Kjeldahl Nitrogen, Total (TKN) - Water Supply (WS), proficiency testing material is produced in accordance with ISO/IEC 17043:2010. Also referred to as Potable Water or Water Supply sample, this sample is manufactured according to TNI requirements. However, please note, this sample may include non-TNI analytes as well. The lower criteria from the TNI tables mimic the levels common to drinking water samples.
Supelco® is a global proficiency testing (PT) provider that manufactures best-in-class environmental and pharmaceutical PT products. The PT portfolio allows our test components to offer significant performance data to monitor and prove competency to customers, accreditation bodies or both. These samples (WS Concentrates) are typically provided in duplicate for use in case of lab mishap, for QC purposes or to analyze multiple methods.
Type of PT Scheme: Water analysis - Water Supply (WS)
Matrix: Water Supply/Drinking Water Analyte/s: Values of analytes vary from lot to lot.
All information regarding the use of the Kjeldahl Nitrogen, Total (TKN) - Water Supply (WS) can be found in the reporting packet which will be available to download at PT Portal.
Kjeldahl Nitrogen, Total (TKN) is a parameter for evaluating the quality of water and environmental contamination specifically in water samples. Our product, Kjeldahl Nitrogen, Total (TKN) - Water Supply (WS) is a proficiency testing material used for the determination of total Kjeldahl nitrogen (TKN) and/or organic nitrogen in drinking water samples.
Have any questions? Explore our FAQs. For more information on this product, please contact our Technical Service team.
Features and Benefits
We have a vast portfolio of environmental PT schemes with "fit-for-purpose" samples to help you meet the needs of the laboratory.
Our proficiency testing (PT) program is a benchmark to:
provide staff with an insight into their laboratory′s performance, to verify the accuracy and reliability of their testing process
provide a comparison of performance with that of other laboratories, nationally and internationally
test and educate staff, provide a better understanding of the impact of incorrect results and identify areas where there may be problems
provide an independent evaluation of laboratory performance
demonstrate to clients, colleagues and accreditation bodies that there is a commitment to quality
PT sample is as a 2 mL concentrate.
The solvent for this sample is water.
The PT sample has been autoclaved for preservation.
Toprepare the solution, partially fill a 1000-mL volumetric flask with ammonia-free, reagent-grade water (near 20 °C).
Open ampule PE1575-2ML (be careful to avoid cuts on glass) and transfer 1.0 mL of concentrate to the volumetric flask.
Fill the volumetric flask to volume with reagent-grade water and mix well.
The sample is now ready for immediate analysis.
If a solution is not to be analyzed within two days after preparation, preserve a sample aliquot with 0.2 mL of concentrated sulfuric acid per 100 mL of sample (pH<2) and store at 4 °C until just before analysis. Analyze the preserved sample as soon as possible within the maximum 28-day holding time.
Storage and Stability
Please refer to sample label for expiration date, specific storage temperature, and specific storage conditions.
Are you new to Supelco® Proficiency TestingͰ Be sure to register your account details in the PT Portal before placing your order. This will provide access to data entry, reporting packets and final reports. Registrations will be approved shortly after your order is placed. For further questions, write to us at firstname.lastname@example.org.
When placing your order online, please indicate your study preference under the ′your reference′ column. Available studies can be viewed at the bottom of the page. Click here to learn more about Quick-Turn Studies (on-demand proficiency tests that are offered depending on lot availability). The Quick-Turn results are released within 48-72 hours whereas scheduled study reports are released within 21 days.
Proficiency testing samples are presented as single blind. No values for the samples are released until the testing period concludes.
Proficiency Testing Schedule (2022-2023)
Drinking Water WS22-2 March 23 - May 6, 2022 WS22-4 September 21 - November 4, 2022
WS23-2 March 22 – May 5, 2023 WS23-4 September 20 – November 3, 2023
Quick-Turn Study (on demand proficiency test that is offereddepending on lot availability)
Supelco is a registered trademark of Merck KGaA, Darmstadt, Germany
Kjeldahl nitrogen, total (TKN) 1.5-35 mg/L
Storage Class Code
12 - Non Combustible Liquids
Certificate of Analysis
Enter Lot Number to search for Certificate of Analysis (COA).
Certificate of Origin
Enter Lot Number to search for Certificate of Origin (COO).
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