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/...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 multilayer 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 9.0 ng/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 12.6 ng/g plasma. The validated method was applied to measure the concentrations of the total SCCPs(∑ SCCPs) in50 plasma samples from a general population. The measured plasma concentrations of ∑SCCPs ranged from <MDL to 203 ng/g wet weight(ww), with an average value of 32.0 ng/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.展开更多
Chlorinated paraffins（SCCPs） are widely used worldwide, and they can be released into the environment during their production, transport, usage and disposal, which pose potential risks for human health. In this work...Chlorinated paraffins（SCCPs） are widely used worldwide, and they can be released into the environment during their production, transport, usage and disposal, which pose potential risks for human health. In this work, an efficient, reliable and rapid pretreatment method based on matrix solid-phase dispersion（MSPD） was developed for the analysis of short-chain CPs（SCCPs） in human placenta by gas chromatograph-electron capture negative ion low-resolution mass spectrometry（GC-ECNI-LRMS） and gas chromatography–quadrupole time-of-flight mass spectrometry（GC–QTOF-HRMS）. The MSPD-relevant parameters including dispersing sorbent,sample-to-sorbent mass ratio, and elution solvent were optimized using the orthogonal test.Silica gel was found to be the optimal dispersing sorbent among the selected matrices. Under the optimal conditions, 44% acidic silica gel can be used as the co-sorbent to remove lipid and eluted by the mixture of hexane and dichloromethane（7：3, V/V）. The spiked recoveries of the optimized method were 77.4% and 91.4% for analyzing SCCPs in human placenta by GC-ECNI-LRMS and GC–QTOF-HRMS, and the corresponding relative standard deviations were10.2% and 5.6%, respectively. The method detection limit for the total SCCPs was 36.8 ng/g（dry weight, dw） and 19.2 ng/g（dw） as measured by GC-ECNI-LRMS and GC–QTOF-HRMS,respectively. The concentrations of SCCPs in four human placentas were in the range of展开更多
Pristine alpine regions are ideal regions for investigating the long-range atmospheric transport and cold trapping effects of short chain chlorinated paraffins(SCCPs).The concentrations and alpine condensation of SCCP...Pristine alpine regions are ideal regions for investigating the long-range atmospheric transport and cold trapping effects of short chain chlorinated paraffins(SCCPs).The concentrations and alpine condensation of SCCPs were investigated in lichen samples collected from the southeastern Tibetan Plateau.The concentrations of SCCPs ranged from 3098 to 6999 ng/g lipid weight(lw)and appeared to have an increasing trend with altitude.For congeners,C10 dominated among all the congener groups.The different environmental behavior for different congener groups was closely related to their octanol-air partition coefficient(Koa).C10 congeners showed an increasing trend with altitude,whereas C13 congeners were negatively correlated with altitude.Volumetric bioconcentration factors(BCF)of SCCPs reached 8.71 in lichens,which were higher than other semivolatile organic compounds(SVOCs)such as organochlorine pesticides(OCPs),polybrominated diphenyl ethers(PBDEs),polychlorinated biphenyls(PCBs),and hexabromocyclododecane(HBCD).These results suggested that SCCPs were prone to accumulate in the lichen from the air and provided evidence for the role of lichens as a suitable atmospheric indicator in the Tibetan Plateau.展开更多
Short-chain chlorinated paraffins（SCCPs） are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental beh...Short-chain chlorinated paraffins（SCCPs） are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental behaviors.A virtual molecule library of 42,720 C10-SCCP congeners covering the full structure spectrum was constructed.We explored the structural effects on the thermodynamic parameters and environmental degradability of C10-SCCPs through semi-empirical quantum chemical calculations.The thermodynamic properties were acquired using the AM1 method,and frontier molecular orbital analysis was carried out to obtain the EHOMO,ELUMO and ELUMO-EHOMO for degradability exploration at the same level.The influence of the chlorination degree（NCl on the relative stability and environmental degradation was elucidated.A novel structural descriptor,μ,was proposed to measure the dispersion of the chlorine