Table 2. HPLC-ESI-MS/MS optimized instrument parameters and recovery (%), repeatability (SD%), LOD and LOQ of OTA, OTB and citrinin spiked in winter wheat flour.
| Parameter | Unit | OTA | OTB | citrinin | OTA 13C20 1 |
|---|---|---|---|---|---|
| tR2 | (min) | 12 | 11.1 | 11.6 | 12 |
| Precursor ion3 | (m/z) | 404.2 [M+H]+ | 370.1 [M+H]+ | 251.1 [M+H]+ | 424.2 [M+H]+ |
| DP3 | (V) | 44 | 37 | 22 | 44 |
| Product ion3 | (m/z) | 239.0/358.0 | 205.1/103.0 | 191.0/205.2/233.1 | 250.0/377.3 |
| CE3 | (V) | 34/20 | 32/76 | 33/33/33 | 31/19 |
| CXP3 | (V) | 17/36 | 17/17 | 17/17/17 | 33/34 |
| Recovery ±SD4 | % | 104±5 | 88±7 | 105±4 | |
| Linearity range5 | ng/g | 0.1–4.0 | 0.1–4.0 | 0.1–4.0 | |
| LOD±SD5 | ng/g | 0.3±0.1 | 0.5±0.2 | 0.6±0.1 | |
| LOQ±SD5 | ng/g | 0.8±0.3 | 1.1±0.4 | 1.4±0.3 |
1Internal standard;
2 Retention times obtained from 4 ng/mL solutions injected into the HPLC;
3Determined by direction infusion of 6 ng/mL toxin solutions in a 50/50 Eluent A/B mixture; Quantifier ion data in bold;
4Recovery was determined by spiking mycotoxins at 0.5ng/g and equilibrated for 3 days at 40°C before extraction (n = 3);
5Matrix-matched calibration curve (n = 6) was employed to determine level of detection (LOD) and quantitation (LOQ).