The method was applied to the determination ofshort-chain chlorinated paraffins in biological, environmental water and atmospheric particulate matter (PM2.5) samples.

Concentrations and congener group profiles of short- and medium-chain chlorinated paraffins in animal feed materials

Chlorinated paraffins (CPs) are ubiquitous environmental pollutants that are lipophilic and can accumulate in the food chain. Animal-derived products are predominant contributors to human CP exposure. CPs in animal feed might accumulate in domestic animals through dietary exposure, leading to potential contamination of animal-derived food products and human health risks. However, information on the presence of CPs in animal feed materials is scarce. In this study, 16 animal feed material samples were collected in China in 2016. Thirteen of the samples were of animal origin and three were of plant origin. The concentrations and carbon and chlorine congener group profiles of shortchain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in these animal feed materials were investigated. The concentrations of SCCPs were higher than those of MCCPs in all of the samples. The SCCP concentration range was 120 to 1700 ng/g (mean 640 ng/g), and the MCCP concentration range was 6.4 to 260 ng/g (mean 78 ng/g). Fish meal had the highest SCCP and MCCP concentrations. The lowest SCCP and MCCP concentrations were detected in peanut meal and whey powder, respectively. The concentrations of SCCPs and MCCPs varied among the types of animal feed materials. SCCP and MCCP concentrations also varied among samples of the same type of animal feed material. Relatively high concentrations of SCCPs and MCCPs were detected in feed materials of animal origin. The predominant congener groups in the animal feed materials were C10-11Cl6-7 for SCCPs and C14Cl7 for MCCPs. The carbon and chlorine congener group profiles of SCCPs indicated that SCCP contamination in the animal feed materials might arise from commercial CP mixtures.

Mass Fractions, Congener Group Patterns, and Placental Transfer of Short- and Medium-Chain Chlorinated Paraffins in Paired Maternal and Cord Serum.

Multiple studies have demonstrated the occurrences of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in environmental matrixes, but human internal exposure to them has been studied rarely. Mass fractions and congener group patterns of SCCPs and MCCPs in paired maternal and cord serum were studied for the first time to investigate the placental transport mechanism and prenatal exposure risks of CPs. Samples were collected in Beijing, China, and analyzed using two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. SCCP and MCCP mass fractions in maternal serum were 21.7-373 and 3.76-31.8 ng/g ww, respectively. They were 8.51-107 and 1.33-12.9 ng/g ww, respectively, in cord serum. Significant positive correlation between SCCP and MCCP levels in maternal serum was found ( p < 0.01), suggesting SCCPs and MCCPs may undergo similar accumulation, transfer, and transformation pathways. The predominant congener groups for SCCP and MCCP in maternal serum were C10-11Cl6-7 and C14Cl7-8. The homologue profiles of CPs in cord serum were similar but with varied contribution percentage compared with those in maternal serum. By calculating and comparing cord-maternal serum ratios for each individual congener group, passive diffusion was recognized to be the possible placental transport form. The relationships between CP and thyroid hormone concentrations (THs) indicated that exposure to CPs might affect circulating TSHs. C9-CPs were also detected, improving our understanding of CPs in human serum.

Partitioning of Chlorinated Paraffins (CPs) to Daphnia magna Overlaps between Restricted and in-Use Categories.

Chlorinated paraffins (CPs) are high-production volume industrial chemicals consisting of n-alkanes (with 10 to 30 carbon atoms in the chain) with chlorine content from 30 to 70% of weight. In Europe, the use of short chain chlorinated paraffins (SCCPs) has been restricted by the Stockholm Convention on POPs due to their PBT (persistent, bioaccumulative and toxic) properties. Medium (MCCPs) and long chain (LCCPs) chlorinated paraffins are used as substitution products. In this work we studied the partitioning behavior of five different CP technical mixtures from the established categories (2 SCCPs, 1 MCCP, 1 LCCP and 1 CP technical mixture covering all categories) using passive dosing, by determining the partitioning coefficient of CP technical mixtures between silicone and water ( Ksilicone-water) as well as between organic matter and water ( Koc-water). We show that both silicone-water and organic carbon-water partition coefficients overlap between different categories of CP technical mixtures. These results indicate that in-use MCCPs and LCCPs may be equally or more bioaccumulative than restricted SCCPs. For the tested mixtures, both chlorine content and carbon chain length showed a significant correlation with both Ksilicone-water and Koc-water.

