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Method 0023A: A Healthier PBMS Alternative
Oral Presentation
Prepared by Y. Tondeur
SGS Analytical Perspectives, 2714 Exchange Drive, Wilmington, NC, 28405
Contact Information: yves.tondeur@sgs.com; 910-794-1613
ABSTRACT
Method 0023A is a good example of where the proper application of a PBMS (Performance-Based Measurement System) can lower costs while significantly increasing confidence in the data relative to standard methods for polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas samples. Method 0023A was introduced in the nineties in support of CAA/RCRA regulations for specific source categories. In particular, the EPA wanted to ensure that the target analytes present in the Filter/Particulate Matter/Probe Rinse (F/PM/PR) fractions were accounted for by requiring the latter to be analyzed as a separate sample. This choice leads to two analytical runs per sampling train.
The driving force behind this decision can be explained as follows. Under M0023A’s sister method (Method 23) there is a distinct possibility of underestimating the target analyte concentrations due to poor extraction efficiencies from the F/PM/PR fraction. This possibility arises from combining all of the fractions from a sampling train inside of the same Soxhlet extraction vessel and, typically, adding the labeled extraction standards to the resin only. Such a low bias is more likely when the particulate load is significant. Additionally, when the laboratory “folds” the F/PM/PR components on top of the resin/glasswool bed, with the former located above the Soxhlet apparatus’ solvent return elbow, poor extraction efficiencies are expected. Such a configuration prevents the F/PM/PR components from being submerged in solvent during the extraction cycles, increasing the likelihood of lower extraction efficiencies. Noteworthy is that such losses of analytes are undocumented, and are, therefore, uncorrected since the extraction standards are not introduced in this fraction. All of these issues can be addressed by the judicious selection and use of additional labeled PCDD/F standards, removing the need for doubling-up the analytical costs.
Oral Presentation
Prepared by Y. Tondeur
SGS Analytical Perspectives, 2714 Exchange Drive, Wilmington, NC, 28405
Contact Information: yves.tondeur@sgs.com; 910-794-1613
ABSTRACT
Method 0023A is a good example of where the proper application of a PBMS (Performance-Based Measurement System) can lower costs while significantly increasing confidence in the data relative to standard methods for polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas samples. Method 0023A was introduced in the nineties in support of CAA/RCRA regulations for specific source categories. In particular, the EPA wanted to ensure that the target analytes present in the Filter/Particulate Matter/Probe Rinse (F/PM/PR) fractions were accounted for by requiring the latter to be analyzed as a separate sample. This choice leads to two analytical runs per sampling train.
The driving force behind this decision can be explained as follows. Under M0023A’s sister method (Method 23) there is a distinct possibility of underestimating the target analyte concentrations due to poor extraction efficiencies from the F/PM/PR fraction. This possibility arises from combining all of the fractions from a sampling train inside of the same Soxhlet extraction vessel and, typically, adding the labeled extraction standards to the resin only. Such a low bias is more likely when the particulate load is significant. Additionally, when the laboratory “folds” the F/PM/PR components on top of the resin/glasswool bed, with the former located above the Soxhlet apparatus’ solvent return elbow, poor extraction efficiencies are expected. Such a configuration prevents the F/PM/PR components from being submerged in solvent during the extraction cycles, increasing the likelihood of lower extraction efficiencies. Noteworthy is that such losses of analytes are undocumented, and are, therefore, uncorrected since the extraction standards are not introduced in this fraction. All of these issues can be addressed by the judicious selection and use of additional labeled PCDD/F standards, removing the need for doubling-up the analytical costs.