I mentioned that I'd researched into the melting points of mycotoxins before. As you can imagine, it was painstaking work researching one mycotoxin at a time. Here's the data that I saved back then.
The technical data that I've read states that THC and CBD melt at 80 °C and 66 °C, respectively. I could only find four mycotoxins that had melting points even remotely close to that. All the other mycotoxins had melting points considerably higher.
Trichothecin, Fusarenon-X, Patulin and Citreoviridin had by far the lowest melting points (118°C, 91-92°C, 110-111°C and 110°C respectively) of all the mycotoxins I researched. Neither of which are as low as the melting points of THC and CBD but perhaps close enough to warrant some consideration. Fortunately, only Trichothecin is soluble in hexane and pentane and it has the highest melting point of the four. The other three are insoluble in hexane and pentane and would therefore almost certainly be insoluble in butane, which is the next closest alkane.
Trichothecin is produced by Trichothecium Roseum, which causes pink rot. Pink rot isn't very common in cannabis and tricothecin isn't a particularly toxic mycotoxin but you should probably think again about extracting with butane from anything with pink/orange bud rot.
Aside from that, it would be a case of extracting with butane, to stop the other three mycotoxins mentioned from being extracted. All of the others listed have melting points considerably higher than the cannabinoids and shouldn't vaporize freely, providing that you vaporize your extract gently (<200°C).
Melting points of mycotoxins:
Aflatoxin B1 - 268 - 269 °C, degraded at 160 °C
Aflatoxin B2 - 286-289 °C
Aflatoxin G1 - 244-246 °C
Aflatoxin G2 - 230 °C
Aflatoxin M1 - 299 °C, decomposition temperature 237-306 °C
Zearalenone - 164-165 °C, decomposes
Zearalanol - 178-185 °C,
Trichothecenes:
T-2 toxin - 151-152 °C
Diacetoxyscirpenol - 162-164 °C
Neosolaniol - 171-172 °C
15-Acetyldeoxynivalenol - 138-140°C, 185°C-187 °C
3-acetyldeoxynivalenol - 185-187 °C
Deoxynivalenol - 151-153 °C, decomposes
Nivalenol - 222-223 °C, decomposes
Trichothecin - 118 °C
Fusarenon-X - 91-92°C
Roridin A - 198-204°C
Satratoxin H - 162-166 °C
Verrucarin A - 360 °C
Ochratoxin A - 168-173 °C, degrades at up to 180 °C
Ochratoxin B - 221 °C
Patulin - 110-111 °C
Cyclopiazonic acid - 245-246 °C
Sterigmatocystin - 240-246 °C
Citreoviridin - 110 °C
Citrinin - 173-175 °C, decomposes
Alternariol - 350 °C
Alternariol monomethyl ether - 267 °C
Altenuene - 190-191 °C
Altertoxin I - 180 °C
Cytochalasin A - 193-195 °C
Cytochalasin B - 215-223 °C
Cytochalasin C - 260-266 °C
Cytochalasin D - 255-260 °C
Cytochalasin E - 205-210 °C
Moniliformin - decomposes at 345-355 °C without melting
