{
  "url": "https://openlegislation.uk/eu-decision-2002-657/annex/chapter-3.1/division-3.1.2.1",
  "json_url": "https://openlegislation.uk/eu-decision-2002-657/annex/chapter-3.1/division-3.1.2.1.json",
  "legislation": "eudn/2002/657",
  "legislation_title": "Commission Decision of 12 August 2002 implementing Council Directive 96/23/EC concerning the performance of analytical methods and the interpretation of results (notified under document number C(2002) 3044) (Text with EEA relevance) (2002/657/EC)",
  "legislation_url": "https://openlegislation.uk/eu-decision-2002-657",
  "path": "annex/chapter/3.1/division/3.1.2.1",
  "kind": "division",
  "number": "3.1.2.1",
  "heading": "Recovery",
  "text": "If there is no CRM available, the recovery has to be determined by experiments using fortified blank matrix using, for example, the following scheme:\nselect 18 aliquots of a blank material and fortify six aliquots at each of 1, 1,5 and 2 times the minimum required performance limit or 0,5, 1 and 1,5 times the permitted limit,\nanalyse the samples and calculate the concentration present in each sample,\nusing the equation below, calculate the recovery for each sample,\ncalculate the mean recovery and CV from the six results at each level,\n% Recovery = 100 × measured content/fortification level.\nThis conventional method for the determination of recovery is a variant of the standard addition method described in 3.5, when:\nthe sample is considered as a blank sample instead of a sample to be analysed,\nit is considered that yield and recovery are similar for the two test portions,\nthe test samples have the same masses and the test portion extracts the same volumes,\nthe amount of the calibration standard that is added to the second (spiked) test portion is noted xADD. (xADD = ρA.VA),\nx1 is the measured value for the blank and x2 the measured value for the second (spiked) test portion,\nthen, % Recovery = 100 (x2 - x1)/xADD.\nWhen any of the above conditions is (or is supposed) not to be achieved, then the complete procedure for determination of the recovery by mean of the standard addition method as described in 3.5 has to be performed.",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "footnote",
      "label": "f1",
      "text": "Yield: that fraction of mass of the analyte contained in the sample, which is present in the final extract."
    },
    {
      "type": "footnote",
      "label": "f2",
      "text": "Recovery (here): that fraction of mass of the analyte added to the sample, which is present in the final extract. Throughout the rest of the document it is assumed that yield and recovery are equal and therefore only the term ‘recovery’ is used."
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eudn/2002/657/annex/chapter/3.1/division/3.1.2.1",
    "retrieved_at": "2026-11-01T15:18:31.211349+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}