CHESTER LabNet

12242 SW Garden Place  Tigard, OR 97223-8246  USA 

Telephone 503-624-2183  Fax 503-624-2653  www.chesterlab.net 

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Gravimetry (PM10) 

Gravimetry is accomplished following the PM2.5 protocols at 40 CFR 50, Appendix L and 

Section 2.12 of the EPA Quality Assurance Handbook for Air Pollution Measurement Systems. 

The PM10 method, 40 CFR 50 appendix J, only refers to high volume samples, so the laboratory 

uses the procedures and more stringent QC in appendix L. Chester LabNet operates two 

microbalances capable of measuring mass to one microgram. The balances are under computer 

control, and all weighing operations follow a strict QC program. All filters are allowed to 

stabilize for two to three weeks, inspected and equilibrated for at least 24 hours in the controlled 

temperature and humidity weighroom before weighing. Briefly, the filters are tare weighed in 

batches of ten or less filters with calibration and zero checks before and after every batch. All 

tare-weighed filters are equilibrated for a minimum of another 20 hours, and 10% are reweighed 

to demonstrate constant weight. The 10% reweight procedure is also followed for the gross 

weighing of exposed filters returned from the field. Gravimetry data are batch imported from the 

balance computer directly into the LIMS. Filters are loaded into cassettes in a laminar flow hood 

to prevent contamination. 

 Balance QC statistics and calibration and gravimetry QC checks are as follows: 

QC Element Frequency QC Criterion 

balance resolution -- 1 μg 

balance precision -- ± 1 μg 

balance calibration Daily -- 

balance zero 10% -- 

calibration verification 10% ± 3 μg 

24-hour tare reweigh 10% ± 10 μg 

24-hour gross reweigh 10% ± 10 μg 

Currently, all filters for the project are weighed on a Sartorius model ME5 microbalance. That 

balance is calibrated daily using the internal calibration. The calibration is checked before and 

after each set of ten filters or less using a 200 mg weight, serial number 2008014, and a 100 mg 

weight, serial number 5316. The calibration is also checked monthly with a separate set of 200 

mg and 100 mg weights, serial number 21386. The calibration certificates for the balances and 

the weights are attached. 
XRF (metals including Pb) 

At Chester LabNet, XRF is accomplished following U.S. EPA Method IO-3.3 in Compendium 

of Methods for the determination of Inorganic Compounds in Ambient Air (EPA 625/R-96/010a) 

as modified for use with a Kevex Model 770 spectrometer. Calibration is via commercial, 

single-element, thin-film, vapor-deposited standards (from MicroMatter, Inc.) and organometallic acetate film standards containing two or more non-interfering elements (from U.S. 

EPA). Because of the extreme stability of XRF instruments, initial calibration may hold for 

many months. Calibration verification is accomplished by the analysis of NIST thin film 

standards SRM 1832 and SRM 1833 for eleven representative elements. The certificates of 

analysis for the NIST SRMs are attached. Precision is checked by the analysis of six elements 

on a quality control standard filter and by analysis of a sample replicate. Several elements, 

including S, K, Ca, Fe, Cu, and Zn are measured under more than one of the several excitation 

conditions normally used for each sample filter. 

The QC elements for the analysis of elements by x-ray fluorescence, their frequency of 

application and control limits, and corrective actions are as follows: 

QC Element Frequency Control Limits Corrective Action 

calibration as needed -- -- 

calibration verification weekly within NIST 

uncertainties 

recalibrate 

instrument precision once per batch of <

15 

90 – 110% recovery batch reanalysis 

Inter-excitation 

condition check 

every sample within analysis 

uncertainty 

determine cause - 

remedy 

sample replicate 

precision 

10% within analysis 

uncertainty 

determine cause - 

remedy 

Also, Chester LabNet (operating then as NEA, Inc.) developed an equivalent method for the 

determination of lead in ambient air particulates by XRF in 1989. This was before IO-3.3 was 

published. The acceptance letter for the equivalent method is attached, as well. 
Gravimetric 

