Quantitation of 1,4-Benzoxazin-3-ones in Maize by Gas-Liquid Chromatography

Abstract

GLC procedure is reported for the quantitation of the trimethylsilyl (TMS) derivatives of substituted 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one (2-hydroxy-2H-1,4-benzoxazin-3(4H)-one[HBOA]; 2-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one [HMBOA];2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one[DIBOA];2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one[DIMBOA]; and 2,4-dihydroxy-7,8-dimethoxy-2H-1,4-benzoxazin-3(4H)-one[DIM2BOA]) found in maize (Zea mays L.) extracts. Derivatized samples were chromatographed on columns with liquid phases of 2% DC-11 and 3% OV-17 and detected by flame ionization. Internal standards were methyl palmitate and methyl stearate on DC-11 and methyl behenate on OV-17. Detector response was linear to at least 5 nmol for TMS2-HBOA and TMS2-DIBOA and to 19 nmol for TMS2-DIMBOA. Standard errors of 2% or less were obtained when 4 replicate samples were analyzed. For each maize line examined, the amount of DIMBOA determined by GLC was directly proportional to the amount of ferric chloride-reactive material determined colorimetrically.