January 2009
INVITATION

3rd Interlaboratory Study on Perfluorinated Compounds in Water, Fish and Sludge

We are pleased to announce the 3rd International Interlaboratory Study (ILS) on Perfluorinated Compounds (PFCs) in environmental samples. The 1st PFC ILS (2005) showed that intercomparability of analytical results for fish and water was relatively poor, emphasising the need for further analytical improvements. A follow-up study (2007) showed that accurate and precise analysis of PFCs in water and fish is feasible if several critical steps in the analysis are properly addressed, e.g. the use of high quality native standards and multiple mass labelled internal standards.This third study is organised in collaboration with QUASIMEME (www.QUASIMEME.org) and the NORMAN network of reference laboratories for monitoring emerging environmental pollutants (www.norman-network.net). 

OBJECTIVES
The objectives of this study are supporting laboratories to assess accuracy and consistency of their methods and to compare their performance with colleagues worldwide. A water and a fish sample will be distributed, similar to earlier studies. In addition (and for the first time), a sewage sludge test material will be distributed. 
 
PARTICIPANTS
The study is open for participants from commercial, academic and regulatory laboratories. 

STUDY DESIGN
Laboratories are asked to analyse at least PFOS and PFOA in the samples. In addition, laboratories may wish to analyse and submit data on other perfluorocarboxylic acids (PFCAs), perfluorinated sulfonates (PFSAs) and (substituted) perfluorooctane sulphonamide (PFOSA). 
The submitted data will be statistically analysed and z-scores will be calculated and reported. At the moment of data submission, participants are asked to provide a short description of methods used (e.g. extraction and clean-up conditions, use of internal standards). This allows a more in-depth analysis of the submitted data.

TEST MATERIALS
•	Water sample. 500 mL freshwater filtrated over 63 µm filters to remove particles and stored in a high-density polyethylene (HDPE) bottle.
•	Fish tissue sample. Approx. 65 gram fish muscle tissue. The homogenised tissue will be provided in a glass jar. The material has been sterilised. 
•	Sewage sludge sample. A dried and homogenised sewage sludge sample.
•	Standard solution. An ampoule with a standard solution containing 17 PFCs is kindly provided by Wellington Laboratories (www.well-labs.com).  
All environmental samples are naturally contaminated (i.e. no additional spiking took place in the preparation phase). The samples will be sent to the laboratories by courier. Detailed instructions on how to store and treat the samples and how to report the data will be sent with the sample shipment.

TIMETABLE 2009
January		Announcement and invitation
15 February		Deadline for registration
March			Shipment of samples	
15 June		Deadline for returning results
1 September		Draft report
November		Final report

PARTICIPATION FEE
The participation fee is € 950. This covers the preparation of the samples, transportation costs, statistical evaluation of the submitted data and a report describing the study approach and results, including suggestions for improvement. Each laboratory will receive their z-scores.  

HOW TO SUBSCRIBE?
If you are interested in joining this study, you are kindly asked to provide your details in the registration form and return your details not later than 15 February 2009. The invoice for the participation fee of €950 will be sent to you within a week after registration. Please return the completed form by e-mail to mrs. Ike van der Veen at Ike.van.der.veen@ivm.falw.vu.nl (tel. +31 20 598 4044).

WORKSHOP ON PFC ANALYSIS
The QUASIMEME organisation frequently organises workshops on analytical aspects of contaminants. Previous workshops have been a valuable platform for exchange of analytical information, both for beginning and experienced laboratories (please refer to www.QUASIMEME.org for reports on earlier workshops). A 2-day workshop on the analysis of PFCs in environmental matrices is scheduled for October 2009 in Amsterdam (dates will follow later). The program will include a presentation and discussion of the results of this interlaboratory study. More information will become available during spring 2009. Please note that the subscription to the PFC workshop is not included in the fee of this interlaboratory study. 

We look forward to your participation in this study. Should you have any question, please don’t hesitate to contact us. 

On behalf of the co-organisers, 

Stefan van Leeuwen

Institute for Environmental Studies
VU University
De Boelelaan 1085
1081 HV Amsterdam
Tel 020-5989545
Fax 020-5989553
Email: Stefan.van.Leeuwen@ivm.vu.nl