Table 2.
Cathinone stability in solvents.
| Analyte | Solvent | Storage temperature (°C) | % Difference between days 0 and 30 | p-value | Stability call | First unstable day of analysis |
|---|---|---|---|---|---|---|
| Mephedrone | MeOH | 20 | 87.6 ± 3.9% | 3.27E-08 | Unstable | Day 3 |
| 4 | 51.3 ± 5.6% | 1.44E-05 | Unstable | Day 14 | ||
| −20 | 8.7 ± 7.5% | 8.41E-02 | Stable | – | ||
| ACN | 20 | 32.9 ± 9.7% | 5.23E-05 | Unstable | Day 30 | |
| 4 | 7.2 ± 14.2% | 3.77E-01 | Stable | – | ||
| −20 | 8.5 ± 3.3% | 5.04E-04 | Stable | – | ||
| Naphyrone | MeOH | 20 | 23.5 ± 30.3% | 8.84E-02 | Stable | – |
| 4 | 23.3 ± 2.7% | 1.65E-01 | Stable | – | ||
| −20 | 18.6 ± 4.6% | 6.44E-02 | Stable | – | ||
| ACN | 20 | 26.0 ± 1.7% | 1.94E-02 | Unstable | Day 30 | |
| 4 | 7.5 ± 3.8% | 1.14E-01 | Stable | – | ||
| −20 | 6.6 ± 7.3% | 4.80E-01 | Stable | – | ||
| MDPV | MeOH | 20 | 44.4 ± 10.7% | 1.84E-02 | Unstable | Day 3 |
| 4 | 32.1 ± 12.9% | 2.51E-02 | Unstable | Day 3 | ||
| −20 | 25.5 ± 9.5% | 4.80E-01 | Stable | – | ||
| ACN | 20 | 18.6 ± 12.1% | 6.79E-02 | Stable | – | |
| 4 | 12.1 ± 7.2% | 6.70E-02 | Stable | – | ||
| −20 | 10.4 ± 8.7% | 1.00E-02 | Stable | – | ||
| α-PVP | MeOH | 20 | 3.4 ± 39.7% | 5.77E-01 | Stable | – |
| 4 | 6.9 ± 12.2% | 4.02E-01 | Stable | – | ||
| −20 | 2.9 ± 5.1% | 4.61E-02 | Stable | – | ||
| ACN | 20 | 15.1 ± 4.3% | 4.81E-06 | Stable | – | |
| 4 | 7.5 ± 10.8% | 9.94E-06 | Stable | – | ||
| −20 | 50.9 ± 63.5% | 9.44E-01 | Stable | – |
Bold values indicate instability criteria were met (i.e., % change in concentration >= 20 and/or p < 0.05).