Proficiency testing (PT): Volatile Organic Compounds (VOCs) in natural waters

Distribution Schedule 2024

Round Registration
Final Report

Round November 2024 18/10/2024 04/11/2024 29/11/2024 16/12/2024
Registration Deadline: 18/10/2024
eCommerce Qualitycheck 2024 - Order Online

Scope of the Interlaboratory Proficiency Testing

The scope of this proficiency testing is the evaluation of the performance of laboratories for the determination of the Volatile Organic Compounds (VOCs) in natural waters (ex. groundwater, surface water, etc.).

Interlaboratory proficiency testing organized in accordance with the standard ISO/IEC 17043:2010 - Conformity assessment — General requirements for proficiency testing.


Aromatic solvents (CAS Number)
  • Benzene (71-43-2)
  • Ethylbenzene (100-41-4)
  • Styrene (100-42-5)
  • Toluene (108-88-3)
  • o-Xylene (95-47-6)
  • Xylene (m+p)*
  • Xylene (o+m+p)**
*: Xylene (m+p) - Sum of m-Xylene (108-38-3) and p-Xylene (106-42-3).
**: Xylene (o+m+p) - Sum of o-Xylene (95-47-6), m-Xylene (108-38-3) and p-Xylene (106-42-3).

Indicative concentration levels: 1 - 20 microg/L

Halogenated solvents (CAS Number)
  • Bromodichloromethane
  • Bromoform
  • Chloroform
  • Dibromochloromethane
  • Total Trihalomethane (THMs)***
  • 1,2-Dichloroethane
  • Hexachlorobutadiene
  • Tetrachlorethylene
  • Tetrachloromethane
  • Trichloroethylene
***: Total Trihalomethane - Sum of Chloroform (67-66-3), Bromoform (75-25-2), Dibromochloromethane (124-48-1) and Bromodichloromethane (75-27-4)

Indicative concentration levels: 1 - 20 microg/L

Proficiency test item:

  • 1 x 2000 mL of the test material to be prepared from a water matrix and a vial of the spiking solution for the determination of all parameters.

NOTE: All the details for the preparation of the final test sample are included in the Guide Lines of the interlaboratory proficiency testing provided with the test samples.

ADDITIONAL TEST SAMPLES: For costs and availability of additional test samples contact Qualitycheck (e-mail


The test sample should be analysed under the same conditions and with the same procedures used for the routine samples in the laboratory including the quality control procedures.

For each measurand shall be reported one result.

ADDITIONAL RESULTS: Each participant can submit up to 5 results* for the same analyte, thus obtaining an evaluation of laboratory performance for different operators, instruments and/or test methods (e.g. operator 1/operator 2, instrument A/instrument B, etc..).

eCommerce Qualitycheck 2024
Order Online Proficiency Testing

    Did you find this page helpful?


    *: Only one result submitted by the laboratory will be included in the statistical treatment of data for the calculation of the Assigned Value and statistics of data of the analyte, to avoid that a single laboratory has a different statistical weight, depending on the number of its submitted results. The additional results are evaluated by assigning z-score values, using the Assigned Value and the Standard Deviation for Proficiency Assessment obtained from statistical treatment.