Calibration 

Certificates 















X-Ray Fluorescence 

NIST Certificates 

of Analysis












X-Ray Fluorescence 

Equivalent Method 

Documentation 
List of Designated Reference and Equivalent Methods, April 8, 2004 Page 20

42-006 Pressure transducer (Model 42 only)

42-007 Ozone particulate filter

42-008 RS-232/485 interface

42-009 Permeation dryer

[Federal Register: Vol. 54, page 50820, 12/11/89]

Thermo Electron/Thermo Environmental Instruments Model 14 BIE AutomatedReference Method: RFNA-0179-035

"Thermo Electron or Thermo Environmental Instruments, Inc. Model 14 B/E Chemiluminescent NOINOiNOx Analyzer," operated on

the 0-0.5 ppm range, with or without any ofthe following options:

14-001 Teflon Particulate Filter 14-003 Long-Time Signal Integrator 14-005 Sample Flowmeter

14-002 Voltage Divider Card 14-004 Indicating Temperature Controller 14-006 Air Filter

[Federal Register: Vol. 44, page 7805, 02/07/79 and Vol.44, page 54545, 09/20/79]

Thermo Electron/Thermo Environmental Instruments Model 14 DIE AutomatedReference Method: RFNA-0279-037

"Thermo Electron or Thermo Environmental Instruments, Inc. Model 14 D/E ChemiluminescentNOIN021N0x Analyzer," operated on

the 0-0.5 ppm range, with or without any ofthe following options: 14-001 Teflon Particulate Filter; 14-002 Voltage Divider Card.

[Federal Register: Vol. 44, page 10429,02/20/79]

Thermo Environmental Instruments Models 42, 42C NO/N0z/NOx Analyzer AutomatedReference Method: RFNA-1289-074

"Thermo Environmental Instruments Inc. Model 42 or Model 42C NO-N02-NOx Analyzer," operated on any measurement range

between 0-50 ppb1 and 0-1000 ppb, with any time average setting from 10 to 300 seconds, with temperature and/or pressure

compensation on or off, operated at temperatures between 15 DC and 35 DC, with or without an exhaust ozone scrubber or any ofthe

following options: 2

42-002 Rack mounts

42-003 Internal Zero/span and sample valves with remote activation

42-004 Sample/ozone flow meters (Model 42 only)

42-005 4-20 rnA current output

Reference Method for Lead Manual Reference Method: 40 CFR Part 50, Appendix G

Reference Method for the Determination ofLead in Suspended Particulate Matter Collected from Ambient Air.

[Federal Register: Vol. 43, page 46258, 10/05/78]

Energy-Dispersive X-Ray Fluorescence Spectrometry (TNRCC) Manual Equivalent Method: EQL-0783-058

"Determination ofLead Concentration in Ambient Particulate Matter by Energy-Dispersive X-Ray Fluorescence Spectrometry (Texas

Natural Resource Conservation Commission)" Texas Natural Resource Conservation Commission, P.O. Box 13087, Austin, TX 78711-

3087. [Federal Register: Vol. 48, page 29742,06/28/83]

Energy-Dispersive X-Ray Fluorescence Spectrometry (NEA, Inc.) Manual Equivalent Method: EQL-0589-072

"Determination ofLead Concentration in Ambient Particulate Matter by Energy-Dispersive X-Ray Fluorescence Spectrometry (NEA,

Inc.)" Nuclear Environmental Analysis, Inc., Suite 260, 10950 SW 5th Street, Beaverton, OR 97005.

[Federal Register: Vol. 54, page 20193,05/10/89]

Flame Atomic Absorption Spectrometry Manual Equivalent Method: EQL-0380-043

"Determination ofLead Concentration in Ambient Particulate Matter by Flame Atomic Absorption Spectrometry Following Ultrasonic

Extraction with Heated HN03-HCl" Federal Register: Vol. 45, page 14648,03/06/80]

Flameless Atomic Absorption Spectrometry (EPA/RTP, N.C.) Manual Equivalent Method: EQL-0380-044

"Determination ofLead Concentration in Ambient Particulate Matter by Flameless Atomic Absorption Spectrometry (EPA/RTP, N.C.)"

