傅里叶变换红外光谱快速鉴别当归与硫磺熏蒸当归的研究

目的:利用傅里叶变换红外(FTIR)光谱法并结合二阶导数谱对当归与硫磺熏蒸当归进行快速鉴别。方法:采用傅里叶变换红外光谱法对当归与硫磺熏蒸当归的醇提物和水提物进行对比分析,并结合二阶导数进行进一步放大分析。结果:在红外光谱中非熏当归与硫熏当归的醇提物和水提物均有差异,而通过具有高分辨力的二阶导数光谱对醇提物和水提物进行分析后,区分效果更加明显。红外光谱显示,在醇提物中,硫磺熏蒸后当归吸收峰明显减少,且有新吸收峰出现;水提物中,当归与硫磺熏蒸当归在1 000～400 cm-1波长的"指纹区"变化较明显。二阶导数光谱显示,在醇提物中,硫磺熏蒸当归在约3 578,3 541 cm-1吸收峰减弱和消失,约1 400～1 200 cm-1以及800～600 cm-1两者有较明显变化;水提物中,在约3 900～3 850 cm-1以及3 800～3 750 cm-1附近两者有差异。结论:利用傅里叶变换红外光谱法结合二阶导数可以高效、简便、准确地鉴别当归与硫磺熏蒸当归,为当归药材的质量控制提供鉴别依据。

Quick identification of sun-dried and sulfur-fumigated Angelicae Sinensis Radix by Fourier transform infrared spectroscopy

Objective : To develop a quick identification method for the sun-dried and sulfur-fumigated Angelicae Sinensis Radix used by Fourier transform infrared spectroscopy (FTIR) combined with second derivative infrared spectroscopy. Method : The alcoholic and aqueous extracts of sun-dried and sulfur-fumigated Angelicae Sinensis Radix were analyzed by using FTIR, the further analysis was used by second derivative infrared spectroscopy. Result : There existed differences between their infrared spectra either extracted by ethanol or water, while the distinctions were more obvious after analyzing their alcoholic and aqueous extracts through high resolution of second derivative infrared spectroscopy. Infrared spectra showed that the absorption peaks of Angelicae Sinensis Radix were significantly reduced and a new absorption peak appeared after sulfur-fumigated process in alcoholic extracts, while both of them changed markedly in the "fingerprint region" ranging from 1 000 to 400 cm^-1 in aqueous extracts. Second derivative spectra showed that the absorption peaks of sulfur-fumigated Angelicae Sinensis Radix extracted by ethanol weakened and disappeared at about 3 578 cm^-1 and 3 541 cm^-1, while both of them differed significantly from each other ranging from 1 400 to 1 200 cm^-1 as well as 800 cm^-1 to 600 cm^-1, difference also existed between them extracted by water ranging from about 3 900 to 3 850 cm^-1 and 3 800 to 3 750 cm^-1. Conclusion : The FTIS method combined with second derivative can be utilized to distinguish sun-dried and sulfur-fumigated Angelicae Sinensis Radix efficiently, conveniently and accurately, and provide a basis for identification and quality control of Angelicae Sinensis Radix.