atoms within a molecule.There were significant correlations between thermodynamic values and NCl,while the reported NCl-dependent pollution profile of C10-SCCPs in environmental samples was basically consistent with the predicted order of formation stability of C10-SCCP congeners.In addition,isomers with largeμ showed higher relative stability than those with small μ.This could be further verified by the relationship between μ and the reactivity of nucleophilic substitution and · OH attack respectively.The C10-SCCP congeners with less Cl substitution and lower dispersion degree are susceptible to environmental degradation via nucleophilic substitution and hydroxyl radical attack,while direct photolysis of C10-SCCP congeners cannot readily occur due to the large ELUMO-EHOMO values.The chlorination effect and the conclusions were further checked with appropriate density functional theory（DFT） calculations.展开更多
Chlorinated paraffins(CPs)are produced in large amounts and used worldwide.Dietary intake is the primary pathway for the exposure of pets to CPs,but limited information is available concerning the potential contaminat...Chlorinated paraffins(CPs)are produced in large amounts and used worldwide.Dietary intake is the primary pathway for the exposure of pets to CPs,but limited information is available concerning the potential contamination of pet food by CPs.In the present study,the concentrations and congener group profiles of short-chain CPs(SCCPs)and medium-chain CPs(MCCPs)were assessed in 35 imported commercial dry cat and dog foods collected in China,and the estimated daily intakes of SCCPs and MCCPs for cats and dogs through the consumption of such foods was calculated.The concentrations of SCCPs and MCCPs in the cat and dog foods were determined to be in the ranges of 108e45,300 ng/g(median:1340 ng/g)and 3.8e52,700 ng/g(median:11 ng/g),respectively.The predominant congener groups were C10Cl6 for SCCPs and C14Cl7-8 for MCCPs.The high levels of CPs found in certain pet foods suggest the potential for adverse health effects.展开更多
基金supported by the National Natural Science Foundation of China (No.21337002)the National Basic Research Program (973) of China (No.2015CB453100)
文摘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 multilayer 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 9.0 ng/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 12.6 ng/g plasma. The validated method was applied to measure the concentrations of the total SCCPs(∑ SCCPs) in50 plasma samples from a general population. The measured plasma concentrations of ∑SCCPs ranged from <MDL to 203 ng/g wet weight(ww), with an average value of 32.0 ng/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.
基金supported by the National Natural Science Foundation of China(Nos.21625702,21337002,21621064)the National Basic Research Program of China(No.2015CB453102)the Strategic Priority Research Program of the Chinese Academy of Science(No.XDB14010400)for the joint financial support
文摘Chlorinated paraffins（SCCPs） are widely used worldwide, and they can be released into the environment during their production, transport, usage and disposal, which pose potential risks for human health. In this work, an efficient, reliable and rapid pretreatment method based on matrix solid-phase dispersion（MSPD） was developed for the analysis of short-chain CPs（SCCPs） in human placenta by gas chromatograph-electron capture negative ion low-resolution mass spectrometry（GC-ECNI-LRMS） and gas chromatography–quadrupole time-of-flight mass spectrometry（GC–QTOF-HRMS）. The MSPD-relevant parameters including dispersing sorbent,sample-to-sorbent mass ratio, and elution solvent were optimized using the orthogonal test.Silica gel was found to be the optimal dispersing sorbent among the selected matrices. Under the optimal conditions, 44% acidic silica gel can be used as the co-sorbent to remove lipid and eluted by the mixture of hexane and dichloromethane（7：3, V/V）. The spiked recoveries of the optimized method were 77.4% and 91.4% for analyzing SCCPs in human placenta by GC-ECNI-LRMS and GC–QTOF-HRMS, and the corresponding relative standard deviations were10.2% and 5.6%, respectively. The method detection limit for the total SCCPs was 36.8 ng/g（dry weight, dw） and 19.2 ng/g（dw） as measured by GC-ECNI-LRMS and GC–QTOF-HRMS,respectively. The concentrations of SCCPs in four human placentas were in the range of
