External quality assessment schemes


The Centre de toxicologie du Québec (CTQ) is a public organization that has been offering human toxicology expertise (environmental, clinical and occupational) to the provincial health network of Quebec (Canada) as well as to external clients from around the world since 1972. Our laboratory has ISO/IEC 17025 and CAN-P-43 accreditation. The CTQ’s staff of 50 works in the fields of general and clinical toxicology, analytical toxicology and biomedical technology. The CTQ is part of the Institut national de santé publique du Québec.

Since 1979, we have been operating permanent external quality assessment schemes that enable participating laboratories to evaluate the accuracy and precision of their analytical methods on a continuous basis.

Approximately 250 laboratories from 30 countries participate in these schemes.

We offer biological proficiency testing materials (PTMs) that are not freeze-dried at a very competitive rate. They are both stable and homogenous and delivered on time according to national and international guidelines. New analytes can be added to each of the schemes according to participant needs.

Participating laboratories receive a detailed statistical report for each of the rounds for an easy evaluation of their performance. An assigned value with an acceptable range is provided for each analyte.

Our six assessment schemes

  1. AMAP: AMAP Ring Test for Persistent Organic Pollutants in Human Serum
  2. Creatinine: Interlaboratory Comparison Program for Measurement of Serum Creatinine
  3. Dioxin Furans: Interlaboratory Comparison Program for Dioxin Furans in Serum
  4. OSEQAS: External Quality Assessment Scheme for Organic Substances in Urine
  5. PCI: Interlaboratory Comparison Program for Metals in Biological Matrices
  6. QMEQAS: Quebec Multielement External Quality Assessment Scheme

Preparing Proficiency Testing Materials (PTMs)

PTMs sold commercially are usually prepared by spiking an analyte into a biological matrix followed by freeze-drying. This process greatly alters the matrix, which significantly differs from human biological specimens.

This process is avoided within our schemes. Biological matrices such as blood, serum, urine and hair are all obtained from unexposed human volunteers. The bulk materials are first analyzed to determine the baseline values and then spiked, if necessary, based on the needs of the proficiency test.

PTMs are tested for their homogeneity before they are shipped to participants. When a new analyte is introduced into a scheme, a stability assessment is performed in order to ensure that the element of interest will be stable enough throughout the proficiency testing exercise.

PTMs that remain from past rounds are made available to any interested laboratories at a very competitive rate. Consult the list of available materials at: http://ctqvente.inspq.qc.ca/default.asp?Lg=ang

For any other questions or to obtain a quote:

1 418 650-5115 ext. 4649