表面增强拉曼光谱(SERS)快速检测食用油中的苯并[a]芘

Study on Rapid Quantification of Benzo[a]pyrene in Edible Oil by Surface Enhanced Raman Spectroscopy

苯并(a)芘广泛存在于煤焦油、炼油等工业污水中,多次使用的高温植物油、烧焦的食物都可能含有苯并(a)芘。我国目前对食用植物油类产品中苯并(a)芘的限量标准是<10μg/kg。检测食品中苯并(a)芘的方法中使用较多的是高效液相色谱法、气相色谱-质谱联用法等方法,但检测过程样品的前处理复杂、检测耗时长、检测效率低,尚不能满足实时、现场检测的要求。本文使用纳米金修饰的多孔材料作为SERS基底,利用SERS对食用油中的苯并(a)芘的含量进行快速检测。苯并(a)芘在0~200μg/L范围内与SERS的信号值呈线性关系,线性方程为y=134.98x-571.77,R2=0.9942;在10μg/kg含量水平下,样品回收率为93.2~125.7%,相对标准偏差为10~18%,方法检出限为5.6μg/L。SERS可使用便携式拉曼光谱仪进行现场检测,测试时间短(一般为数十秒至一两分钟)。在检测灵敏度满足要求的情况下,SERS方法为快速筛查食用油中苯并(a)芘含量提供了一种新的选择。

Benzo[a]pyrene （BaP） is widespread in the industrial sewage from coal tar and oil refining; vegetable oil subjected multiple times to a high temperature as well as charred food may also contain BaP. The permissible limit of BaP in China for edible vegetable oil products is below 10 μg/kg. At present, the most widely used methods for quantification of BaP in food are high performance liquid chromatography, gas chromatography with mass spectrometry, and some others. Nonetheless, in the above methods, sample pretreatment is complicated, measurement time is long, and measurement efficiency is low; therefore, they still cannot meet the requirements for real-time and in situ analysis. Rapid quantification of BaP in edible oil by surface enhanced Rarnan spectroscopy （SERS） was studied here by means of nanogold-m0dified porous materials as a SERS substrate. A linear relation between the peak area of SERS and the concentration of BaP was obtained in the range of 0--200μg/L. The linear equation wasy= 134.98x-571.77 （R^2=0.9942）. At a concentration of 10 μg/kg, the recovery rates of samples ranged from 93.2% to 125.7%, and the relative standard deviations （RSDs） were between 10% and 18%. The detection limit of the SERS method was 5.6 μg/L. The analysis of BaP by the SERS method could be carried out on site using a portable Raman spectrometer, and measurement time was short （generally tens of seconds to one or two minutes）. The SERS method provides a new option for rapid quantification of BaP in edible oils if the analytical sensitivity meets the requirements.