为了探讨石油醚是否有荧光及其在橄榄油中残留的荧光检测可行性,采用荧光分析法实验研究了石油醚及其不同含量下橄榄油溶液的荧光特性。结果表明,石油醚存在320 nm~380 nm紫外区和380 nm~520 nm紫绿区的荧光; 在240 nm~300 nm的光激发下,两谱区都随激发波长增加而增强,但第一区更强; 在305 nm激发时,第一区开始减弱,当激发波长大于320 nm后,紫外区很快减弱直至消失,第二区继续增强,激发波长增到360 nm时,第二区最强,大于360 nm时,荧光减弱; 而少量石油醚的加入可增强橄榄油的特征荧光峰,甚至出现约405 nm的红移了的石油醚特征荧光峰,由此可对橄榄油中的石油醚残留进行检测; 当激发波长分别为320 nm、340 nm和360 nm时,橄榄油中的石油醚的体积分数检测限分别可达到大约0.059、0.048和0.043。该工作将石油醚的研究拓展到了荧光及橄榄油中石油醚残留的荧光检测领域。

To explore whether petroleum ether (PE) emits fluorescence or not and whether its residual in olive oil (OL) can be detected by fluorescence method or not, the fluorescence characteristics of PE and its composition with OL at different proportions were experimentally investigated by adopting fluorometry. The results show that PE exists fluorescence which consists of UV spectral region 320 nm~380 nm and purple-green spectral region 380 nm~520 nm. At the excitation region 240 nm~300 nm, the intensity of the two spectra increases with increase of excitation wavelength, but the first spectral region is stronger. At the excitation wavelength of 305 nm, the first spectral region begins to weaken. When the excitation wavelength is larger than 320 nm, the UV spectral region weakens and disappears quickly, while the second region continues to increase with increase of excitation wavelength. When the excitation wavelength increases to 360 nm, the second spectrum becomes the strongest. When the excitation wavelength is larger than 360 nm, the fluorescence weakens. Addition of small amount of PE into OL can enhance the OL characteristic peaks and even lead to appearance of the red-shifted characteristic peak 405 nm of PE, which can be utilized to detect PE residual in OL. The volume fraction limit of detection of PE in OL can reach 0.059, 0.048, and 0.043 for the excitation wavelength 320 nm, 340 nm, and 360 nm, respectively. This work expands the research of PE to fluorescence and fluorescence detection of PE residual in OL.