National Air Quality Conference -- Addison, Texas – March 2, Analysis Methods for Lead in TSP and PM 10 ICP-MS ICP-AES/OES ED-XRF
National Air Quality Conference -- Addison, Texas – March 2, 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 as acceptable FRM Either the AA or GFAA method can be used Monitoring agencies must determine MDLs using per 40 CFR Part and load alternate MDLs into AQS with observations –Federal equivalent Methods (FEMs) New FEMs are needed to support lower concentration levels of to µg/m 3 Moving towards universally-applicable or “generic” FEMs Encouraging monitoring agencies with existing Pb methods to submit new FEM applications (40 CFR Part 53.33)
National Air Quality Conference -- Addison, Texas – March 2, Pb Analysis Methods, PM 10 (Pb-PM 10 ) Low-volume PM 10 sampling –46.2-mm Teflon filter for analysis Pb in PM 10 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-PM 10 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
National Air Quality Conference -- Addison, Texas – March 2, Method Detection Limits (MDLs) Method Detection Limit (MDL) estimates FEM requirements in Part –MDL requirement is 5% of NAAQS or µg/m 3 –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
National Air Quality Conference -- Addison, Texas – March 2, Estimated MDLs for Pb in TSP and PM 10 Methods MDL requirement is 5% of NAAQS or µg/m 3 Estimated MDL (µg/m 3 ) Sample Analysis Methods to a c Graphite Furnace Atomic Absorption (GFAA) b Energy-dispersive X-Ray Fluorescence (EDXRF) c Inductively Coupled Plasma Mass Spectrometry (ICP-MS) c Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES/OES) a Estimated MDL retrieved from AQS b 40 CFR Part 50, Appendix Q c Estimated MDLs reported in the Inorganic (IO) Compendium of Methods for the Determination of Inorganic Compounds in Ambient Air, EPA/625/R-96/01a, July 1999
National Air Quality Conference -- Addison, Texas – March 2, Process for FEM Testing FEM test requirements for Pb-TSP and Pb-PM 10 are specified in 40 CFR Part FEM test requires comparison of the candidate method to a reference method –Field samples in the to µg/m 3 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
National Air Quality Conference -- Addison, Texas – March 2, Reference/Candidate Method Samples (53.33 j) TSP Filters – ug/m3 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) Reference Method GFAA EQL-044 or Flame AA FRL-001 “Generic” FEM application Candidate FEM EPA/ORD Approval EPA/ORD Evaluation FEM application process for methods used by Monitoring Organizations for NAAQS Pb Audit Strips (3 Strips) 4) MDL from Blanks (53.33 m) (7 Strips) 2)Precision & Comparability (53.33 k & l) 1 strip (triplicate analysis) x 5 filters (15 values) 5 filters 1 strip to candidate 1 to reference