Dapsone and Trimethoprim in swine muscle: new PTs

Trimethoprim is a derivate of diaminopyrimidines and it is generally used in association with Sulphonamides.

Dapsone is used in veterinary alone or in combination with Sulphonamides for its anti-inflammatory properties. Dapsone has a mechanism of action that is similar to the one of Sulphonamides. Dapsone is included in the Annex IV of the CE regulation n. 2377/90 as a pharmacologically active substance for which no maximum level can be fixed.

The residues of Dapsone and Trimethoprim are dangerous since they are potentially carcinogenic in humans.

Test Veritas always walks alongside its customers! The PT for the research of Sulphonamides in swine muscle is now combined with the PT for Dapsone and the PT for Trimethoprim, in order to help laboratories that decide to perform these analysis.

The new combinations PTs for M3303 in swine muscle will be structured as follows

  • M3303: for the research of Sulphonamides + Dapsone + Trimethoprim
  • M3303/S: only for the research of Sulphonamides
  • M3303/D: only for the research of Dapsone
  • M3303/T: only for the research of Trimethoprim


  • Test Material: swine muscle, 2 samples of 30g for confirmatory methods or 10g for screening methods
  • Molecules under study: sulfamethazine, sulfadimethoxine, sulfaquinoxaline, sulfamerazine, sulfadiazine, sulfadoxine, sulfamethoxypyridazine, sulfamethoxazole, sulfamonometoxine, sulfathiazole, dapsone, trimethoprim
  • Indicative concentration: < 300ppb or blank


  • Separate evaluation data for screening and confirmatory methods, with the assigned value deriving only from quantitative confirmatory results.
  • Even if you are evaluating a screening method, the PT simulates what you would do in your routine (comparing your results with the confirmatory ones).
  • The qualitative and semi-quantitative screening results receive evaluations provided with dedicated criteria. The quantitative screening results are evaluated also through z-score.
  • Our Test Material are lyophilized (to be tested after reconstitution), in order to guarantee the stability of the Test Materials, even for long shipment. In this way, regardless of the provenience of the laboratory, every participant can be sure to receive the exact same Test Material as the others. This will make the assigned value (obtained by consensus) more reliable and the evaluation more valid.
  • For this PT 2 different Test Materials are provided, (they can be both contaminated or one of them could be blank). In the PT, as in the routine, the laboratory technician does not know if he/she is testing a contaminated material or a blank material. Providing 2 different Test Materials, the laboratory could be assessed also for False Positive results or for how the method operates at different leves of concentrations.
  • Participants that use a confirmatory method, receive the information about a possible False Positive in the Final Report.

Do you want to participate?

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The PT M3303 in swine muscle will be provided in the Round of September 2023. The Test Materials will be shipped on September 18th 2023.

If you want to see more details about this or other PTs, such as the schedule, prices… go to this page to download the entire programme.

Here you can find information on HOW TO ORDER.

For any further information, do not hesitate to contact us at info@testveritas.com.

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