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1 5 5 Vol. 5 No Journal of Food Safety and Quality May., 2014 李 辰 1*, 梁添旺 1, 杨伟杰 1, 许春才 2, 龚悦 2 (1., ; 2., ) 摘要 : 目的 方法 ( ), 1745 cm -1, ; 230~800 nm,, 结果, cm cm -1, ;, 668 nm 结论 关键词 : ; ; ; ; ; Preliminary identification of waste cooking oil by the infrared spectrum and ultraviolet-visible spectrum LI Chen 1*, LIANG Tian-Wang 1, YANG Wei-Jie 1, XU Chun-Cai 2, GONG Yue 2 (1. Analytical & Testing Center of Wuyi University, Jiangmen , China; 2. Foshan Institute of Quality and Technical Supervision Standards and Codes, Foshan , Guangdong Province, China) ABSTRACT: Objective To establish a simple, fast distinguish method for waste cooking oil, biodiesel and qualified cooking oils. Methods Several common cooking oils bought from supermarket, roadside restaurant oil, biodiesel and waste cooking oil (including hogwash oil and frying oil) were compared based on the relative intensity ratio of infrared (IR) spectra with a characteristic absorption peaks 1745 cm -1. Ultraviolet-visible (UV-vis) spectra ( nm) were successively used to distinguish the difference. Results The relative intensity ratio of IR spectra (absorption peaks 1745 cm -1 ) could be obviously distinguished, especially at 3473 cm -1 / 1745 cm -1, 3008 cm -1 / 1745 cm -1 and 1652 cm -1 / 1745 cm -1, and thus can be used as basis for discrimination. By comparing the starting and end wavelength of UV-vis spectra of the test oils, and whether the spectrum has higher absorbance or obvious absorption peak at 668 nm, the quality of test oil could be recognized. Conclusion The preliminary identification method can be used to quickly identify the qualified oils from waste oils. KEY WORDS: cooking oil; infrared spectrum; ultraviolet-visible spectrum; characteristic absorption peak; relative intensity; identification 基金项目 : (S ) (2010CZ14) Fund: Supported by Natural Science Foundation of Guangdong Province(S ), Project of Administration of Quality and Technology Supervision of Guangdong Province(2010CZ14), and Open Foundation of Guangdong University Engineering Research Center for Light Chemical Cleaner Production. * 通讯作者 :,, simmonlee@163.com *Corresponding author: LI Chen, Lectorate, Analytical & Testing Center of Wuyi University, No.22, Dongcheng Cun, Jiangmen , China. simmonlee@163.com

2 引言,,,,, [1-2] [3] [4] [5] [6] [7-9], [10] [11-12],,,,,,,,, [13], (infrared spectra, IR)- (ultraviolet visible spectra, UV), 2 材料与方法 2.1 材料 材料与试剂 3 (, ); (, ); (, ); (); ( ) ( ) 仪器 VERTEX 70 ( ); Helios Alpha ( Thermo Electron ); FW-4 ( ); ( ); () 2.2 实验方法 红外光谱法 KBr,, 4000~400 cm -1, 4 cm -1, 10 Scans, T%, (1) A = lg(1/t) (1) 紫外可见分光光度法,, 230~800 nm, 3 结果与讨论 3.1 红外吸收光谱 1, cm -1, : 3473 cm -1, 3008 cm -1 C-H σ C=C-H, cm -1 σ C-H, 1745 cm -1 σ C=O, 1652 cm -1 σ C=C, 1464 cm -1 C-H δ C-H, 1377 cm -1 C-H δ C-H, 1162 cm -1 C O σ C-O, 722 cm -1 (CH 2 ) n (n 4) γ C-H, 3,, 1745 cm -1,