Maternal-Child Exposures to Persistent Organic Pollutants in Dhaka, Bangladesh

Information about the human burdens of persistent organic pollutants (POPs) in low- and middle-income countries is limited. In particular, studies often include only a small subset of POPs. To address this data gap, we aimed to assess maternal-child exposures to POPs in Dhaka, Bangladesh. We quantified 16 organochlorine pesticides, 12 polychlorinated biphenyls, 21 brominated flame retardants, 18 per- and polyfluorinated alkyl substances, 2 polycyclic aromatic hydrocarbons, and short-chain chlorinated paraffins in 18 pooled samples of human cord blood from 90 mother–infant pairs living in Dhaka, Bangladesh (2014–2015). In all pooled samples, we detected high levels of p,p′-DDT (median 81.6 ng/g lipid) and its metabolites p,p′-DDE and p,p′-DDD (median 551 and 10.7 ng/g lipid, respectively), where the p,p′-DDE/p,p′-DDT ratio ranged from 2.9 to 9.8 indicating recent dichlorodiphenyltrichloroethane (DDT) exposure. We also detected acenaphthene, decabromodiphenyl ethane, o,p′-DDT, o,p′-DDE, hexachlorobenzene, β-hexachlorocyclohexane, hexabromobenzene, and perfluorooctanoic acid in a subset of samples. For the other 59 target compounds, concentrations were below the limits of detection, despite using ultra-trace analytical methodology. No trends were observed when stratifying the analyses of detected POP concentrations by maternal age, maternal body mass index, or large fish consumption. These findings highlight recent DDT exposure in Dhaka, but the overall POP burden was otherwise low in this sample of pregnant women/newborns. Future monitoring efforts should focus on newly detected POPs for which burdens may be increasing due to ongoing industrialization in Bangladesh.

Short-chain chlorinated paraffin (SCCP) pollution from a CP production plant in China: Dispersion, congener patterns and health risk assessment

China is the largest chlorinated paraffin (CP) producer in the world. Given that CP production is a major source of short-chain CP (SCCP) pollution in China, the effects of CP production on the environment inside and outside of CP production plants are worth revealing. The concentrations and specific congener group patterns of SCCPs in various environmental matrices, such as air, soil and dust, inside and outside of a chosen CP production plant surrounded by farmlands and villages were analyzed to explore SCCP pollution and transportation behaviors. SCCP concentrations in air (129–1442 ng/m3) and soil (28–554 μg/g) samples inside the CP production plant were dramatically higher than those in air (91–333 ng/m3) and soil (102–441 ng/g) samples outside the CP production plant. Based on the congener abundance patterns among these samples, lighter groups (C10-11 and Cl5-6) were dominant in atmospheric environment, with greater long-range transport potential, whereas heavier groups (C12-13 and Cl7-10) were inclined toward deposition. It was clear that substantial amounts of SCCPs were released from the CP production plant, which contaminated the environment inside and outside of the plant. The daily occupational SCCP exposure of employees in the production hall (21.8 μg/day-kg) exceeded the tolerable daily intake (TDI, 10 μg/day-kg) given by Canadian Environmental Protection Act, suggesting that production employees were confronted with high health risk from SCCP exposure; while daily SCCP exposure of employees in office areas (0.57 μg/day-kg) and residents near the CP plant (1.22–25.5 × 10−2 μg/day-kg) were significantly lower, representing low health risk.

Insight into the photocatalytic mineralization of short chain chlorinated paraffins boosted by polydopamine and Ag nanoparticles.

Short chain chlorinated paraffins (SCCPs) have attracted increasing attention recently due to their widespread occurrence and persistence in the environment, long-distance transport, and bioaccumulation and toxicity. For the sake of photocatalytic elimination of SCCPs, a kind of polydopamine (PDA) based photocatalyst, echinus-like Fe2O3@PDA-Ag hybrids have been synthesized via coating Fe2O3 with PDA by self-polymerization of dopamine and further loading silver nanoparticles by in situ reduction onto the surface of PDA shell. The photogenerated charges of Fe2O3@PDA-Ag hybrids exhibit long lifetime from transient photovoltage signal, which is of benefit to participate in various subsequent reaction processes before their recombination. Benefiting from the coating of PDA shell and the deposition of Ag nanoparticles, Fe2O3@PDA-Ag hybrids exhibit enhanced photocatalytic activity for the removel of SCCPs as investigated by the in situ Fourier transform infrared spectroscopy, 2.9 times as high as that of Fe2O3, due to the reactive OH radicals. The density functional theory simulation demonstrates the key mechanism of the formation of conjugate bond in the dechlorination process as well as the final product of HCl. The simulation indicates that there are no regularities for the H-abstraction but the dechlorination usually occurs in the adjacent Cl atoms next to the C with H-abstraction.

