The neutral bio - oi1 can be separated into three fractions : the fraction washed down by cyclohexane ( c1 ) mainly contains aromatics with up to four rings ; the fraction washed down by benzene ( c2 ) mainly contains alkyl - substituted aromatic hydrocarbons and polyphenols ; and the fraction washed down by methanol ( c3 ) mainly contains ester polar components 中性油层析分离为3个馏分：环己烷洗脱馏分( c1 )主要为四环以下纯缩合化合物；苯洗脱馏分( c2 )主要由单环烷基芳烃和多酚组成；甲醇洗脱馏分( c3 )主要是酯类极性化合物。