3 5, : (1) A, 1745 cm -1,, 1 1 Fig. 1 Infrared (IR) spectra of the qualified edible oil and the waste oils (1. ; 2. ; 3. ; 4. ; 5. ; 6. ; 7. ) (1. peanut oil; 2. blend oil; 3. corn oil; 4. hogwash oil; 5. frying oil; 6. roadside restaurant oil; 7.biodiesel) 1, cm -1 ( ), C H 3008 cm -1,, cm -1 C H, cm -1,, 3473 cm -1, 3 ( ), 1, 1652 cm -1,, [7] (U/R=1.9) (U/R=4.4) 1162 cm -1 Table 1 * 表 1 红外吸收光谱特征吸收峰的相对强度 Relative intensities of the characteristic absorption peaks in infrared spectra A 3473 / A 3008 / A 2925 / A 2854 / A 1652 / A 1464 / A 1377 / A 1162 / A 722 / (0.0020) (0.0190) (0.0285) (0.0228) (0.0032) (0.0185) (0.0171) (0.0158) (0.0117) (0.0019) (0.0204) (0.0259) (0.0310) (0.0035) (0.0195) (0.0158) (0.0128) (0.0126) (0.0024) (0.0147) (0.0196) (0.0214) (0.0028) (0.0159) (0.0162) (0.0174) (0.0131) (0.0028) (0.0092) (0.0245)) (0.0158) (0.0015) (0.0147) (0.0121) (0.0126) (0.0095) (0.0031) (0.0106) (0.0314) (0.0254) (0.0021) (0.0092) (0.0126) (0.0157) (0.0124) (0.0017) (0.0124) (0.0274) (0.0247) (0.0028) (0.0112)) (0.0211) (0.0264) (0.0087) (0.0024) (0.0106) (0.0185) (0.0156) (0.0018) (0.0145) (0.0124) (0.0198) (0.0056) : * 3, SD

4 C O,,,, ( cm cm -1, : A 3473 cm -1/ cm -1>0.10, A 3008 cm -1/ cm -1<0.65, A 1652cm -1/ cm -1 < 0.13,,, 3.2 紫外可见吸收光谱 230 nm,,, 230 nm, 230~800 nm, 2 (350~700 nm), nm,, 400 nm, 550 nm, 360~550 nm,, ( 2 400~500 nm), 400 nm, 450 nm, ( ) 700 nm, 800 nm, nm 3, [3],,, 3, 668 nm , 0.037,, 0.002~0.012, 668 nm 0.025, 668 nm,, [3] Fig. 2 2 Ultraviolet-visible (UV) spectra of the qualified oils and the waste cooking oils

5 5, : 1375, 668 nm,,,,,,, 400 nm, 400 nm 668 nm ( 0.025),, 668 nm,, 668 nm 0.025, nm 3, 4 结论 4000~400 cm -1, A 3473 cm -1/ cm -1 > 0.10, A 3008 cm -1/ cm -1 < 0.65, A 1652cm -1/ cm -1 < 0.13,, (> 400 nm) ( 360 nm), 668 nm (> 0.025), 668 nm,,, ( [5] [7] [14] [15] ),,, 参考文献 [1],,,. [J]., 2012, 28(6): Xu HY, Cheng L, Wang DF, et al. Identification of recycled cooking oil by FT-IR[J]. Mod Food Sci Technol, 2012, 28(6): [2],,,. - [J]., 2013, 38(1): Xu HY, Cheng Lian, Wang Dongfeng, et al. Discerning of swill-cooked dirty oil by FTIR with heating headspace [J]. China Oil Fat, 2013, 38(1): [3],,,. [J]., 2006, 25(3): Wang Y, Yin PH, Liang FH, et al. Distinguishing hogwash oil from peanut oil by ultraviolet-visible spectrophotometry [J]. Chin J Anal Lab, 2006, 25(3): [4],,. [J]., 2010, 6: Zhang HJ, Wang HB, Tang Y. Determination of trace sodium dodecyl benzence sulfonate in hogwash oil by synchronous fluorescence quenching spectrometry[j]. Anal Instrum, 2010, 6: [5],,,. [J]., 2007, 14(3): Peng J, Huang DP, Liu JX, et al. Application study of electrical conductivity measurement in hogwash oil identification [J]. Pract Prev Med, 2007, 14(3): [6],,,. [J]., 2004, 29(4): Yin PH, Pan JY, Zhao L, et al. Quick discrimination of ageing frying oil and hogwash oil from good edible vegetable oil with thin layer chromatography [J]. China Oil Fat, 2004, 29(4): [7],. GC-MS [J]., 2011, 36(4): Li XY, Peng DW. Quality analysis of cooking waste oil and edible vegetable oil by GC-MS [J]. China Oil Fat, 2011, 36(4): [8],,,. GC-MS [J]., 2010, 31(5A): Li H, Tu DW, Li GR, et al. SPME and principal component analysis of hogwash oil GC-MS fingerprint [J]. Acta Metrol Sinica, 2010, 31(5A): [9],,,. - - [J]., 2010, 29(6): Li H, Tu DW, Li GR, et al. Identification of hogwash oil by HP-SPME/GC-MS [J]. Chin J Anal Lab, 2010, 29(6): [10],,,.

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