非完全汽化法测定棕榈油中微量甲苯、二甲苯

GC DETERMINATION OF TRACE AMOUNTS OF TOLUENE AND XYLENE IN PALM OIL BY INCOMPLETE VAPORIZATION

采用正己烷稀释棕榈油样品 ,在相对较低的汽化温度下直接色谱进样 ,其中棕榈油不汽化留在汽化室的填充石英棉上 ,而甲苯和二甲苯汽化后进入毛细管柱进行FID检测 ,并与顶空气相色谱法进行了比较。该法的精密度比顶空法好 ,对于测定较高沸点的残留苯系物 ,检出限也更低。

The palm oil sample was diluted with n-hexane and introduced directly into the gas chromatograph at the low vaporization temperature of 260℃. Toluene and xylene were vaporized and determined by GC with FID detector, whereas the palm oil was detained on the silica wool in the injector. The results were found to have better precision as compared with those obtained by head-space GC. In addition, lower detection limit were obtained in the determination of residual benzene homologues with high boiling points.