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Measurands currently available include: sodium, potassium, calcium, magnesium and lithium.
Future plans exist to transfer these methods onto an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) platform.
Measurand | Standard (certfied purity) | Control Material |
---|---|---|
Sodium | NIST 919B | NIST956d |
Potassium | Potassium Standard for AAS (Fluka TraceCert) | NIST956d |
Calcium | Calcium Standard for AAS (Fluka TraceCert) | NIST956d |
Magnesium | Magnesium Standard for AAS (Fluka TraceCert) | NIST956d |
Lithium | Lithium Standard for AAS (Fluka TraceCert) | NIST956d |
Cation | Sample pre-treatment | Technique | Wavelength (nm) |
---|---|---|---|
Sodium | 1/2025 dilution Ionisation suppressant (CsCl)* Surfactant (0.1% Triton) | Emission | 589.6 |
Potassium | 1/450 dilution | Emission | 766.5 |
Calcium | 1/25 dilution | Absorption | 422.7 |
Magnesium | 1/150 dilution | Absorption | 285.2 |
Lithium | 1/15 dilution | Absorption | 670.8 |
*2000 PPM, **1000 PPM
Measurand | Proposed AEmax(%) | Actual AEmax(%) | Proposed Biasmax(%) | Actual Biasmax(%) |
---|---|---|---|---|
Sodium | 1.3 | 0.8 | 0.5 | 0.2 |
Potassium | 2.0 | 1.7 | 0.8 | 0.7 |
Calcium | 1.7 | 1.1 | 0.5 | 0.4 |
Magnesium | 1.7 | 1.5 | 0.5 | 0.5 |
Lithium | 2.4 | 1.9 | 1.2 | 1.9 |
Theinpoint et al: Specifications for Reference Methods and Networks of Reference Laboratories from Members of the External Quality Assessment (EQA) Working Group B on target Values in EQAS. Eur J Clin Chem Clin Biochem 1995, 33:949-957.