About the analytes

Dithiocarbamates

Dithiocarbamates are compounds analoge of the carbamate group with the exception that the oxygen has been susbtituted by a sulfur atom, there are two types: mono and bisalkyl-dithiocarbamates d1. they are pesticides organophosphorated mainly used as fungicides and in some cases as mammal repelent d2, they are non-systemic pesticides and their residues can be mainly found in the surface of the crops. Thanks to the activity against a wide number of fungal diseases its use is extended to a high number of crops.d3,d4.

The current dithiocarbamates are: maneb, mancozeb, metiram, propineb, thiram and ziram.

Some of the dithiocarbamates show a certaing degree of toxicity to mammals, marine invertebrates, fishes, earthwoms and birds, depending on which dithiocarbamate is being considered d2 The main metabolites from dithiocarbamates area Ethyenthiourea (ETU) and Propylenthiourea (PTU) 4, these two metabolites has been found to be cancinogenic to rats 5 and inhibitors of the thyroid hormone and cause of some problems with the blood and liver 6, between another possible ppathogenic effects 4. The toxicity in the long term for mammals can affect the thyroids, but again, the toxicity depends on which dithiocarbamate we are refering to d7.

The current definition and way of reporting results for these pesticides are as "Dithiocarbamates (dithiocarbamates expressed as CS2, including maneb, mancozeb, metiram, propineb, thiram and ziram)"d8.

Some of the dificulties that this analysis shows is that due to the low solubility in multiresidues solvents and the low stability the require a single residue method d2,additionaly during the preparation of the sample up to a 100% of the dithiocarbamates can be lost if done at room temperture and if some artificial rubber is used there have been cases when they have contaminated the samples with dithiocarbamates, risking the possible false positive or erroneous results d9.

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

Download protocol

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 is specifided 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 can be found in the protocol.

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

The target analytes for this PT is specified in the protocol.

PT Scheduled calendar

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

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 our proficiency tests are based/accredited:

·UNE-EN ISO/IEC 17043:2010 General requirements for proficiency testing. Parameters marked with (*) are 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?

·Founded in 2003, almost 20 years of experience in proficiency tests.

·Posibility, if previously requested, to issue independent reports per analyte family (contact us to check options and availability).

· 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 we can of the shipping, so you can focus on the analysis.

·We are available at any time and any direct consult to TestQual usually has a response time below 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.

**PT is considered useful if a certain % (internally determined according to our procedure) of present/spiked analytes will be studied.

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.