Radioimmunoassay of nivalenol in barley.
Antibodies against nivalenol (NIV) tetraacetate (Tetra-Ac-NIV) were prepared by immunizing rabbits with a hemisuccinate derivative of 8-hydroxy-3,4,7,15-tetraacetyl-12, 13-epoxytrichothece-9-en conjugated to bovine serum albumin. A radioimmunoassay system with one of these sera was developed to measure NIV contamination in barley. The detection limit for Tetra-Ac-NIV was about 0.5 ng/ml. The relative cross-reactivities of the antiserum with Tetra-Ac-NIV, acetyl T-2 toxin, and scirpenol triacetate, which were determined by the competitive radioimmunoassay, were 1, 0.78, and 0.56, respectively. Other derivatives showed no cross-reactivity. For the determination of NIV in a barley sample, NIV was extracted from the sample with acetonitrile-water (7:3), defatted with hexane, and then acetylated with acetic anhydride to form Tetra-Ac-NIV. The reaction mixture was loaded onto a C18 cartridge to remove excess reagents and impurities. Tetra-Ac-NIV was eluted from the cartridge with 50% methanol in water, and the eluate was subjected to radioimmunoassay. Analysis of six naturally contaminated barley samples for NIV revealed that radioimmunoassay results agreed well with gas chromatographic analyses.
Teshima
R
R
Division of Biochemistry and Immunochemistry, National Institute of Hygienic Sciences, Tokyo, Japan.
Hirai
K
K
Sato
M
M
Ikebuchi
H
H
Ichinoe
M
M
Terao
T
T
D002849:Chromatography, Gas; D002523:Edible Grain / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D005670:Fusarium / Q000302:isolation & purification; D001467:Hordeum / Q000032:analysis* / Q000382:microbiology; D009183:Mycotoxins / Q000032:analysis; D011863:Radioimmunoassay / Q000379:methods*; D012717:Sesquiterpenes / Q000032:analysis*; D014255:Trichothecenes / Q000032:analysis*
D009183:Mycotoxins; D012717:Sesquiterpenes; D014255:Trichothecenes; C038405:nivalenol