Scheme Information Sheets
UK NEQAS for Vitamin K
KEQAS Standard Reference Material-2 (SRM-2) is a serum reference material for validation of methods measuring vitamin K1 (phylloquinone). It is available to purchase from the Nutristasis Unit, Synnovis. Please contact Ella.freke@gstt.nhs.uk or Nathan.timbrell@gstt.nhs.uk for further information.
| Scheme Particulars | Indicative Details |
|---|---|
| Accreditation body | UKAS |
| ISO/IEC Accreditation status | ISO/IEC 17043:2023 |
| UKAS Accredited Proficiency Testing Provider No | 7860 |
| Objective of Scheme | Provides EQA coverage for Vitamin K1 and a number of pilot analytes (pilot analytes not accredited to ISO/IEC 17043). The Scheme is operated quarterly and the specimens are dispatched once per year, therefore the participant is required to store specimens in their freezer (-20 degrees Celsius or less) until the time of analysis |
| Pre-, Analytical, Post- status | Analytical |
| Number of distributions per year (nominal) | 4 |
| Specimens per distribution | 3 (2 for pilot analytes) |
| Number of Specimens per annum | 12 |
| Frequency of distribution | Quarterly |
| Scoring system | ABC |
| Material distributed | Single or Pooled, liquid serum with or without exogenous added analyte |
| Programme Director(s) / Organiser(s) | Rachel Marrington |
| Criteria for participation | All, but overseas by courier |
| Nominal sample volume (mL) | 1.8 |
| Sample presentation TACs | All analytes in the same tube |
| Data in Chemistry on-line Dashboard | Yes |
| Analyte | Approx Range | Default Units | Target Value | B Score Limit (%) | C Score Limit (%) |
|---|---|---|---|---|---|
| Vitamin K1 | 0 – 8 | ug/L | ALTM | 40.0 | 60.0 |
| † K1 (Pilot) | 0 – 8 | ug/L | ALTM | ~ | ~ |
| † K1 2,3-epoxide (Pilot) | 0 – 20 | ug/L | ALTM | ~ | ~ |
| † MK-4 (Pilot) | 0 – 20 | ug/L | ALTM | ~ | ~ |
| † MK-7 (Pilot) | 0 – 20 | ug/L | ALTM | ~ | ~ |
☨ Analyte not yet accredited to ISO/IEC 17043:2023
| Abbreviation | Expansion |
|---|---|
| ALTM | All Laboratory Trimmed Mean |
| GLTM | Group Laboratory Trimmed Mean – which is the Method Principle Mean |
| MLTM | Method Laboratory Trimmed Mean – usually a manufacturer system / analyser mean |
| XALTM | An external value that may be from a Reference Method System |
| OGLTM | A Method Principle Mean used as the target for all laboratories |
| OMLTM | A specific Method Mean used as a target for all laboratories |
| MED | Median |
- Vitamin K 2025 schedule 47 KB