Solid-phase Extraction for Analysis of Short-Chain Chlorinated Paraffins in Water Samples

Abstract A method for analysis of short-chain chlorinated paraffins (SCCPs) in water based on solid-phase extraction (SPE) was established using electron capture negative chemical ionization mass spectrometry (GC-ENCI-MS). The SPE parameters, including the sorbent, eluent and elution volume were optimized. The Agilent Bond Elut-C18 was precleaned with 3 mL of hexane and 3 mL of methanol, and subsequently conditioned with 3 mL H2O prior to use. After the water samples were enriched by the cartridge, the sample was washed with 3 mL of 10% (V/V) methanol and eluted with 3 mL of hexane-dichloromethane (1:1, V/V) solution. The results indicated that the limits of detection (LOD) for SCCPs were 18 ng L−1, while the corresponding limits of quantitation (LOQ) were 60 ng L−1. The spiked recovery range was 90%–135%, with a relative standard deviation of less than 10%. Finally, 20 surficial water samples around Beijing were collected and SCCPs contents were analyzed using the proposed method. The SCCPs concentrations ranged from less than LOD to 682 ng L−1 with a mean concentration of 216 ng L−1.

Air-Seawater Gas Exchange and Dry Deposition of Chlorinated Paraffins in a Typical Inner Sea (Liaodong Bay), North China.

As a group of new persistent organic pollutants, short-chain chlorinated paraffins (SCCPs) and medium-chain CP (MCCPs) have attracted extensive worldwide interest in recent years. However, the data regarding to the environmental behavior, especially in atmospheric transfer and air-seawater exchange, are still sparse. In this study, seasonal marine boundary layer air and seawater samples were collected from Chinese Bohai sea and a fugacity model was built to evaluate the air-seawater diffusion and deposition flux of CPs. Generally, the total CP levels in atmosphere and seawater samples in summer were higher than those in spring, and CPs existed mostly in the gaseous phase in air and the dissolved phase in seawater. For SCCPs, C10 and C11 components were the most abundant homologue groups. For MCCPs, the C14 homologue dominated in the particle phase of atmosphere and particulate phase of seawater. The logarithmic fugacity ratios (log fa/ fw) of higher chlorinated congeners (Cl8 to Cl10: 0.71 to 1.32 in May and 1.38 to 2.29 in August) indicated that net deposition was the predominant process, whereas lower chlorinated congeners, especially Cl5 homologue groups in August, showed a trend of net volitization (log fa/ fw < -0.5). The results of diffusion and dry deposition fluxes indicated that air-seawater gas exchange of CPs was significantly higher than dry deposition in the sampling areas.

The thermal transformation mechanism of chlorinated paraffins: An experimental and density functional theory study.

The increasing production and usage of chlorinated paraffins (CPs) correspondently increase the amount of CPs that experience thermal processes. Our previous study revealed that a significant amount of medium-chain chlorinated paraffins (MCCPs), short-chain chlorinated paraffins (SCCPs) as well as aromatic and chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) were formed synergistically during the thermal decomposition of CP-52 (a class of CP products). However, the transformation mechanisms of CP-52 to these compounds are still not very clear. This article presents a mechanistic analysis on the decomposition of CP-52 experimentally and theoretically. It was found that CP-52 initially undergoes dehydrochlorination and carbon chain cleavage and it transformed into chlorinated and unsaturated hydrocarbons. Cyclization and aromatization were the most accessible pathways at low temperatures (200-400°C), both of which produce mostly aromatic hydrocarbons. As the temperature exceeds 400°C, the hydrocarbons could decompose into small molecules, and the subsequent radical-induced reactions become the predominant pathways, leading to the formation of Cl-PAHs. The decomposition of CP-52 was investigated by using density functional theory and calculations demonstrating the feasibility and rationality of PCB and PCN formation from chlorobenzene. The results improve the understanding of the transformation processes from CP-52 to SCCPs and Cl-PAHs as well as provide data for reducing their emissions during thermal-related processes.

Ecotoxicity assessment of short- and medium-chain chlorinated paraffins used in polyvinyl-chloride products for construction industry

Short chain chlorinated paraffins (SCCPs) have been commonly used as plasticizers and flame retardants in polyvinyl-chloride (PVC) products for the construction industry. During the last few years the production of SCCPs has been banned or reduced in Europe, Japan, USA, and Canada due to their toxic and bioaccumulative effects but they have been still produced and used under less controlled conditions worldwide. Middle chain chlorinated paraffins (MCCPs) were suggested as a suitable alternative to SCCPs for PVC production instead. In this paper, the ecotoxicity of SCCPs and MCCPs is studied using the methods of potentially affected fraction of species (PAF) and the most sensitive species (MSS). Characterization factors (CFs) are estimated for SCCPs by the PAF method (for MCCPs suitable ecotoxicological indexes are not available) and for MCCPs by the MSS method (for SCCPs PEC values are negligible). Results of the present study indicate that from an ecotoxicological point of view, MCCPs may present similar ecological risks as SCCPs. Therefore, it is recommended both SCCPs and MCCPs not to be used worldwide in PVC products for the construction industry. The most suitable alternative for SCCPs seems to be inorganic compounds but their environmental impacts have not been sufficiently excluded yet.

