General Information Proficiency Tests

Qlip organises a proficiency testing program for chemical and microbiological analyses in milk and dairy products. During a ring trial, identical sample material (called "sample set") is sent to the participating laboratories. The laboratories are expected to analyse the samples within an agreed period of time and send the results to the contact person of Qlip, as indicated in the instruction/result forms of each of these ring trials.

The aim of proficiency testing is to provide the participating laboratories with information about their performance (e.g. the accuracy, the repeatability or the detection limits of an analysis). The laboratories can use this information for quality assurance of their chemical and microbiological tests. Moreover, proficiency tests are essential for demonstrating the performance of a laboratory to third parties (e.g. to customers, to accreditation bodies or to other supervisory bodies).

Procedure for proficiency tests,

In accordance with the annual planning, the participants receive the samples for the proficiency tests for which they have registered, together with an accompanying letter. About a week before sending samples the participants receive the concerning instruction/result form by e-mail. Both the letter and the form contain instructions concerning, for example, the storage of the samples, the date of analysis and the required pre-treatment of the samples.

Participants are responsible to carry out the proficiency tests correctly taking into account the following:

  • Report date and time of receipt of the samples on the result form.
  • Report the temperature of the water sample at receipt on the result form. For microbiological samples the temperature at receipt has to be less than or equal to 5 degrees. Above this temperature the samples are not stable.
  • Report the date of analysis on the result form. For the microbiological ring trials the samples has to be analyzed within 48 hours after sending samples, because the samples are stable for 48 hours. Sample sending for microbiological ring trials is on Monday, this means the samples should be analyzed by Wednesday.
  • Report the applied method (ISO/IDF/NEN Standard, own method). For a correct interpretation of the results this is essential.
  • For the chemical ring trials the samples should be analyzed in duplicate.
  • For he microbiological ring trials samples should be analyzed in singular.

Failure to carry out the proficiency tests correctly will render the results unusable for assuring the quality of the performance of the participating laboratory.

The results of each of the ring trials will be jointly listed and a statistical evaluation will be carried out. During this process the results from the participant will be tested against the average of all participants, the consensus value. Confidentiality is maintained by annual random coding of the participating laboratories.

For each ring trial a report with the statistical evaluation will be sent to the participants within approximately 30 days after dispatch of the sample sets.

Quality assurance of proficiency tests

The organisation of the ring trials by Qlip is described in internal procedures which are part of their quality assurance system. Qlip continuously works on improving the proficiency tests. The quality of the sample material is, where possible, checked beforehand. If, for example during transport, unexpected problems arise then spare sample sets are available for the majority of each of the (chemical) proficiency tests.

Conditions for registration

  • Interested laboratories can register for participation in proficiency tests by means of the registration form. This form also lists the costs and the dates on which the samples for each ring trial will be dispatched.
  • When a laboratory registers for a proficiency test all rounds are obligatory.
  • It is possible to participate more than once for a certain proficiency test because it is desired to test more methods or technicians. In this case you have to change the number of sample sets on the registration form. Each sample set will be treated as a separate participation. Please note that you will be charged according to the rate indicated in the 3rd column for each sample set that you order.
  • During a year it is not possible to change your registration.
  • In case of less than 10 participants for a certain parameter the ring trial for that parameter can be cancelled.

Sample transport

Transport of the sample sets will be done by courier service. The transport costs will be charged to your company. Qlip accepts no liability for failure of the carrier. This also applies to delays due to problems with customs.

Export certificates and other customer documents

For transport of sample sets to participants outside the EU export certificates and sometimes other customer documents may be needed. The costs for these documents will be charged to your company.

Costs for participation

  • The costs for participating in the proficiency tests consist of an annual registration fee and the costs per ring trial. The annual registration fee is € 240,74 (excluding Dutch VAT). For the prices per ring trial you have to register here and we will contact you soon.
  • The registration fee will be charged in the beginning of 2015.

The costs per ring trial plus the additional transport costs and any costs concerning export certificates and customer documents will be charged after the reporting of the concerning ring trial.