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Control Sample Failure Checklist

Good laboratories will report results within the manufacturers two standard deviation levels with a failure rate of <10 %.  If your laboratory is not achieving that or if your control sample results are failing the quality criteria that you have set:


1. Check that you are using the correct Reference Material (with a grade and matrix matching your samples).

2. Read the manufacturers certificate and make sure your Control Chart limits match or are within the Certificate limits.

3. Note: if your laboratory has developed a bias you will automatically see more failures.

-Check the product labeling to make sure you are using the correct Reference Material

1. Check that the Product Code on the packaging matches the Code in your QC program.

2. The Laboratory Pack (tub) containers have two labels. A small label with a batch and a tub number is put on the tub during batch production and will be correct. A large label is put on the tub during dispatch and also shows the product (batch) code. The batch code on the small label must correspond with the batch code on the large label (IF IT DOESN'T, IMMEDIATELY CONTACT AMIS). 

3. Explorer Packs have been repackaged from the original tubs. The Product Code is on the label. Sample values and limits must be taken from the certificate.

-Check you are using appropriate limits

1. Check that you have set appropriate limits for that Reference Material for your laboratory (from your own results).

2. Check that you are applying the appropriate rules to accept or to fail a run (ref to Westgard).

-You still have a problem:

4. If you can, run a multi-element scan to check that the reference material major and trace element chemistry matches that published in the certificate (IF IT DOESN'T, IMMEDIATELY CONTACT AMIS).

5. Check that the matrix of the Reference Material matches or is close to the matrix of your samples and that the appropriate analytical techniques, fluxes etc. have been used for your matrix.

-Feel free to check the mathematics on the certificate.

1. AMIS round robin data and statistics are published in the certificate and are available in a digital format on request.

2. AMIS round robin data and statistics are also available in the round robin proficiency report. These reports are made available to Laboratories that participate in the AMIS round robins and customers may ask Laboratory Managers to see this report.

-Contact AMIS

1. Find out, how much has been sold to other customers?

2. Have there been any complaints about the product?