Determination of Chlorinated Paraffins by Bromide-Anion Attachment Atmospheric-Pressure Chemical Ionization Mass Spectrometry

A novel method for the quantitative determination of chlorinated paraffins (CPs) was developed using bromide-anion attachment atmospheric-pressure chemical ionization mass spectrometry (APCI-MS). Bromoform was used to enhance ionization of CPs. Near exclusive formation of stable bromide adduct ions ([M + Br]−) enabled accurate detection of individual CP congener groups (CnClm) with only a moderate-resolution quadrupole time-of-flight mass spectrometer. Furthermore, the method was free from interference commonly observed with chloride-anion attachment methods (e.g., decomposition ions [M + Cl – HCl]−) that require deconvolution. Together with a CnClm-response-factor algorithm for quantifying short-chain CPs and a CnClm-pattern-reconstruction algorithm for quantifying medium- and long-chain CPs, method applicability was demonstrated on biota and sediment samples. These data were generated significantly faster and with improved selectivity and sensitivity versus those of conventional measurements by chloride...

Validation of a HRGC–ECNI/LRMS method to monitor short-chain chlorinated paraffins in human plasma

Short-chain chlorinated paraffins (SCCPs) are produced in high volume and have the high potential to pose a threat to human health. However, little information is available for SCCP contamination in human blood/plasma/serum, mainly due to the difficulty of sample preparation and quantitative analysis. A method using high resolution gas chromatography coupled with electron capture negative ionization low resolution mass spectrometry (HRGC–ECNI/LRMS) was developed and validated to measure SCCPs in human plasma. The pretreatment process included protein denaturation and lipid elimination, liquid–liquid extraction with a mixture of n-hexane/dichloromethane (1:1, V/V), and cleanup on a multi-layer silica column. The blank controls, including procedural blank, vacuum blood collection tube blank, and instrumental blank, were the most pivotal points for the reliable analysis of SCCPs. The average value of procedural blanks was 9.0ng/g; and the method detection limit (MDL), calculated as the sum of the average procedural blank value and 3 times of the standard deviation of the procedural blanks, was 12.6ng/g plasma. The validated method was applied to measure the concentrations of the total SCCPs (∑SCCPs) in 50 plasma samples from a general population. The measured plasma concentrations of ∑SCCPs ranged from <MDL to 203ng/g wet weight (ww), with an average value of 32.0ng/g ww. The relative abundance profiles of SCCPs in plasma samples were dominated by C10- and C11-CP congener groups centered on Cl6–7. The developed method can be used for the comprehensive and large-scale investigation of SCCP levels in human plasma.

Life cycle of PCBs and contamination of the environment and of food products from animal origin

This report gives a summary of the historic use, former management and current release of polychlorinated biphenyls (PCBs) in Germany and assesses the impact of the life cycle of PCBs on the contamination of the environment and of food products of animal origin. In Germany 60,000t of PCBs were used in transformers, capacitors or as hydraulic oils. The use of PCB oils in these "closed applications", has been banned in Germany in 2000. Thirty to 50% of these PCBs were not appropriately managed. In West Germany, 24,000t of PCBs were used in open applications, mainly as additive (plasticiser, flame retardant) in sealants and paints in buildings and other construction. The continued use in open applications has not been banned, and in 2013, an estimated more than 12,000t of PCBs were still present in buildings and other constructions. These open PCB applications continuously emit PCBs into the environment with an estimated release of 7-12t per year. This amount is in agreement with deposition measurements (estimated to 18t) and emission estimates for Switzerland. The atmospheric PCB releases still have an relevant impact on vegetation and livestock feed. In addition, PCBs in open applications on farms are still a sources of contamination for farmed animals. Furthermore, the historic production, use, recycling and disposal of PCBs have contaminated soils along the lifecycle. This legacy of contaminated soils and contaminated feed, individually or collectively, can lead to exceedance of maximum levels in food products from animals. In beef and chicken, soil levels of 5ng PCB-TEQ/kg and for chicken with high soil exposure even 2ng PCB-TEQ/kg can lead to exceedance of EU limits in meat and eggs. Areas at and around industries having produced or used or managed PCBs, or facilities and areas where PCBs were disposed need to be assessed in respect to potential contamination of food-producing animals. For a large share of impacted land, management measures applicable on farm level might be sufficient to continue with food production. Open PCB applications need to be inventoried and better managed. Other persistent and toxic chemicals used as alternatives to PCBs, e.g. short chain chlorinated paraffins (SCCPs), should be assessed in the life cycle for exposure of food-producing animals and humans.