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Phosphonic acid in kaki and cucumber (P1411-MRT)

In 2013, phosphonates became an issue because of inclusion in EU Regulation (EC) No 1107/2009 as a pesticide. Moreover, phosphonic acid is regulated as the "sum of fosetyl and phosphorous acid and their salts, expressed as fosetyl" according to EU Regulation (EC) No 396/2005. Finally, a specific maximum residue level (MRL) has not been set up for phosphonic acid yet.

Salts of phosphonic acid, like potassium phosphonate, have previously been permitted for application in fertilizers and plant-strengthening products. Due to the persistence of phosphonic acid, residues might still be present in food products, although the last application of phosphonic acid was performed some time ago.

Up to now, no standardised method is available for the analysis of phosphonic acid in food products. This method ring test offers the opportunity to proof the reliability of the applied methods for the analysis of phosphonic acid in kaki and cucumber. The participants are requested to report details on their applied analytical method together with their analytical results. After evaluation of the results, the data are reported anonymised. This Method Ring Test will help to identify possible areas of improvement and to enhance the quality of the applied methods.

Two Test Materials were offered:

  • homogenate of kaki (ca. 180 g), spiked with K-Phosphonate
  • homogenate of cucumber (ca. 180 g), spiked with K-Phosphonate

The time schedule of the ring test was:

  • Dispatch of samples:                                   
    March 10,
  • Sample entrance (in the laboratory):
    March 11/12, 2014
  • Deadline for results reporting:
    March 31, 2014

Each participant was given a report after the evaluation of the analytical results. This report includes the anonymous results of all participants an the statistical evaluation of the data. 

Participation fee was 790 EUR. Blank materials were available upon request at a price of 70 EUR each.

Deadline for registration was February 25, 2014.

Summary of results