penicillic acid :
| J Assoc Off Anal Chem 1984 Nov-Dec;67(6):1108-10 |
|
Chemical confirmatory tests for ochratoxin A, citrinin,
penicillic acid, sterigmatocystin, and zearalenone performed directly on thin
layer chromatographic plates.
Golinski P, Grabarkiewicz-Szczesna J.
Published tests have been improved and a new procedure is described for chemical
confirmation of mycotoxins directly on thin layer plates. After extraction and
preliminary cleanup chromatography with n-hexane or chloroform, the mycotoxins
ochratoxin A, citrinin, penicillic acid, sterigmatocystin, and zearalenone were
easily separated by thin layer chromatography (TLC) using toluene-ethyl
acetate-90% formic acid (6 + 3 + 1) developing solvent. In chemical confirmatory
methods, the developed chromatogram was exposed to vapors of pyridine, acetic
anhydride, or a mixture, or the mycotoxins were over-spotted. With this
treatment, ochratoxin A, citrinin, penicillic acid, and zearalenone were
converted to new fluorescent compounds, and observed under 365 nm light after
re-chromatography with the same developing solvent. Sterigmatocystin was
confirmed chemically using TLC plates impregnated with 0.6N H2SO4 or 10% oxalic
acid in methanol. The described procedures are satisfactory for confirming
mycotoxins present in standards, artificially contaminated grain samples
(barley, corn, oat, rye, and wheat), and extracts from both fungal cultures and
naturally contaminated grain samples.
PMID: 6240485
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