SCREENING FOR TOTAL ERGOT ALKALOIDS IN RYE FLOUR BY PLANAR SOLID PHASE EXTRACTION COUPLED TO FLUORESCENCE DETECTION AND MASS SPECTROMETRY


Claudia Oellig, Tina Melde
Organization(s): University of Hohenheim, Germany

Ergot alkaloids are commonly produced by the ergot fungus Claviceps purpurea and are responsible for poisonings and toxicological effects in mammals. The parasitic fun-gus is mainly growing on rye, and the infestation with Secale cornutum, the permanent form of Claviceps purpurea, is a serious problem. Despite the known toxicity and the infestation of rye grain and flours with Secale cornutum, there are no maximum limits established for ergot alkaloids in grain and grain-based food in Europe. Nevertheless, the European Union strongly recommends the monitoring of ergot alkaloids in food and feed.

Since for monitoring the quantity of individual ergot alkaloids is not relevant, the deter-mination of ergot alkaloids as the sum is a meaningful and efficient new approach.

Therefore, a fast screening method for the determination of the total ergot alkaloids in rye by planar solid phase extraction (pSPE) was developed. After a single methanol development on high-performance thin-layer chromatography (HPTLC) amino plates, ergot alkaloids are detected as the sum, according to the pSPE concept. For quantita-tion, the native fluorescence was scanned at UV 254/>400 nm. Method performance parameters were highly satisfactory with LOD and LOQ of 0.07 and 0.24 mg/kg rye, re-spectively, expressed as ergocristine, and near-100% recoveries for Secale cornutum spiked rye flours at spiking levels around 1000 µg/kg. The fast pSPE–FLD is an effi-cient alternative to the time-consuming HPLC determination of individual alkaloids and calculating the sum of them. HPTLC–MS offers the identification and determination of the ergot alkaloid composition in a single mass spectrum.

Dr. Claudia Oellig

Claudia Oellig is scientific assistant at the Department of Food Chemistry, University of Hohenheim (Germany). At the Department, she is responsible for practical training and teaching and performs research activities in the field of additives, pesticide residues and contaminants in food and feed. Her research is focused on the development of analytical methods, mainly screening methods, aiming at simple and fast separation and detection techniques and at the development of alternative sample clean-up techniques for a higher reliability and sensitivity.

Claudia Oellig obtained the degree as a food chemist (diploma) in 2008; her diploma thesis addressed the separation of food dyes with HPTLC and ultra-thin layers in the field of Planar Chromatography. She pursued her work in this field and earned the PhD degree in 2014 for her method development in pesticide residue analysis under the heading "High-throughput planar solid phase extraction – a new clean-up concept in multi-residue analysis of pesticides".

She is author and co-author of seven peer-reviewed publications, twelve invited papers and one book chapter. Her research was presented in more than 30 contributions (oral and posters) at national and international conferences (2009 - 2016).