*Proficiency test not accredited*

Glyphosate (*)

Glyphosate and other glyphosate-based plant protection products are mainly used to combat weeds that can compete with the target cultivated crops ^g1, g2 thanks to the herbicide mechanism that kills by inhibiting 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) that is necessary to produce key components for the plants. This inhibition can disrupt one of the main mechanisms that allows plants to fix more the carbon they require. ^g3

Enough levels of glyphosate has been found to be toxic to aquatic life with long lasting effects ^g2 and endocrine disruptor that can cause an oxidative stress due to the overload of Ca²⁺ that disrupts male reproductive functions in rats.^g4

For Glyphosate in the 2019 MRL review by EFSA different residue definitions were considered depending on if the crop was or not genetically modified to tolerate glyphosate. In this study it was considered that the main definition would depend on this, being Glyphosate a sufficient marker to monitor these levels on conventional crops but for genetically modified tolerant plant to glyphosate should defined and reported as: “sum of glyphosate, AMPA, N-Acetly-glyphosate and N-acetyl-AMPA, expressed as glyphosate”. ^g5

Ethephon

Ethephon is a organophosphated pesticide that causes inhibition of the chlonisterase in the human plasma.^e1 One of the metabolites is phosphonic acid and is instable in alkaline and oxidative mediums ^e2,e3,e4.

Is a plant growth regulator employed for the ripening and flower induction, between other uses. Its mechanism is through liberation of ethylene, chloride, and phosphate, which are absorbed by the plant, affecting the growing process. ^e4

This Pesticide is moderately toxic through oral, dermic and respiratory exporisiton, in addition to bien corrosive and causing irritation in the eyes and skin (according to study made on hares) and can cause  neurotoxic effects (as stated inhibition of the chlonisterase).^e4,e5

The ethephon LMR can be checked in the COMMISSION REGULATION (EU) 2015/399 of 25 February 2015 which is found here: EU LEX link.

Bromide

Methyl bromide have had various uses for it to be used as a pesticide and fumigate it, to mention some: as fungicide, herbicide, insecticide and some more, being fumigated in the soil or after crop-harvesting. ^b1

Additionally, is probable that a significative part of the methyl bromide is lost to the atmosphere during fumigation before it is re-captured, causing an unconfirmed environmental contamination that could not be confirmed and that should be minimized.

One of the fates of the Methyl bromide that arrived at the atmosphere is causing a negative impact in the ozone concentrations in the troposphere and stratosphere, both a very important filters of UV raditation. ^B2

With the goal of offering safe products and keeping habitants healthy the European union and the European Food Safety Authority (EFSA) issued an scientific opinion in which stated that a MRL should be stablished for methyl bromide, however, due to the low recoveries in vegetable matrixes a method could not be validated and given that this molecule cannot be included in a multiresidue analysis, the conclusion that the concentration of this molecule could not be controlled, at least in a direct way, however, the main metabolite of this molecule is bromide ion, which could be analysed in vegetable food (except food with high fat content). ^B6

However, it has to be taken into account that the presence of bromide is not limited by the metabolization of methyl bromide, it can be present by natural means, specially in sea water, therefore is the concentration in soul and vegetable products are expected between 1 and 20 mg/kg. ^B2

Due to the reasons above mentioned it was decided not to include Methyl Bromide in annex I of the directive 91/414/EEC and would not be allowed as a active material in Europe ^B4, but to controle it a MRL was stablished for bromide ion, which carries on until today. ^{B3, B5}

Why participate in a proficiency test?

There are many reasons to schedule these quality controls, the participation in international proficiency tests helps laboratories detect improvements and ensure the results are reliable.

As of today, one of the main goals for any laboratory is increase its client’s trust in their analysis procedure and results obtained, checking that equipment, personel, solvents and all the steps and parts involved in the analysis are working as intented, providing trustworthy and realiable results.

As a laboratory its is now more important than ever to be able to obtain results with precision and accuracy to help your clients commercialice products safe for the end-user.

The continuous participation in proficiency tests can help you detect bias and check if any change or improvement made as an effect on the results obtained.