基金the Strategic Priority Research Program of the Chinese Academy of Sciencesthe Pan-Third Pole Environment Study for a Green Silk Road(Pan-TPE)(No.XDA2004050203)+3 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0605)the National Natural Science Foundation of China(No.21906096)the Youth Science Funds of Shandong Academy of Sciences(No.2019QN008)the Youth Innovation Promotion Association of CAS(No.2018052)。
文摘Pristine alpine regions are ideal regions for investigating the long-range atmospheric transport and cold trapping effects of short chain chlorinated paraffins(SCCPs).The concentrations and alpine condensation of SCCPs were investigated in lichen samples collected from the southeastern Tibetan Plateau.The concentrations of SCCPs ranged from 3098 to 6999 ng/g lipid weight(lw)and appeared to have an increasing trend with altitude.For congeners,C10 dominated among all the congener groups.The different environmental behavior for different congener groups was closely related to their octanol-air partition coefficient(Koa).C10 congeners showed an increasing trend with altitude,whereas C13 congeners were negatively correlated with altitude.Volumetric bioconcentration factors(BCF)of SCCPs reached 8.71 in lichens,which were higher than other semivolatile organic compounds(SVOCs)such as organochlorine pesticides(OCPs),polybrominated diphenyl ethers(PBDEs),polychlorinated biphenyls(PCBs),and hexabromocyclododecane(HBCD).These results suggested that SCCPs were prone to accumulate in the lichen from the air and provided evidence for the role of lichens as a suitable atmospheric indicator in the Tibetan Plateau.
基金jointly supported by the Chinese Academy of Sciences (Nos. KZCX2-YW-BR-25, XDB14030500 and YSW2013B01)the National High Technology Research and Development Program (863) of China (No. 2013AA065201)
文摘Short-chain chlorinated paraffins（SCCPs） are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental behaviors.A virtual molecule library of 42,720 C10-SCCP congeners covering the full structure spectrum was constructed.We explored the structural effects on the thermodynamic parameters and environmental degradability of C10-SCCPs through semi-empirical quantum chemical calculations.The thermodynamic properties were acquired using the AM1 method,and frontier molecular orbital analysis was carried out to obtain the EHOMO,ELUMO and ELUMO-EHOMO for degradability exploration at the same level.The influence of the chlorination degree（NCl on the relative stability and environmental degradation was elucidated.A novel structural descriptor,μ,was proposed to measure the dispersion of the chlorine atoms within a molecule.There were significant correlations between thermodynamic values and NCl,while the reported NCl-dependent pollution profile of C10-SCCPs in environmental samples was basically consistent with the predicted order of formation stability of C10-SCCP congeners.In addition,isomers with largeμ showed higher relative stability than those with small μ.This could be further verified by the relationship between μ and the reactivity of nucleophilic substitution and · OH attack respectively.The C10-SCCP congeners with less Cl substitution and lower dispersion degree are susceptible to environmental degradation via nucleophilic substitution and hydroxyl radical attack,while direct photolysis of C10-SCCP congeners cannot readily occur due to the large ELUMO-EHOMO values.The chlorination effect and the conclusions were further checked with appropriate density functional theory（DFT） calculations.
基金the National Natural Science Foundation of China(grant nos.21707164 and 3187131629)the Central Public Interest Scientific Institution Basal Research Fund of the Chinese Academy of Agricultural Sciences(grant no.Y2020PT38).
文摘Chlorinated paraffins(CPs)are produced in large amounts and used worldwide.Dietary intake is the primary pathway for the exposure of pets to CPs,but limited information is available concerning the potential contamination of pet food by CPs.In the present study,the concentrations and congener group profiles of short-chain CPs(SCCPs)and medium-chain CPs(MCCPs)were assessed in 35 imported commercial dry cat and dog foods collected in China,and the estimated daily intakes of SCCPs and MCCPs for cats and dogs through the consumption of such foods was calculated.The concentrations of SCCPs and MCCPs in the cat and dog foods were determined to be in the ranges of 108e45,300 ng/g(median:1340 ng/g)and 3.8e52,700 ng/g(median:11 ng/g),respectively.The predominant congener groups were C10Cl6 for SCCPs and C14Cl7-8 for MCCPs.The high levels of CPs found in certain pet foods suggest the potential for adverse health effects.
