Table 7.
The absorbance of MO, MPA, CIT, CTV and CPA in individual standard solutions.
| Mycotoxin | Solvent | Conc., μg/mL | λmax/λref., nm | A (Average, n = 3) | CV, % | ||
|---|---|---|---|---|---|---|---|
| Fresh | 10 Months | 14 Months | |||||
| MO | MeOH | 5 | 227/245 | 0.60 | 0.66 (+10%) | 0.68 (+13%) | 6.4 |
| 259/245 | 0.03 | 0.01 | 0.02 | ||||
| CIT | MeOH | 20 | 211/280 | 2.28 | 2.37 (+4%) | 2.40 (+5%) | |
| 253/280 | 0.74 | 0.72 (−3%) | 0.73 (−1%) | 1.4 | |||
| 318/280 | 0.33 | 0.32 (−3%) | 0.33 | ||||
| MPA | ACN | 250 –storage * 2.5—UV-spec. |
214/350 | 2.45 | in 4 months**: 2.44 | n.a. | |
| 249/350 | 0.4 | 0.4 | n.a. | 0 | |||
| 303/350 | 0.13 | 0.13 | n.a | ||||
| CTV | MeOH | 20 | 233/500 | 0.70 | in 4 months: 0.68 | n.a. | |
| 286/500 | 1.18 | 1.17 | n.a. | 0.6 | |||
| 385/500 | 1.66 | 1.57 | n.a. | ||||
| CPA | MeOH | 20 | 222/350 | 2.68 | in 4 months: 2.75 | n.a. | |
| 281/350 | 1.43 | 1.44 | n.a. | 0.5 | |||
MeOH—methanol, ACN—acetonitrile, MO—moniliformin, CIT—citrinin, MPA—mycophenolic acid, CTV—citreoviridin, CPA—cyclopiazonic acid; CV—coefficient of variation of absorbance. *—MPA exhibits high absorptivity, aliquots of standard solution were diluted 100-fold each time before measurements; **—the total storage period for MPA, CTV and CPA was four months, thus spectra were obtained immediately after preparation and in four months.