Introduction
Materials and methods
Chemicals and reagents
Preparation of quality control samples and calibration standards
Sample preparation
UHPLC–MS/MS conditions
Compound | Retention time (min) | Precursor ion (m/z) | Product iona (m/z) | Collision energy (eV) |
---|---|---|---|---|
α-Solanine | 5.08 | 868.40 |
398.05
| 75.5 |
98.05 | 86.5 | |||
α-Chaconine | 5.08 | 852.40 |
706.40
| 72.5 |
98.10 | 86.1 | |||
Tomatidine (IS) | 6.42 | 416.40 |
255.30
| 33.0 |
161.05 | 39.0 |
Validation of the method
Case report
Results and discussion
Method development
UHPLC–MS/MS procedure
Method validation
Compound | Calibration curvea | Correlation coefficient (r) | Concentration range (µg/L) | LOD (µg/L) | LLOQ (µg/L) |
---|---|---|---|---|---|
α-Solanine | y = 0.0352x–0.00298 | 0.999 | 2–100 | 1 | 2 |
α-Chaconine | y = 0.161x–0.00679 | 0.999 | 2–100 | 1 | 2 |
Compound | QC concentration (µg/L) | Matrix effecta (%) | Recoveryb (%) |
---|---|---|---|
α-Solanine | 2 (LLOQ) | 107.9 ± 3.5 | 98.6 ± 6.8 |
8 (low) | 93.3 ± 3.3 | 103.9 ± 6.2 | |
40 (medium) | 88.4 ± 4.6 | 98.8 ± 3.2 | |
80 (high) | 83.6 ± 4.2 | 95.2 ± 3.1 | |
α-Chaconine | 2 (LLOQ) | 106.5 ± 3.5 | 90.2 ± 4.3 |
8 (low) | 87.6 ± 0.7 | 97.3 ± 2.8 | |
40 (medium) | 104.0 ± 4.6 | 83.8 ± 2.2 | |
80 (high) | 106.7 ± 12.1 | 84.2 ± 1.3 |
Compound | QC concentration (µg/L) | Intra-day | Inter-day | ||
---|---|---|---|---|---|
Accuracy (%) | CV (%) | Accuracy (%) | CV (%) | ||
α-Solanine | 2 (LLOQ) | 95.9 | 4.8 | 106.6 | 6.8 |
8 (low) | 96.3 | 9.4 | 93.5 | 5.7 | |
40 (medium) | 103.0 | 3.5 | 99.6 | 2.9 | |
80 (high) | 101.1 | 3.1 | 101.6 | 2.0 | |
α-Chaconine | 2 (LLOQ) | 99.4 | 3.3 | 107.6 | 3.6 |
8 (low) | 93.9 | 1.7 | 97.6 | 1.5 | |
40 (medium) | 100.5 | 2.6 | 98.2 | 1.3 | |
80 (high) | 99.5 | 1.3 | 101.0 | 1.6 |
Compound | QC correlation (µg/L) | RT for 24 h | 4 °C for 7 days | − 20 °C for 4 weeks | 3 Freeze–thaw cycles | ||||
---|---|---|---|---|---|---|---|---|---|
Mean ± S.D.(µg/L) | Stability (%)a | Mean ± S.D.(µg/L) | Stability (%)a | Mean ± S.D.(µg/L) | Stability (%)a | Mean ± S.D.(µg/L) | Stability (%)a | ||
α-Solanine | 2 (LLOQ) | 1.79 ± 0.12 | 89.5 | 1.93 ± 0.10 | 96.6 | 2.02 ± 0.11 | 101.1 | 2.06 ± 0.05 | 102.8 |
8 (Low) | 6.84 ± 0.95 | 85.5 | 6.84 ± 0.44 | 85.5 | 6.84 ± 0.43 | 85.5 | 6.87 ± 0.26 | 85.9 | |
40 (medium) | 40.5 ± 0.64 | 101.1 | 34.8 ± 0.88 | 87.1 | 41.1 ± 0.67 | 102.7 | 35.6 ± 1.27 | 89.0 | |
80 (high) | 83.4 ± 0.30 | 104.2 | 73.4 ± 1.44 | 91.8 | 79.7 ± 0.42 | 99.6 | 78.7 ± 1.03 | 98.4 | |
α-Chaconine | 2 (LLOQ) | 1.72 ± 0.04 | 85.8 | 1.7 ± 0.04 | 85.1 | 1.8 ± 0.07 | 89.8 | 1.76 ± 0.08 | 88.0 |
8 (low) | 7.29 ± 0.03 | 91.1 | 7.51 ± 0.15 | 93.9 | 7.49 ± 0.27 | 93.6 | 7.04 ± 0.31 | 88.0 | |
40 (medium) | 39.4 ± 0.26 | 98.1 | 37.0 ± 0.58 | 92.6 | 39.6 ± 0.18 | 98.9 | 35.4 ± 0.38 | 88.5 | |
80 (high) | 79.8 ± 0.68 | 99.8 | 72.1 ± 0.74 | 90.1 | 78.7 ± 0.22 | 98.3 | 76.5 ± 2.77 | 95.6 |