Author:

Date:

Working with Laboratories

Sample Collection/Submission, Laboratory Processes, and Report Interpretation

David Nadler

03 April 2014

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Topics for Discussion

Collection and Submission – Containers

– Preservatives

– Holding Times

– Paper Work

Laboratory Processes – What happens after my samples are delivered to the lab?

Interpreting the Results – What can and can’t the lab tell me?

– Canadian Drinking Water Quality Guidelines

– Reading my report

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Collection and Submission

Plastic is cheap, light and unbreakable but…

It can’t be cleaned for organics

It adds organic contaminants

Organics absorb, adhere and pass through

Glass is easy to clean for organics and is chemically inert but it is..

Heavy

Fragile

Difficult to clean for some inorganics

Expensive

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Collection and Submission

Filling the containers:

Choose day/time to avoid scheduling conflicts in laboratory

Wash your hands first, wear disposable gloves

Label first, use water-proof ink

Don’t rinse if preservative present

Fill to shoulder (exceptions – VOC (THM), Chlorine)

Use entire contents of preservative vial

Tight caps snugly but don’t overtighten

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Collection and Submission

Preservatives Preservatives are used to:

Prevent physical change

Prevent chemical change

Prevent biological degradation

Important Tips

Add preservatives immediately after filling the container

Liquid preservatives need to be added in the field, solid preservatives are added by MAXXAM (don’t rinse the bottles)

Use entire contents of vial for each sample (may need more for dirty or alkaline samples)

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Collection and Submission

Holding Times There should be no change in the sample between collection and analysis

Hold times vary substantially depending on the parameters and analyses required.

Tips:

Only valid if correct bottle and preservative are used

Clock starts ticking at sample collection

Time Sensitive Analyses (Microbiologicals, BOD, Nitrite, pH etc.)

– Do not ship on Fridays

– If you sample on a weekend, call a representative from your Project Management Team first!

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Collection and Submission

Chain of Custody Sample ID

Date & Time of Sampling

Source Details

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Collection and Submission

Couriers and Shipping

Use ice bags to keep samples below 10 degrees Celsius

Send via priority couriers to avoid hold time exceedances

Fill out chain-of-custody forms completely, including needed analyses

Ensure that chain-of-custody forms match sample labels and are included with the shipment

Plan shipments ahead to avoid complications

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Laboratory Processes

1) Sample Reception and Log-in

2) Preprocessing

3) Sample and QC Sample Preparation

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Laboratory Processes

4) Analysis of prepared samples and QC

5) Data upload, review, validation

6) Report Generation and Invoicing

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Laboratory Processes

1. Sample Reception & Log-In

• Unpacking • Inspection • Sample integrity checks • LIMS log-in

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Laboratory Processes

2. Preprocessing

Percent Moisture

Preservation

Compositing

Sub-sampling (air drying soils)

Aliquotting (pour-off waters)

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Laboratory Processes

3. Sample & QC Sample Preparation

•Specific to the analyses •Extractions prioritized to meet holding times •Batch sizes •Full QC is prepared on a batch basis

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Laboratory Processes

Sample Prep Example: Trace Metals in Water

Measure turbidity

Sample aliquot in digestion tube

Add nitric acid

Digest on hot block

Dilute to volume

Prepare QC samples in similar manner

Transfer digested samples to auto sampler for instrumental analysis

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Laboratory Processes

4. Sample Analysis – Inorganics

ICP – OES = inductively coupled plasma – optical emission spectrometer

ICP - MS = inductively coupled plasma – mass spectrometry

Automated colorimetry

Cold Vapour Atomic Fluorescence spectrometer

Automated flow analyzers

Depending on the analyte, a variety of inorganic instrumental methods are used:

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Report with measured absorbances

Pipetter

Reagent tray

Variable wavelength filter

Detector Cuvette rack containing samples and reagents

Mixing and Colour Development

Light source

Auto sampler vials containing water samples

Sample Analysis Example: Automated Colorimetry

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Laboratory Processes

5. Data Upload, Review, and Validation

Review of sample data

Check QA acceptance

Re-prep & re-analysis (if required)

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Laboratory Processes

6. Report Generation and Invoicing

Basis of reporting

Concentration units on reports (dry weight vs. wet weight or ‘as received’- tissues)

Detection limits

Include electronic data deliverables (EDD’s) such as WaterTrax.

7. Sample Disposal

Stored for at least one month (1 week for micro)

Samples emptied and containers recycled

Those with high levels of hazardous compounds are returned or disposed of appropriately

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Report Interpretation

The number one question people ask, the one thing everyone wants to know is:

“Is my water safe to drink?”

Maxxam has almost 3000 dedicated employees, approximately 30 laboratories, and hundreds of millions of dollars in analytical equipment devoted to determining that very thing.

Ironically, this is one question we cannot answer.

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Report Interpretation

Laboratories cannot interpret your results for you. Your local BC Ministry of Health Office is the only authority that

can confirm that your water is potable or safe to drink.

http://www.health.gov.bc.ca/protect/dw_index.html

http://www.hc-sc.gc.ca Laboratory reports provide results only on those parameters that have

been requested.

Test packages usually reflect the most common contaminants of concern based on the “Guidelines for Canadian Drinking Water Quality” published by Health Canada.

Reports can only say the reported results meet or do not meet the guidelines.

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Report Interpretation

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Report Interpretation

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Conclusion

Using the correct containers and preservatives will ensure the sample accurately represents the source.

Labelling containers and filling out Chain-of-Custody forms reduces errors, ensures your requests are understood, and your results are reported accurately.

If you have a specific concern with your drinking water make sure you talk to the lab before collecting your sample to be sure you have the right container and that it is included in your test package.

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Conclusion

Questions?