# Presentation: 247285

## Laboratory Evaluation Help Center

- Step-by-Step Guidance for “**Getting Data****”**

## Initial Data vs. On-going Data

- Before you select a lab, you review DATA representative of your analytes, matrices, concentrations and data quality.

**INTIAL**

**ON-GOING**

- Once the lab is selected, you continue to collect DATA or submit samples to assure the laboratory is maintaining your needed quality.

## INITIAL DATA

- When you send the laboratory your Project Analyte Form and the Cover Letter, you are asking them to provide method information and DATA.
- The project should collect lab data representative of their matrix, ranges, including all analytes, and within acceptable quality limits. It needs to be BLIND DATA.

## INITIAL DATA

- If the laboratory HAS data from blind proficiency test studies for your analytes of interest (like the WP or WS, Environment Canada, or the USGS SRS round robins)  and the data are representative of your concentration ranges – THEN YOU DO NOT HAVE TO SUBMIT SAMPLES TO THEM. JUST COLLECT THIS DATA.

## NO BLIND DATA

**If the lab does NOT have blind data for some of your analytes, or they do but it is at an inappropriate concentration range, you must submit blind samples to them.**

## WHAT IS BLIND DATA

**Blind data** come from quality control or assurance samples wherein the laboratory does not know the sample result. Examples of blind data are the results of round robin studies or proficiency test samples submitted by outside organizations for the purpose of performance assessment. The analyst does not know the expected concentration of these samples (single blind), and often does not even know they are test samples (double blind).

## WHAT BLIND DATA IS NOT

- Routine laboratory spike or blank samples are not blind. The analysts know the concentrations of these samples and know that they are check samples. They are treated differently than environmental samples. This is not the data you need.

## TWO TYPES OF BLIND

**Single blind samples** are samples where the lab does not know the true concentrations but does know the sample is a test sample. They may treat it with extra care knowing this.

## DOUBLE BLIND SAMPLES

**Double blind samples** are samples where the lab does not know the true concentrations AND does not even know the sample is a test sample. They will treat it the same as any other sample.

## REFERENCE MATERIALS

- Reference Materials are samples that are of a known and certified concentration. They have been tested extensively. Submitting reference materials blindly to the lab is the best test of true performance.

## WHERE DO I GET SAMPLES?

- Reference materials are available for many (not all) routine analyses.
- Standard Reference Water Samples – _[USGS SRS](http://bqs.usgs.gov/srs)_
- _[NIST](http://www.nist.gov/srm)__ – National Institute of Science and Technology._
- Environment Canada (_[certified reference materials](http://www.nwri.ca/nlet/crm-e.html)__; __[proficiency test samples](http://www.nwri.ca/nlet/prof-e.html)__)_
- Commercial Vendors
- Ask BQS for help if you can’t find a sample...

## WHAT DO I ASK FOR?

- The analytes of interest
- A concentration within your range of interest.
- Prepared as a sample in water (unless you want to spike samples yourself or you have a different matrix)
- Cost and delivery time
- Any Certificate of Analysis or verification that shows the ‘actual’ and exact concentration they prepared, not the concentration you asked for.

## How do I send to the Lab?

- Notify the laboratory that you will be sending in some samples.
- Do not identify them as test samples if you can help it.
- Either have the vendor mail them to the lab directly (a dead give away that these are test samples) or have the vendor mail them to you, and you disguise them as regular samples.

## WHAT DO I DO WITH THE DATA?

- Upload the data into the BQS database (under construction! – use email for now).
- Use the data to assess whether or not this laboratory is capable of  providing adequate data. You will verify this periodically with on-going test samples.

## END

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