中文摘要：

建立了一种简便、灵敏、无需内标的检测油脂中三酰甘油氧化聚合物（TGP）的分析方法。以制备型快速层析柱（PFC）（flash硅胶柱,20 g,40～60μm,6 nm）分离1 g油脂样品中极性组分（PC）,经高效体积排阻色谱（HPSEC）（GPC柱,Ф7.8 mm×300 mm,粒径5μm,孔径10 nm）将PC细分为氧化三酰甘油寡聚物（TGO）、氧化三酰甘油二聚物（TGD）、氧化三酰甘油单体（ox-TGM）、二酰甘油（DG）、游离脂肪酸（FFA）。结合重量法测定油脂中PC、面积归一法测定PC中TGP,可准确定量油脂中的TGP含量。结果表明,TGO、TGD分别在28～1 800、11～2 800 mg/L范围内线性关系良好,相关系数（r2）分别为0.998 2、0.998 7,TGO及TGD的检出限（LOD）分别为28、11 mg/L,定量下限（LOQ）分别为113、44 mg/L;相当于油脂中TGP的LOD为0.01%。PFC-HPSEC法检测油脂TGP的相对标准偏差（RSD）均小于10%。PFC对3个PC加标水平（2.27%、8.47%、30.94%）的平均回收率为95%～98%,相对标准偏差（RSD）均低于4%。PFC-HPSEC方法与经典的硅胶柱-HPSEC方法定量油脂TGP的结果吻合度高,相对误差为0～8.9%。该方法能够在2 h内实现各种油脂中TGP含量的定量检测,包括使用过的废弃油脂与未使用的食用油脂,尤其适用于低含量TGP的初榨油和精炼油脂。

英文摘要：

An simple operation and high sensitivity method without internal standard was developed for the quantitative analysis of oxidized triacylglycerol polymers（TGP）.Polar compounds（PC） were obtained from 1 g oil sample by preparative flash chromatography（PFC）（flash silica column,20 g,particle size：40-60 μm,pore size：6 nm） and subsequently separated by a high-performance size-exclusion chromatography（GPC column,Φ7.8 mm×300 mm,particle size：5 μm,pore size：10 nm） into oxidized triacylglycerol polymers（TGP）,oxidized triacylglycerol dimers（TGD）,oxidized triacylglycerol monomers（ox-TGM）,diacylglycerols（DG） and free fatty acids（FFA）.By quantitation of PC in oil through gravimetric determination and TGP in PC through area normalization method,TGP content in oil was calculated.The results showed that the calibration curves for TGO and TGD were linear in the concentration ranges of 28-1 800 mg/L and 11-2800 mg/L,respectively,with correlation coefficients（r2） more than 0.99.Their LODs were 28 mg/L and 11 mg/L,respectively,and LOQs were 113 mg/L and 44 mg/L,respectively,which was equivalent to 0.01% for LOQ of TGP in oil.The RSDs of TGP in oil detected by PFC-HPSEC were less than 10%.The recoveries at spiked levels of 2.27%,8.47% and 30.94% ranged from 95% to 98% with RSDs less than 4%.In detecting TGP in oil,PFC-HPSEC matched traditional silica column well with RE of 0-8.9%.The method could be used in the determination of TGP in all kinds of oil samples,including used cooking oil and unused edible oil,especially for virgin oil and refined oils and fats with low levels of TGP.