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A Simplified Analytical Procedure for Simultaneous Determination of Alkylphenol Ethoxylates and Brominated Flame Retardants in Fish Tissue Samples from Vaal River,South Africa
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作者 Tlou B.Chokwe Jonathan O.Okonkwo +4 位作者 Linda L.Sibali Elmari Kruger Hein du Preez Reveck Hariram Esper J.Ncube 《American Journal of Analytical Chemistry》 2015年第5期422-428,共7页
In this study, the concentration of alkylphenol ethoxylates (APEs) and brominated flame retardants (BFRs) were determined in fish samples, Labeo umbratus and Carp, collected from the Vaal River in South Africa. Ultras... In this study, the concentration of alkylphenol ethoxylates (APEs) and brominated flame retardants (BFRs) were determined in fish samples, Labeo umbratus and Carp, collected from the Vaal River in South Africa. Ultrasonic-assisted extraction technique was used to extract the organic contaminants from fish samples, and the resulting extract was purified by sulphuric acid lipid removal followed by Strata X-cartridge SPE clean-up. The APEs and BFRs were derivatized using heptafluorobutyric anhydride before analysis with GC-MS. In both types of fish samples, lower oligomers of APEs were more abundant than the higher oligomers, while HBCD, BDE99 and PBB101 were the dominant BFRs. The concentrations of these pollutants ranged from 1.061 ng/g lipids (t-BP) in Labeo umbratus to 11.860 ng/g lipids (HBCD) in Carp. 展开更多
关键词 Alkylphenol Ethoxylates Brominated Flame Retardants Fish Sample Heptafluorobutyric Anhydride Derivatization vaal River South Africa
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Occurrence,distribution and ecological risk assessment of organophosphorus flame retardants and plasticizers in sediment samples along the Vaal River catchment,South Africa 被引量:6
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作者 Tlou B.Chokwe Jonathan O.Okonkwo 《Emerging Contaminants》 2019年第1期173-178,共6页
The occurrence,distribution and ecological risk assessment of twelve(12)organophosphorus flame retardants(OPFRs)were investigated in sediments from the Vaal River,South Africa.Six halogenated OPFRs[tris-(2-chloroethyl... The occurrence,distribution and ecological risk assessment of twelve(12)organophosphorus flame retardants(OPFRs)were investigated in sediments from the Vaal River,South Africa.Six halogenated OPFRs[tris-(2-chloroethyl)phosphate(TCEP),three isomers of tris-(chloropropyl)phosphate(TCiPPs),tris-(1,3-dichloro-2-propyl)phosphate(TDCiPP)and tris-(2,3 dibromopropyl)phosphate(TDBPP)]and six non-halogenated OPFRs[tris-(n-butyl)phosphate(TBP),tris-(phenyl)phosphate(TPhP),tris-(butyl ethoxy)phosphate(TBOEP),tris-(2-ethylhexyl)phosphate(TEHP),diphenyl-2-ethylhexyl phosphate(DPEHP)and tris-(m-cresyl)phosphate(m-TCP)]were detected in this study.The concentrations of twelve OPFRs in total(S12OPFRs)ranged from 68 to 278 ng g^-1 dry weight(dw)with the mean and median of 138 and 120 ng g^-1;respectively.The non-halogenated OPFRs showed more abundances than the halogenated OPFRs with TDBPP,TBP,and TBOEP the most abundant compounds.Generally,concentrations of OPFRs in more urbanized region were higher than those in less urbanized regions.When the concentrations of OPFRs and total organic carbon(TOC)were correlated,a moderate and significant correlation(p<0.05)was observed.Ecological risk were estimated and our results showed that m-TCP poses high risk(HQ>1)while TBOEP,TPhP,and TBP posed medium risk(0.1<HQ<1)with the remainder posing negligible risk(HQ<0.01).The data obtained in this study provides valuable information on the occurrence and risks of the investigated OPFRs within Vaal River. 展开更多
关键词 OPFRs CONCENTRATIONS Risk assessment SEDIMENTS vaal river
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Occurrence and distribution of tetrabromobisphenol A and its derivative in river sediments from Vaal River Catchment,South Africa 被引量:2
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作者 Tlou B.Chokwe Jonathan O.Okonkwo Mutshinyalo S.Nwamadi 《Emerging Contaminants》 2017年第3期121-126,共6页
Brominated flame retardants(BFRs)compounds have been widely added in a number of products to reduce their flammability.In the present study,the concentrations and distribution of tetrabromobisphenol A(TBBPA)and its de... Brominated flame retardants(BFRs)compounds have been widely added in a number of products to reduce their flammability.In the present study,the concentrations and distribution of tetrabromobisphenol A(TBBPA)and its derivatives,i.e.tribromophenol dibromopropyl ether(TBPDBPE),tetrabromobisphenol A bis-dibromopropyl ether(TBBPA BDBPE),tetrabromobisphenol A bis-allyl ether(TBBPA BAE)were investigated in sediment samples collected from the Vaal River catchment,South Africa.The results showed that all these pollutants were detected in sediments with TBBPA BAE being the most abundant contaminant.The TBBPA BAE concentrations ranged from 3.5 to 44.4 ng/g(mean 16 ng/g)while the concentration ranged from not detected(nd)to 2.4 ng/g(mean 0.6 ng/g),nd-21.0 ng/g(mean 6 ng/g)and nd-2.0 ng/g(mean 0.2 ng/g)for TBPDBPE,TBBPA and TBBPA BDBPE;respectively.Higher concentrations of these pollutants were found in sampling sites receiving effluents of wastewater treatment works(WWTWs)treating some industrial wastewater suggesting effluents might play an important role in the contamination of BFRs in the environment.Negative correlation between TBBPA and TBBPA BAE was observed implying different sources or environmental fates between these pollutants.Overall,the results showed a need for further studies to be undertaken in investigating the presence,fate and sources of alternative halogenated flame retardants in the environment. 展开更多
关键词 Brominated flame retardants Tetrabromobisphenol A derivatives CONCENTRATIONS SEDIMENTS vaal river
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潮湿细粒煤筛分过程中堵孔机理与解决办法 被引量:5
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作者 陈惜明 赵跃民 朱红 《江苏煤炭》 2000年第2期33-36,共4页
研究了普通振动筛上筛分外在水分为 7%~ 1 4%的潮湿细粒煤时筛孔堵塞机理 。
关键词 筛分 潮湿细粒物料 粘附模型 选煤 堵孔机理
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