Table 1.
Recovery of the tested compounds in various coffee samples*.
| Compounds | Concentration (μg/mL) | Instant coffee mix |
Ready-to-drink coffee |
Roasted and ground coffee |
|||
|---|---|---|---|---|---|---|---|
| Recovery (%) | RSD (%) | Recovery (%) | RSD (%) | Recovery (%) | RSD (%) | ||
| 3-CQA | 48.0 | 107.3 | 0.30 | 106.5 | 1.66 | 102.5 | 2.99 |
| 24.0 | 98.2 | 1.64 | 99.4 | 1.33 | 94.9 | 3.38 | |
| 4.8 | 93.9 | 0.43 | 105.1 | 1.14 | 94.7 | 1.91 | |
| 4-CQA | 11.0 | 102.2 | 0.68 | 103.0 | 0.36 | 101.2 | 0.19 |
| 5-CQA | 5.5 | 104.1 | 1.11 | 102.7 | 0.76 | 101.5 | 0.49 |
| 3-FQA | 1.2 | 99.5 | 4.92 | 104.9 | 2.66 | 109.8 | 4.49 |
| 3,4-diCQA | 0.5 | 93.9 | 1.79 | 101.1 | 1.28 | 88.5 | 0.26 |
| 3,5-diCQA | 0.5 | 98.9 | 1.50 | 104.5 | 0.73 | 89.3 | 2.15 |
| 4,5-diCQA | 0.5 | 87.7 | 1.42 | 101.8 | 1.33 | 87.4 | 2.68 |
| Caffeine | 35.0 | 106.6 | 0.52 | 107.1 | 1.69 | 106.3 | 1.16 |
| 17.5 | 102.1 | 0.93 | 102.4 | 0.58 | 99.8 | 1.43 | |
| 3.5 | 100.3 | 1.01 | 98.8 | 0.49 | 98.6 | 3.06 | |
*
n = three independent samples individually extracted.