pISSN 2234-3806eISSN 2234-3814
Comparison of calibration levels for multiple LC-MS/MS assays*
| Reference | [43] | [44] | [45] | [46] | [47] | [48] | [49] | ||
|---|---|---|---|---|---|---|---|---|---|
| Assay | Whole blood cannabis | T4 and T3 in tissue | Thiopurine metabolites in red blood cells | Plasma metanephrines | Vitamin D in serum | Steroids in serum | Alpha fetoprotein in serum | ||
| Compounds | THC, 11-OH-THC, THCCOOH, CBD, and CBN | T4 and T3 | 6-TGN and 6-MMPN | Met, Normet | 25-OH-Vit D 3 | Androstenedione, DHEA, and testosterone | AFP-L3 | ||
| Calibrator | All analytes (ng/mL) |
All analytes (ng/mL) |
6-TGN (μmol/L) |
6-MMPN (μmol/L) |
Met (nM) |
Normet (nM) |
25-OH-Vit D 3 (nM) |
All analytes ng/L (pg/mL) |
AFP-L3 (ng/mL) |
| 1 | 0.5 | 0.2 | 0.5 | 5 | 0.04 | 0.08 | 25 | 50 | 0.051 |
| 2 | 1 | 0.5 | 2 | 20 | 0.4 | 0.8 | 100 | 0.256 | |
| 3 | 2 | 1 | 4 | 40 | 2 | 4 | 250 | 1.28 | |
| 4 | 5 | 2 | 6 | 60 | 10 | 20 | 800 | 6.4 | |
| 5 | 10 | 5 | 8 | 80 | 50 | 100 | 1,200 | 32 | |
| 6 | 20 | 10 | 10 | 100 | 2,000 | 160 | |||
| 7 | 50 | 20 | 800 | ||||||
| 8 | 100 | 50 | 4,000 | ||||||
| 9 | 250 | ||||||||
| Range (fold) | 500 | 250 | 20 | 20 | 1,250 | 1,250 | NA | 40 | 80,000 |
*Note the diversity of quantity and distribution of standard curve points relative to the range measured; †Calibrator values are a relationship of a single analyte concentration with varying labeled peptide internal standard concentrations.
Abbreviations: LC-MS/MS, liquid chromatography-tandem mass spectrometry; Met, metanephrine; Normet, normetanephrine; THC, tetrahydrocannabinol; 11-OH-THC, 11-hydroxy-tetrahydrocannabinol; THCCOOH, 11-nor-9-carboxy-tetrahydrocannabinol; CBD, cannibidiol; CBN, cannabinol; T4, thyroxine; T3, triiodothryonine; 6-TGN, 6-thioguanine nucleotides; 6-MMPN, 6-methylmercaptopurine nucleotides; DHEA, dehydroepiandrosterone; AFP, alphafeto protein; NA, not applicable.
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