Table 3.
LOQ for the free-form green tea catechin metabolites (related to sulfate or glucuronide forms) for each biological sample.
| LOQ |
|||
|---|---|---|---|
| Compound | Plasma |
Blister fluid |
Skin tissue biopsy |
| pmol/L | pmol/L | pmol/mg tissue | |
| EC | 2 | 20 | NA |
| 3′-O-Me EC | 1 | 20 | NA |
| 4′-O-Me EC | 0.1 | NA | 1 |
| EGC | 0.2 | 10 | NA |
| 3′-O-Me EGC | 1 | NA | NA |
| 4′-O-Me EGC | 0.6 | 230 | NA |
| ECG | 0.1 | NA | NA |
| EGCG | 0.1 | NA | NA |
| Gallic acid | 40 | 110 | NA |
| 3-O-Me gallic acid | 2 | 10 | 10 |
| Quercetin | 20 | 60 | 30 |
| Kaempferol | 110 | NA | NA |
| M6 | 3 | 30 | 9 |
| Syringic acid | 20 | 40 | NA |
| 3-Hydroxybenzoic acid | 5 | 30 | NA |
| Benzoic acid | 50 | 590 | NA |
| Hippuric acid | 0.4 | 40 | NA |
EC, epicatechin; ECG, epicatechin gallate; EGC, epigallocatechin; EGCG, epigallocatechin gallate; Me, methyl; NA, not assessed using free-form standards, as the free-form or associated sulfate or glucuronide form was not identified in a sample.