Current Interlaboratory comparisons for Metals and Organic Contaminants

The implementation of accepted quality assurance practices to analytical chemistry is recognized as a prerequisite to producing data with known accuracy and precision. Regardless of the target analyte or sample type, quality assurance and quality control are the cornerstones to analytical data validation. In addition to daily internal performance verifications via reference materials, a good quality assurance plan should include regular external performance evaluations for an independent assessment of analytical proficiency. Intercomparison exercises serve as such an independent external assessment.

For nearly thirty years, MESL has conducted intercomparison exercises in association with UNEP’s Regional Seas Programme, and formerly with the UNESCO-IOC Global Investigation of the Pollution in the Marine Environment (GIPME) programme. MESL conducts both regional and global intercomparison exercises. For regional studies, the participation is generally limited; the objective of such a study is to provide participants with information on their analytical proficiency. For the global studies, the subject material is often sent out to ~200 laboratories world-wide. Participants in these studies are informed of their performance and at the same time take part in characterising a material that can later be used to validate the results obtained in their day-to-day analyses.

MESL organises two intercomparison exercises annually, one each for organic and inorganic contaminants. Of note, the inorganic study includes the determination of methylmercury.

Reference	Matrix	Type of analysis	Date
IAEA-436	Tuna	Metals and Methylmercury	Sample was distributed in September 2004, with results due in March 2005.
IAEA-435	Tuna	Petroleum and chlorinated hydrocarbons	Sample was distributed in October 2004, with results due in September 2005.