EU legislation for pesticides
Hi all,
I hope you can help me to clarify this doubt.
The EU legislation for pesticides states for some PPP an MRL of 0.01* where the * is the lower limit of analytical determination.
Now I have received a certificate of analysis where:
the result is <0.01mg/kg,
the LOD is 0.004,
the LOQ is 0.01 mg/kg,
the MRL for the product as per EU legislation is 0.01*
Is LOD (limit of detection) the same as lower limit of determination?
Would you accept the product as complying with the EU legislation?
thanks
Hi all,
I hope you can help me to clarify this doubt.
The EU legislation for pesticides states for some PPP an MRL of 0.01* where the * is the lower limit of analytical determination.
Now I have received a certificate of analysis where:
the result is <0.01mg/kg,
the LOD is 0.004,
the LOQ is 0.01 mg/kg,
the MRL for the product as per EU legislation is 0.01*
Is LOD (limit of detection) the same as lower limit of determination?
Would you accept the product as complying with the EU legislation?
thanks
Hi Cuis,
Tricky.
One really needs to have related EU/Pesticide expertise to reliably answer yr query which I do not. IMO yr analytical laboratory should be the best source of relevant advice (or some other Expert Organization like Campden).
I offer the information below as speculative advice only.
The following attachment is the closest/most recent "official" document I could locate to assist in answering yr query.
Guidance Document, Pesticide Analytical Methods,2021.pdf 1MB 9 downloads
Sections 3.4 and 5.1.4 suggest (to me) that, based on the stated (and I assume validated) Certificate's LOQ value, the result in Certificate appears compliant to EU's stated MRL of (maximum) 0.01mg/kg.
I noticed one possible caveat to above in that the following attached document also included a (unreferenced) requirement that the LOD be < than 25% of the MRL which is not complied with in the current case. However this is an older study (2001) so may be obsolete in this respect. No numeric restrictions on LOD value are mentioned in the 1st attachment above.
Determination of Pesticides in Fruits and Vegetables by LC-MS.pdf 171.48KB 11 downloads
PS - JFI -
The key difference between LoD and LoQ is that LoD is the smallest concentration of an analyte in a test sample that we can easily distinguish from zero whereas LoQ is the smallest concentration of an analyte in a test sample that we can determine with acceptable repeatability and accuracy.
https://www.differen...een-lod-and-loq
Other inputs welcome of course.
The definition in Article 3(2)(f) of Regulation (EC) 396/2005:
'limit of determination' (LOD) means the validated lowest residue concentration which can be quantified and reported by routine monitoring with validated control methods.
Confusingly, most of the labs I've dealt with for pesticides (and indeed various other items of analytical chemistry) would call this the LOQ (limit of quantification), whereas for those labs the LOD refers to the limit of detection rather than determination - basically the final quote in the post from Charles above.
In the case of your results, it is therefore the LOQ figure that is equivalent to the limit of analytical determination mentioned in Regulation (EC) 396/2005.
If the laboratory have specifically stated <0.01, rather than "not detected", my default interpretation would be that they did get a positive detection of the relevant residue, but that the level was too low to quantify based on their LOQ of 0.01mg/kg. This would therefore be compliant with the MRL limit in regulation, assuming that (a) I've interpreted the presentation of the result correctly, and (b) there are no processing factors that would also need to be taken into account (i.e. you're testing fresh whole fruit/veg, rather than a processed or semi-processed product).
If you're not confident in the interpretation of the result then it's generally always a good idea to ask the lab to clarify. Many of the labs that offer this type of testing will also include a statement that, based on the results, a product is/isn't in conformity with Regulation (EC) 396/2005 - obviously the statement usually comes with an assortment of disclaimers, but can nonetheless potentially be a useful feature sometimes.
Thank you very much to both of you! I was puzzled with the definitions but pHruit comment about the limit of determination being called limit of quantification by the laboratories made it more clear.
Thank you very much to both of you! I was puzzled with the definitions but pHruit comment about the limit of determination being called limit of quantification by the laboratories made it more clear.
Hi Cuis,
Just to slightly expand Post 4. Afai can tell the confusion was (predictably?) originated by EU's quirky decision in Reg 396/2005 to introduce the phrase "Limit of Determination" (hence EU's LOD) to reference a defined quantity which, afaik, everybody else even then routinely called Limit of Quantification (hence LOQ). EU's choice thereby caused additional confusion since "LOD" was already routinely used by everybody else for a different defined quantity called "Limit of Detection" (hence Other's LOD).
The "illogicality" was seemingly (ca 15 years later !) quietly "corrected" by "EU" in statements like this -
LOQ(EU).PNG 51.93KB 0 downloads
LOD(2005),LOQ.PNG 72.2KB 0 downloads
(Sources -
pesticides_mrl_guidelines.2019_app-d.pdf 1.51MB 11 downloads
pesticides_mrl_guidelines_wrkdoc_2021-11312.pdf 1.57MB 12 downloads
Thank you Charles for the feedback, it's good to have the evidence!