Method Abstract for Post-column Liquid Chromatography 203

Multi-Residue Mycotoxin Analysis
Single Run Analysis of Deoxynivalenol , Aflatoxins, Ochratoxin A, Zearalenone and Fumonisin by HPLC and Post-column Derivatization

Here you can download this material in PDF format^*

MARIA OFITSEROVA, PHD

DARSA SIANTAR, PHD*

SAREETA NERKAR, PHD

MICHAEL PICKERING, PHD

Although Aspergillus (Aflatoxins, Ochratoxin A) are generally associated with peanuts and Fusarium (Deoxynivalenol , Zearalenone) with wheat, these fungi and those that produce other toxins are not host selective and so can cross plant species. This situation is complicated by the fact that the microscopic mold may not be visible to the naked eye. Also, when infected grains are processed, any visible mold is lost but the toxic metabolites carry over into the finished products. Thus, multiresidue analytical screens for toxins in grain and finished goods are a wiser choice than single-family protocols. We present here two such screens that cover five families of toxins.

Method One:  Analysis of Deoxynivalenol , Aflatoxins, Ochratoxin A and Zearalenone in single run

Method Two:  Analysis of Deoxynivalenol, Aflatoxins and Fumonisins in single run

Sample Preparation (Method One)

A 5 mL portion of the beverage or extract is loaded into an antibody-based cartridge. The cartridges used were “Afla/DON/Ochra/Zear” in the first method and “Afla/DON/Fumo” in the second method. The cartridge is washed with 1 mL of water. The mixed toxins are eluted with 3 mL of Methanol. The Methanol solution is evaporated to dryness and is reconstituted in 250 mL of Methanol.

Sample Preparation (Method Two)

Repeat above method with Afla/DON/Fumo antibody cartridge.

Analytical Conditions (One & Two) COLUMN: MYCOTOX™ reversed-phase C18, high resolution/capacity 4.6 x 250 mm Catalog No. 1612124 TEMPERATURE: 40 °C FLOW RATE: 1.0 mL/min MOBILE PHASE: - D.I. Water - Acetonitrile - Methanol - Phosphate buffer (pH 3.3): MeOH (90:10)

Post-column Conditions (Method One) POST-COLUMN SYSTEMS: Pinnacle PCX TEMPERATURE: 90° C REAGENT: 12, 100 mg/Lt. DETECTION: - DON   DAD 218 nm - Aflatoxins   Fluorescence ex: 365 nm; em: 455 nm - Orchratoxin A   Fluorescence ex: 335 nm; em: 455 nm - Zearalenone   Fluorescence ex: 275 nm; em: 455 nm

ACKNOWLEDGEMENT:

* Darsa Siantar, Ph.D. – Bureau of Alcohol, Tobacco & Firearms, Department of the Treasury.

We wish to thank VICAM in Watertown, MA and PROMEC of MRC in South Africa for materials and assistance.

* Please use Acrobat Reader to open this file