Multiplex dipstick immunoassay for semi-quantitative determination of Fusarium mycotoxins in cereals.
A multiplex dipstick immunoassay based method for the simultaneous determination of major Fusarium toxins, namely zearalenone, T-2 and HT-2 toxins, deoxynivalenol and fumonisins in wheat, oats and maize has been developed. The dipstick format was based on an indirect competitive approach. Four test lines (mycotoxin-BSA conjugates) and one control line were located on the strip membrane. Labelled antibodies were freeze-dried within the microwell. Two matrix-related sample preparation protocols have been developed for wheat/oats (not containing fumonisins) and maize (containing fumonisins) respectively. The use of a methanol/water mixture for sample preparation allowed recoveries in the range 73-109% for all mycotoxins in all tested cereals, with relative standard deviation less than 10%. The optimized immunoassay was able to detect target mycotoxins at cut off levels equal to 80% of EU maximum permitted levels, i.e. 280, 400, 1400 and 3200 μg kg(-1), respectively, for zearalenone, T-2/HT-2 toxins, deoxynivalenol and fumonisins in maize, and 80, 400 and 1400 μg kg(-1), respectively, for zearalenone, T-2/HT-2 toxins and deoxynivalenol in wheat and oats. Analysis of naturally contaminated samples resulted in a good agreement between multiplex dipstick and validated confirmatory LC-MS/MS. The percentage of false positive results was less than or equal to 13%, whereas no false negative results were obtained. Data on the presence/absence of 6 mycotoxins at levels close to EU regulatory levels were obtained within 30 min. The proposed immunoassay protocol is rapid, inexpensive, easy-to-use and fit for purpose of rapid screening of mycotoxins in cereals.
National Research Council of Italy, Institute of Sciences of Food Production (ISPA-CNR), Bari, Italy. veronica.lattanzio@ispa.cnr.it
Veronica M T
VM
Lattanzio
Noan
N
Nivarlet
Vincenzo
V
Lippolis
Stefania
S
Della Gatta
Anne-Catherine
AC
Huet
Philippe
P
Delahaut
Benoit
B
Granier
Angelo
A
Visconti
D018554:Avena / Q000382:microbiology*; D002523:Edible Grain / Q000382:microbiology*; D004867:Equipment Design; D005670:Fusarium / Q000302:isolation & purification*; D007118:Immunoassay / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D009183:Mycotoxins / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D014908:Triticum / Q000382:microbiology*; D003313:Zea mays / Q000382:microbiology*
D009183:Mycotoxins