From: "Susan Miller" <SMiller@bia.org>

To: Jeff Telander/RTP/USEPA/US@EPA

Cc: "Schimmel, Terry (Bricks

- Phenix City)" <Terry.Schimmel@boral.com>

Date: 10/21/2010 09:46 AM

Subject: FW: EPA Request for Additional Lab Info for ERT Submittal Bessemer

Attachments: Analytical Persoectives Determination of Detection Limits.pdf; Element
One Determination of Detection Limits.pdf; Enthalpy Analytical
Determination of Detection Limits.pdf

Jeff

-

Terry asked me to go ahead and send this to you. We are still trying to make sure we understand a few
things on our end. I have included our issues here

- your guys may actually be able to clear them up...

susan

From: Susan Miller

Sent: Wednesday, October 20, 2010 12:37 PM

To: 'Schimmel, Terry (Bricks

- Phenix City)'

Cc: Irene Kuo
Subject: RE: EPA Request for Additional Lab Info for ERT Submittal Bessemer

Still waiting to hear from Mike

- but here are our que stions...

- Last paragraph on “Element 1 detection limit discussion” is a bit confusing

- On that same page , it looks like they may be calling something a Method Detection that we

believe sounds

more like the Analytical Detection Limit

- but we could be off... we see the hierarchy as instrument,
analytical,
method, reporting....we need to be sure that we are all using the same one.

- In the equation for detection limit from Analytical Perspect ives, we are not sure which of the

above limits
they are calling “detection limit” (instrument?)

- Would like to hear from Mike as to whether the PM blanks and detection limit is how he thinks it

should be

done. I know he believes that Belden ’s test was not correct.From: Keith Poole

To: Schimmel, Terry (Bricks

- Phenix City)

Cc: Dan McCombs ; Troy Burrows ; Tasso Stratas

Sent: Tue Oct 19 14:05:23 2010
Subject: EPA Request for Additional Lab Info for ERT Submittal Besse mer

Terry,

I have finally compiled all of the responses from our sub

- contract partners regarding detection limit

determinations.

Please let me know if anything additional is required.

Regards,

W. Keith Poole, QSTI

Sr. Projec t Manager
mail to: kpoole@entecservices.com
704.938.8528 (Kannapolis, NC Office)
704.796.8164 (Cell phone)

* Baton Rouge, LA * Birmingham, AL * Mobile, AL * Raleigh (RTP), NC *

www.entecservices.com

2008, 2009 & 2010 Inc. 5000 Fastest Growing Small Business1 

### Keith Poole

From: Heather Steele [hsteele@ultratrace.com]

Sent: Tuesday, October 19, 2010 9:11 AM

To: Keith Poole Subject: Detection Limits



### Dear Keith:

Our detection limits are determined using the equation:

DL = ( 2.5 × H N 

### × Q IS 

### ) / ( H IS 

### × W × RRF)

In the equation:

 DL is the estimated detection limit for homologous 2,3,7,8-substituted PCDD/PCDFs

 H N 

### is the height of the noise (using 20-30 data points to determine σ , with 4 σ used as the value)

 Q IS 

### is the amount (in pg) of extraction standa rd added to the samp le before extraction

 H IS 

### is the peak height of the extraction standard

 W is the weight of the sample (for me thod 23 samples this value is always 1)

 RRF is the calculated relative re sponse factor for the analyte

Please let me know if you have any questions or if you need any additional information.

Heather



### Heather Steele PhD Project Manager Analytical Perspectives 2714 Exchange Dr. Wilmington, NC. 28405 (910)-794-1613 Ext: 110

This message, together with any attachments, is intended only for the use of the individual or entity to which it is addressed and contains information that is legally privileged, confidential and exempt from disclosure. If you are not the intended recipient, you are hereby notified that any di ssemination, distribution, or copying of this message, or any attachment, is strictly prohibited. If you have received this message in error, please notify the originat or immediately by telephone, fax or by return E-mail and delete/destroy this message, along with any attachments. Thank youThe Laboratory Certification Code requires a labo ratory to statistically determine its detection limits. Element One, Inc. conforms to these guide lines as follows:

Instrument Detection Limit (IDL) is the concentration equivalent to a signal, produced by the analyte of interest, which is the smallest signal that can be distinguished from background noise by a particular instrument. The IDL should always be below the method detection limit. It is not used for compliance data reporting, but may be used for statistical data analysis and comparing

the attributes of different instruments.

The IDL calculation is determined by analyzin g 10 blanks on three nonconsecutive days, pooling the data from all days. From the IDL data an esti mated detection level is chosen that is 1-10

times the IDL. Since the MDL is an estimate for the lower level of the calibration curve, the best spiking level is 1 - 5 times the estimated detecti on level, as specified in the EPA procedure.

Method Detection Limit (MDL) is the minimum concentration of a substance that can be measured and reported with 99% c onfidence that the analyte concent ration is greater than zero. It is determined by analysis of a sample in a giv en matrix which contains the analyte. The MDL is based upon the variability, or precision, between seven or more replicates run at identical

concentrations.

Method detection limits change over time for a variet y of reasons; therefore, it is necessary to periodically update the calculated MDL value. M any analytical methods require that the MDL be determined prior to using a new analytical syst em, and some even require annual updates. Element One verifies MDLs every six months, when new analysts are trained, and when new instruments are obtained. The frequency of the determination specified in the analytical method

is followed.

Reporting limits for Element One are set higher than the MDL using the lowest calibration

standard. The MDL can be used as the reporting limit if reproduci bility is proven by a valid study with seven replicates of the specific target co ncentration. No values are reported below the lowest calibration standard (reporting limit), unless a standard is prepared at that concentration and falls within a +/- 25% window. The Reporting Limit is an arbitrary number below which data is not reported. The reporting limits used by Elem ent One are not statistically determined, but are based upon experience and judgment of the analyst. Analytical results below the reporting limit are expressed using the lowest calibration point fo r calculating the "less than" reported. Reporting limits are not substituted for the laboratory es tablished detection limits. We do; however, occasionally reduce our reporting limit subs equent to having established lower values.

Element One Determination of Detection Limits 10. 08.09 Initial Version.doc1 

### Keith Poole

From: Jordan Laster [jordan.laster@enthalpy.com]

Sent: Tuesday, October 19, 2010 9:20 AM

To: Keith Poole Subject: Minimum Detection Levels

Keith -

For instrumental analysis (Such as EPA Me thod 26) the MDLs are determined by the analysis of at least seven replicate standards at a concentration near the expected MDL. To determi ne the MDL value, the standar d deviation of the replicate analyses is calculated and that number is multiplied by the "St udent t factor" that corresponds to the number of replicates analyzed. The MDL value should meet the crit eria stated in the CFR Title 40, Part 136 B.

If the MDL determined does not meet these criteria, a default MDL value will be used which is 1/10 of the concentration of the standard used to produce the MDL value.

For particulate analysis, there is no detection level determination. All samples are weighed on a 5 or 6 place balance (10 microgram increments) which far exceeds the method requireme nts for variability between weights. The methods specify a constant weight as being no more than 0.5mg difference between measurements. Therefore, this is the most appropriate detection level if one must be reported.

Let me know if you have any questi ons or need any other information.

-Jordan

Jordan Laster - Sales / Engineer Enthalpy Analytical Inc. 2202 Ellis Rd, Durham, NC jordan.laster@enthalpy.com

V: 919-850-4392 x300

M: 919-699-9991

F: 919-850-9012