[Federal Register: Vol. 45, page 14648,03/06/80]

Flameless (Graphite Furnace) Atomic Absorption (Houston, Texas) Manual Equivalent Method: EQL-0895-107

"Determination of Lead Concentration in Ambient Particulate Matter by Flameless (Graphite Furnace) Atomic Absorption (City of

Houston, Texas)." Health and Human Services Department, Environmental Chemistry Service, 1115 S. Braeswood, Houston, TX

77030. [Federal Register: Vol. 60, page 39383, 08/02/95]

Flameless Atomic Absorption Spectrometry (Omaha) Manual Equivalent Method: EQL-0785-059

"Determination ofLead Concentration in Ambient Particulate Matter by Flameless Atomic Absorption Spectrometry (Omaha-Douglas

County Health Department)" Omaha-Douglas County Health Department, 1819 Farnam Street, Omaha, NE 68183.

[Federal Register: Vol. 50, page 37909, 09/18/85]
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

ATMOSPHERIC RESEARCH AND EXPOSURE ASSESSMENT LABORATORY

RESEARCH TRIANGLE PARK

NORTH CAROLINA 27711

May 10, 1989

Ms. lisa M. Caldwell

NEA, Inc.

Su ite 260

10950 S. W. 5th Street

Beaverton, Oregon 97005

Re: Request for Equivalent Method Determination

Dear Ms. Caldwell:

Pursuant to Section 53.8 of Title 40, Chapter I, Part 53 of the Code of

Federal Regulations (40 CFR 53.8), you are hereby notified that your X-ray Fluorescence Spectrometry method for the determination of lead concentration in

suspended particulate matter collected from ambient air has been designated as

an equivalent method by the Administrator of the Environmental Protection Agency in accordance with Part 53. The method is identified as:

EQl-0589-072, "Oetermination of lead Concentration in Ambient

Particulate Matter by Energy Oispersive X-ray Fluorescence

Spectrometry (NEA, Inc.l."

Note the "designated method identification number" which has been assigned

to the method. This number identifies the method as a designated reference or

equivalent method. Any.significant changes to the method must be approved by EPA, 'either as a modification under Section 2.8 of 40 CFR Part 58, Appendix C

(Modifications of Methods by Users) or under 40 CFR Part 53 as a modified or

new method.

As provided in 40 CFR 53.8, a notice of this designation has been submitted

for publication in the Federal Register. Until that notice is pUblished, .this

letter will constitute proof of the designation. This newly designated method

will also be added to the current list of designated reference and equivalent

methods maintained by this office. The updated list will be sent to the EPA

Regional Offices and will be available to anyone upon request, either through the Regional Offices or through this office.

As a designated equiva lent method, this method is acceptab le~ {or us by

NEA, Inc. for purposes of 40 CFR Part 58, Ambient Air Quality SurVeillance.

For such use, the method must be used in strict accordance with the operational procedures or instruct ion manua 1 associ ated with the method and submitted as

part of your request for an equivalent method determination.
Ms. Lisa M. Caldwell

May 10, 1989

It is anticipated that requests for technical information and copies of

the method description will be directed to both NEA, Inc. and EPA. We plan to

distribute copies of the method description upon request but prefer that

technical questions concerning the method be directed to NEA, Inc.

If you should have any questions concerning this action, please contact me

by letter or by telephone (919) 541-2665.

Sincerely yours,

~~A~ef Ambient Methods Standardization Branch

Quality Assurance Division (MD-77).

cc: Barry Towns, ESD/USEPA~ Region X

Jon Schweiss, ESD/USEPA, Region X

Stan Sleva, OAQPS/USEPA/RTP

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