TestQual's international proficiency tests are a great and reliable service to help you check your results against laboratories from all around the world, helping you detect any deviation to correct it and ensure your clients continuous quality controls and improvements are being monitored by participating and checking your results against other laboratories.

Summary of the proficiency test

All the information about this PT can be found in the protocol, which can be downloaded from a link located in the right column of this page. 

This proficiency test will consist in a single round with a single sample, the amount of sample to be distributed can be found in the protocol of this PT. If needed and justified, more amount of sample can be requested to the coordinator of the PT. Additional charges might apply.

The range of concentration for the target analytes of this proficiency test will be:

Approximately between 10 and 300 μg/kg (except sum parameters)

The target standard deviation for the analytes can be checked in the protocol.

For this PT the parameters to be analyzed are: 

PT Scheduled calendar

Check the right column of this page, in the “Dates” section.

*These dates are orientative and always will have to be checked in the protocol of the PT and the news in our webpage. Only participants inscribed in the proficiency test will receive the sample instructions/recommendations and the definitive date for the distribution of samples.

Accreditation and standards

·Standars in which this proficiency test is based/accredited:

·UNE-EN ISO/IEC 17043:2010 General requirements for proficiency testing. (Proficiency test NOT ACCREDITED). Check our scope of accreditation here.

·UNE-EN ISO/IEC 15328:2015 Statistical methods for use in proficiency testing by interlaboratory comparison

· HARMONIZED PROTOCOL FOR THE PROFICIENCY TESTING OF (CHEMICAL) ANALYTICAL LABORATORIES

·SANTE Guide into force: ANALYTICAL QUALITY CONTROL AND METHOD VALIDATION PROCEDURES FOR PESTICIDE RESIDUES ANALYSIS IN FOOD AND FEED

·Quick Method for the Analysis of Highly Polar Pesticides in Food Involving Extraction with Acidified Methanol a nd LC - or I CMS/MS Measurement - I. Food of Plant Origin (QuPPe-PO-Method) –Version 12 (published on EURL-SRM website on July 23, 2021); M. Anastassiades; A.-K. Wachtler; D. I. Kolberg; E. Eichhorn; H. Marks; A. Benkenstein; S. Zechmann; D. Mack; C. Wi ldgrube; A. Barth; I. Sigalov; S.Görlich; D.Dörk andG. Cerchia. URL: https://www.eurl-pesticides.eu/docs/public/tmplt_article.asp?CntID=887&LabID=200&Lang=EN

Why international proficiency tests with TestQual?

·18 years of experience in proficiency tests since our foundation.

·Posibility, if previously requested, to issue independent reports per analyte.

·International proficiency tests with participants from different countries (currently up to 5 continents).

·Transparency: Results from spiking and quality controls (homogeneity, stability) available for any participant that requests it.

·Expanding network of distributors to give a better client service, using local language and within your time zone. If your country still does not have a distributor, please, contact us, we can still accept your order.

·We take care of all aspects of the shipping, so you can focus on the analysis.

· We are available at any time and any direct consult to TestQual has an inferior response time of 24h (working days).

·We do not publish beforehand the price of shipping because we are constantly negotiating with providers and couriers to improve and adjust our prices. However, if you need a closed price in the quote and need to know the shipping costs, please, let us know and we will include it.

How to apply and get your laboratory code

Those laboratories that want to participate and are not registered on our website can register through this link: START REGISTRATION

If your laboratory is already registered on our website you can start your application by clicking the link situated at the top or bottom of this page, in PARTICIPATE, once you have logged in you will have to enter your Limit of Quantification (LOQ) for the parameters that have to be studied. The analytes with LOQ equal to NA (NOT ANALYSED) will NOT appear in the website when submitting the results of the PT.

Once the application has been sent, as soon as possible (usually 24h) you will receive an email with your laboratory code for the participation in the PT.

Contact us

If you have any doubt, if you want to get a quote or if we can help you in any other way, we are looking forward to helping you:

Thank you very much for your interest/trust in TestQual and our international proficiency tests.

If you want to receive a sample and participate click on the button "Participate" down below.