Dioxin Task Force –Analytical Techniques二恶英–analtical技术小组.pptVIP

Laboratory requirements Dioxin Workshop, Leon Mexico  Richard Turle Analysis and Air Quality Division Environmental Science and Technology Centre Environment Canada Principle of Methods Add surrogates (labeled internal standards) or spike a blank sample Extract according to matrix type Clean-up (very critical step) Fractionate (very critical step) Concentrate to known volume Analyze by GC-ECD for screening or GC-HRMS Requirements for Dioxin Analysis Clean extraction lab HRGC-HRMS in EI mode Low Res NOT acceptable Labeled dioxin standards Highly trained staff A few CRMs available Reasons for Using HRMS Sensitivity Modern HRMS can detect 0.01- 0.02 fg/ul TCDD Resolution @ 10000 resolution can separate masses to 4 decimal places Necessary to eliminate co-eluting fragment ions from other compounds such as PCBs and chlorinated diphenyl ethers Eliminates the need for even more extreme cleanup procedures to remove matrix effects and interfering compounds Canadian Reference Methods PP dioxin reg under CEPA Performance based First use of LOQ 2,3,7,8 TCCD regulated Other PCDD/FS requested Internal QA Requirements for Dioxins in Environmental samples Compares Hi-Res and Low Res Applicable to all matrices Used in monitoring Cost of labs For dioxins, $500K for instrument, space needed for high-res GC-MS, clean extraction lab, wash-up lab etc ~ cost $0.5 to $1M – main cost due to HVAC needed. Also need UPS for continuous power supply How do you know analyses are good? Use spiked samples to ensure repeatability Use CRMs to establish accuracy Proficiency testing ensures comparability with peers Exchange calibration solutions Accreditation ensures good procedures; SOPS, quality system, management Accreditation in Canada Required by Environment Canada policy ISO 17025 CAEAL for environmental labs - Labs have published Scope of accreditation Labs must participate in PT if available Quality Assurance Summary – Method EPS RM/19 and PM/23 5)???? Two labeled analogs must be ad