八角茴香与其伪品莽草的红外光谱三级鉴定研究

Study on the Identification of Illicium Vatum Hook. f. and Illicium Lanceolatum A. C. Smith by Multi-Ateps Infrared Macro-Fingerprint Method

采用红外光谱三级鉴定的方法区分和鉴别了八角茴香及其伪品莽草。红外光谱三级鉴定即依次采用一维红外光谱、二阶导数谱和二维相关红外光谱,分辨率逐渐提高,谱图的差别也进一步放大。一维谱图中,两者整体峰形比较相似,但在3400 cm^-1附近八角茴香只出现一个特征峰3392 cm^-1,而莽草则出现3482和3387 cm^-1两个特征峰。二阶导数谱在850-1180 cm^-1波段八角茴香的几个强峰峰强相对比较接近,其中1015 cm^-1为图中最强峰,而莽草的最强峰在1070 cm^-1附近;在1180-1500 cm^-1波段八角茴香在1469,1454,1442 cm^-1附近的3个特征峰峰强明显强于1292,1276,1 266 cm^-1附近的特征峰,而莽草则刚好相反。二维相关红外光谱中差异更明显,850-1165 cm^-1波段八角茴香在主对角线上的自动峰较强峰出现在1153和1000 cm^-1,而莽草峰强较强的自动峰出现在911和878 cm^-1;1165-1500 cm^-1波段八角茴香呈现2个自动峰,而莽草则出现5个自动峰。可见红外三级鉴定方法是一种快速有效的鉴定中药材的方法。

Illicium vatum Hook.f.and its counterfeit Illicium lanceolatum A.C.Smith can be discriminated and identified by using multi-steps infrared maro-fingerprint method.The method combines three steps： general infrared spectroscopy（FTIR）,secondary derivative spectroscopy and two dimensional correlation infrared spectroscopy（2D-IR）.The resolution is getting higher and higher and the differences of spectra are magnified farther.The holistic shape of peaks is similar in the FTIR spectra of Illicium vatum Hook. f.and Illicium lanceolatum A.C.Smith,but the spectra of llicium vatum Hook.f.show only one characteristic peak at 3 392 cm^-1,while the spectra of Illicium lanceolatum A.C.Smith show two characteristic peaks at 3 482 and 3 387 cm^-1,respectively.Observing their secondary derivative spectra,in the range of 850-1 180 cm^-1 the strongest peak of llicium vatum Hook.f.is at 1 015 cm^-1 and the intensity of other strong peaks is similar.However,the strongest peak of Illicium lanceolatum A.C.Smith is at 1 070 cm- 1.In 1 180-1 500 cm^-1,the intensity of peaks at 1 469,1 454 and 1 442 cm^-1 of llicium vatum Hook.f.is stronger than that of peaks at 1 292,1 276,1 266 cm- 1.The status of Illicium lanceolatum A.C.Smith is just opposite.The distinction of 2D-IR correlation spectra is more obvious.In 1 165-1 500 cm^-1,the stronger automatic peaks of llicium vatum Hook.f.present at 1 153 and 1 000 cm^-1,respectively,but those of Illicium lanceolatum A.C.Smith present at 911 and 878 cm1,respectively.In 1 165-1 500 cm^-1,llicium vatum Hook.f.has two automatic peaks while Illicium lanceolatum A.C.Smith has five automatic peaks.The multi-steps IR macro-fingerprint method is rapid and effective.