| Substance | Linear regression equations | R2 |
| Acetone | y = 0.0148x – 0.1280 | 0.9975 |
| Methanol | y = 0.0004x – 0.0121 | 0.9832 |
| Ethanol | y = 0.0038x – 0.0236 | 0.9897 |
| n-butanol | y = 0.0188x + 0.0103 | 0.9953 |
| Acetic acid | y = 0.0234x + 0.0659 | 0.9941 |
| Propionic acid | y = 0.0231x + 0.4244 | 0.9984 |
| Isobutyric acid | y = 0.0739x + 2.9494 | 0.9710 |
| Butyric acid | y = 0.0545x + 1.9410 | 0.9902 |
| Isovaleric acid | y = 0.1285x + 5.6741 | 0.9516 |
| Valeric acid | y = 0.1085x + 3.9121 | 0.9681 |
| Caproic acid | y = 0.0841x + 3.6989 | 0.9291 |