Pretreatment techniques were compared.A GC-MS method has been developed for the determination of the residues of seven indicator polychlorinated biphenyls in plant oil.Samples were dissolved with 2 mL n-hexane,and pur...Pretreatment techniques were compared.A GC-MS method has been developed for the determination of the residues of seven indicator polychlorinated biphenyls in plant oil.Samples were dissolved with 2 mL n-hexane,and purified by acidification silica-gel column,mixed-metal silica-gel column,and alumina base,respectively.The eluent was concentrated and 1 mL n-hexane was added.And the analytes were determined by GC-MS using PCB 198 as an internal standard.The spiked recoveries were 89%-115%.The relative standard deviations were range of 4.87%-10.3%.The limits of detection were 0.2-1.0 μg/kg.展开更多
Labeled polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)were extracted by three different methods,i.e.,soxhlet extraction,hot extraction and accelerated solvent extraction(ASE).The PCDD/Fs were detected by...Labeled polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)were extracted by three different methods,i.e.,soxhlet extraction,hot extraction and accelerated solvent extraction(ASE).The PCDD/Fs were detected by high resolution gas chromatography-high resolution mass spectrometry.Comparisons of the three methods were carried out by recovery of PCDD/Fs,solvent consumption and extraction time.The results showed that all of the method could extract labeled PCDD/Fs efficiently.ASE was a time saving procedure with lowest consumption of solvents compared with the other two methods.展开更多
A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and a...A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and alumina clean up of PCDD/Fs in soil was achieved by accelerated solvent extractor.Then the multi-layer silica-gel column was used for further clean up.The whole method has been evaluated on certified reference soil and farm soil.Accuracy and precision of this method was tested with satisfactory results.展开更多
文摘Pretreatment techniques were compared.A GC-MS method has been developed for the determination of the residues of seven indicator polychlorinated biphenyls in plant oil.Samples were dissolved with 2 mL n-hexane,and purified by acidification silica-gel column,mixed-metal silica-gel column,and alumina base,respectively.The eluent was concentrated and 1 mL n-hexane was added.And the analytes were determined by GC-MS using PCB 198 as an internal standard.The spiked recoveries were 89%-115%.The relative standard deviations were range of 4.87%-10.3%.The limits of detection were 0.2-1.0 μg/kg.
文摘Labeled polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)were extracted by three different methods,i.e.,soxhlet extraction,hot extraction and accelerated solvent extraction(ASE).The PCDD/Fs were detected by high resolution gas chromatography-high resolution mass spectrometry.Comparisons of the three methods were carried out by recovery of PCDD/Fs,solvent consumption and extraction time.The results showed that all of the method could extract labeled PCDD/Fs efficiently.ASE was a time saving procedure with lowest consumption of solvents compared with the other two methods.
文摘A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and alumina clean up of PCDD/Fs in soil was achieved by accelerated solvent extractor.Then the multi-layer silica-gel column was used for further clean up.The whole method has been evaluated on certified reference soil and farm soil.Accuracy and precision of this method was tested with satisfactory results.
