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Analysis Methods for Lead in TSP and PM 10. ED-XRF. ICP-AES/OES. ICP-MS. Pb Analysis Methods, TSP (Pb-TSP). High-volume TSP sampling 8x10-inch glass fiber filter, 9-12 strips per filter for analysis Pb in TSP Analysis Methods
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Analysis Methods for Lead in TSP and PM10 ED-XRF ICP-AES/OES ICP-MS
Pb Analysis Methods, TSP (Pb-TSP) • High-volume TSP sampling • 8x10-inch glass fiber filter, 9-12 strips per filter for analysis • Pb in TSP Analysis Methods • Federal Reference Method (FRM) based on Atomic Absorption (AA) as described in 40 CFR part 50, Appendix G • EPA allowing GFAA method EQL-0380-044 as acceptable FRM • Either the AA or GFAA method can be used • Monitoring agencies must determine MDLs using per 40 CFR Part 53.33 and load alternate MDLs into AQS with observations • Federal equivalent Methods (FEMs) • New FEMs are needed to support lower concentration levels of 0.045 to 0.375 µg/m3 • Moving towards universally-applicable or “generic” FEMs • Encouraging monitoring agencies with existing Pb methods to submit new FEM applications (40 CFR Part 53.33)
Pb Analysis Methods, PM10 (Pb-PM10) • Low-volume PM10 sampling • 46.2-mm Teflon filter for analysis • Pb in PM10 Analysis Methods • FRM (40 CFR Part 50, Appendix Q) • Non-destructive Energy dispersive X-ray fluorescence (ED-XRF) method • FEMs (none yet approved) • FEM application and approval process same as for Pb-TSP • Moving towards universally-applicable or “generic” FEMs • EPA working on new FEMs for Pb-PM10 • Inductively-coupled plasma mass spectrometry (ICP-MS) • Inductively-coupled plasma atomic emission spectrometry/optical emission spectrometry (ICP-AES/OES) • Graphite furnace atomic absorption (GFAA) • May be available late 2009 or early 2010
Method Detection Limits (MDLs) • Method Detection Limit (MDL) estimates FEM requirements in Part 53.33 • MDL requirement is 5% of NAAQS or 0.0075 µg/m3 • References 40 CFR Part 136, Appendix B • Defined as the “minimum concentration of a substance that can be measured and reported with 99% confidence that the analyte concentration is greater than zero” • Determined from the standard deviation of repeated analyses of a series of blanks or low level standards • Minimum of seven blanks or standards used • Standard deviation multiplied by students’ t value • Reasonableness of MDL estimate is verified by analysis of standards at or near the MDL
Estimated MDLs for Pb in TSP and PM10 Methods MDL requirement is 5% of NAAQS or 0.0075 µg/m3
Process for FEM Testing • FEM test requirements for Pb-TSP and Pb-PM10 are specified in 40 CFR Part 53.33 • FEM test requires comparison of the candidate method to a reference method • Field samples in the 0.045 to 0.375 µg/m3 concentration range are used • Precision and bias requirements for the reference method using audit filter strips and repeated analyses of field samples • 5% Bias and 15% Precision • Precision and comparability requirements for the candidate method using field samples • 15% Precision and 20% Comparability • Applicant prepares application for candidate method and submits to EPA for review
FEM application process for methods used by Monitoring Organizations for NAAQS Reference Method GFAA EQL-044 or Flame AA FRL-001 Candidate FEM Pb Audit Strips (3 Strips) 1) Audit Samples (53.33 f) (3 Strips –triplicate analysis) 3)Precision & Comparability (53.33 k & l) 1 strip (triplicate analysis) x 5 filters (15 values) 5 filters 1 strip to candidate 1 to reference 2)Precision & Comparability (53.33 k & l) 1 strip (triplicate analysis) x 5 filters (15 values) 4) MDL from Blanks (53.33 m) (7 Strips) Reference/Candidate Method Samples (53.33 j) TSP Filters 0.045 – 0.375 ug/m3 “Generic” FEM application EPA/ORD Evaluation EPA/ORD Approval