Announcement for Inter-laboratory Comparison on Iron and Fluoride in Water 2021

Announcement for Inter-laboratory Comparison on Iron and Fluoride in Water 2021


We hereby announce the 3rd Inter-laboratory Comparison on Water Quality Analysis, which is focused on the Proficiency Testing of Iron and Fluoride in Water. This activity is open to academic, regulatory as well as commercial laboratories world-wide, especially those from developing and emerging countries. The organizer of this project is CAS-TWAS Centre of Excellence for Water and Environment (CAS-TWAS CEWE) and Water Quality Analysis Laboratory, which both are established at the Research Center for Eco-Environmental Sciences (RCEES), Chinese Academy of Sciences (CAS). This project is supported by Certification and Accreditation Administration of People’s Republic of China (CNCA) and Alliance of International Science Organizations (ANSO).

A draft report will be available at the end of March 2022, and the final report will be available to the participants by April 2022. All the participants who have contributed to the results will receive a certificate of participation in the activity.

Announcement 2021 for Inter-laboratory Comparison.pdf


We encourage all laboratories working in this field to participate and assess their analytical performance. To do this, participants are requested to completely fill out the Registration Form and mark the desired items that you intend to determine. 

Test Samples 

The test samples for Iron are in concentrations of 0.30-1.0 mg/L with 2% nitric acid as matrix. 

The test samples for Fluoride are in concentrations of 1.0-2.0 mg/L with H2O as matrix.

The samples will be distributed by an international courier service to the participating laboratories.

Please Note:

In order to avoid delay or retention of the samples at customs, please inform us if there are import restrictions in your country for any of the samples. 


Instructions for analysis and reporting

Further detailed instructions and reporting forms will be sent by e-mail simultaneously with the dispatch of the samples in September 2021. 

In short, the participating laboratories should:

·      use your own standard operation procedures for pre-treatment and instrumental determination

·      use your own reference standards for identification and quantification

·      report one single concentration for each testing sample in each water matrix 

·      report limits of determination for all measured analytes 


 Time Schedule 

AnnouncementJuly 20th, 2021
Return of registration formAugust 30th, 2021
Shipment of test materialSeptember, 2021
Confirmation of receipt of test material by participantWithin 7 days after receipt
Reporting of test resultsWithin 30 days after receipt
Publication of draft report on web-siteMarch 2022
Final report available to all participantsApril 2022

Participation Fee

The participation fee for any combination of the analytes in one item is free.

As the inclusion of the matrix is new this year, all recipients of this invitation are encouraged to spread the words to possibly interested laboratories!


Co-ordinating Group

SI Ludan  

Phone: +86 10 62849800


Phone: +86 10 62849466 

E-mail Address

For all enquiries by e-mail, please use

Postal Address:

Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences

18# ShuangQing Road, Haidian District, Beijing, P.R.China, 100085