Figure 1
Chemical structures of EU-regulated mycotoxins (excluding ergot alkaloids)
Table 1
Preparation of the multi-mycotoxin standard solution
| Analyte | Concentration of analytical standard (μ/mL) | Volume of analytical standard for preparation of 1000 μL of combined multi-mycotoxin standard solution* (μL) | Concentration of combined multi-mycotoxin standard solution (ng/mL) | Concentration of 100× diluted combined multi-mycotoxin standard solution (ng/mL) |
|---|---|---|---|---|
| DON | 100 | 50 | 5000 | 50 |
| AFB1 | 2.0 | 25 | 50 | 0.5 |
| AFB2 | 0.5 | 25 | 12.5 | 0.125 |
| AFG1 | 2.0 | 25 | 50 | 0.5 |
| AFG2 | 0.5 | 25 | 12.5 | 0.125 |
| FB1 | 50 | 75 | 3750 | 37.5 |
| FB2 | 50 | 75 | 3750 | 37.5 |
| ZEA | 100 | 7.5 | 750 | 7.5 |
| T-2 | 100 | 2.5 | 250 | 2.5 |
| HT-2 | 100 | 2.5 | 250 | 2.5 |
| OTA | 10 | 2.5 | 25 | 0.25 |
| Volume of combined multi-mycotoxin standard solution for preparation of 1000 μL of 100× diluted combined multi-mycotoxin standard solution** (μL) | 10 | |||
Figure 2
Microfiltrate preparation. Filtrate solutions (vials) 1 and 2 were injected into the UHPLC column one at a time
Table 2
MS/MS parameters for mycotoxin analysis
| Mycotoxin | Precursor ion m/z | Cone voltage V | Collision energy V | Product ions m/z |
|---|---|---|---|---|
| AFB1 | 313.2 (M+H)+ | 60 | 38 | 241.0 |
| 23 | 285.3 | |||
| AFB2 | 315.2 (M+H)+ | 60 | 30 | 259.0 |
| 25 | 287.0 | |||
| AFG1 | 329.2 (M+H)+ | 60 | 28 | 311.0 |
| 24 | 243.0 | |||
| AFG2 | 331.2 (M+H)+ | 60 | 24 | 313.0 |
| 28 | 245.1 | |||
| DON | 297.2 (M+H)+ | 25 | 10 | 249.0 |
| 10 | 203.2 | |||
| FB1 | 722.4 (M+H)+ | 50 | 40 | 334.3 |
| 40 | 352.3 | |||
| FB2 | 706.4 (M+H)+ | 50 | 40 | 336.2 |
| 40 | 318.2 | |||
| ZEA | 317.1 (M–H)- | -58 | 30 | 131.0 |
| 20 | 175.0 | |||
| T-2 | 484.7 (M+NH4)+ | 25 | 20 | 185.0 |
| 25 | 215.0 | |||
| HT-2 | 442.6 (M+NH4)+ | 25 | 10 | 263.4 |
| 15 | 215.3 | |||
| OTA | 404.1 (M+H)+ | 30 | 24 | 239.0 |
| 14 | 358.0 |
Figure 3
UHPLC-MS/MS chromatogram of the selected EU-regulated mycotoxins in the unfiltered multi-mycotoxin standard solution (AFB1/AFG1 0.5 ng/mL, AFB2/AFG2 0.125 ng/mL, DON 50 ng/mL, FB1/FB2 37.5 ng/mL, ZEA 7.5 ng/mL, T-2/HT-2 2.5 ng/mL and OTA 0.25 ng/mL) obtained with an Acquity H-class – Xevo TQ-S micro system
Figure 4
Recoveries of mycotoxins with various filter membrane materials in filtrate solution 1 and 2 relative to the recovery (dashed line) from the unfiltered multi-mycotoxin solution. Low recoveries indicating mycotoxin loss during filtration are framed in squares. CA – cellulose acetate; MCE – mixed cellulose ester; NY – nylon; PES – polyethersulphone; PTFE – polytetrafluoroethylene
Figure 5
Relative recovery of the 11 mycotoxins in filtrate solutions 1 and 2 by filter membrane material. CA – cellulose acetate; FS1 – filtrate solution 1 (first three drops of the solution); FS2 – filtrate solution 2 (the rest of the solution); MCE – mixed cellulose ester; NY – nylon; PES – polyethersulphone; PTFE – polytetrafluoroethylene
Figure 6
Relative recovery of the “outlier” mycotoxins AFB2 (a) and HT-2 (b) from filtrate solutions 1 and 2 by filter membrane materials. CA – cellulose acetate; FS1 – filtrate solution 1 (first three drops of the solution); FS2 – filtrate solution 2 (the rest of the solution); MCE – mixed cellulose ester; NY – nylon; PES – polyethersulphone; PTFE – polytetrafluoroethylene