邻苯二甲酸二丁酯中红外吸收光谱的理论分析及检测

邻苯二甲酸二丁酯(DBP)为邻苯二甲酸酯类(PAEs)，是一种常用的塑化剂。DBP极易转移进入大气、水体、土壤和食品中，对环境与人体健康造成伤害。应用第一性原理，采用密度泛函理论(DFT) B3LYP方法，在6-31G*基组水平上对DBP分子基态的平衡几何构型和能量进行优化，利用Gaussesview 5.0软件得到了DBP的红外(infrared, IR)振动光谱。与实验得到的DBP溶液的傅里叶变换红外光谱相比较，在400～4 000 cm-1波段范围内，理论模拟与实际测得的红外光谱的特征吸收峰基本保持一致，且实验测得的基团振动位置也可与红外理论基团特征峰位置相对应。考虑到实验条件以及温度等因素的影响，理论光谱与实验光谱吻合得较好。通过对实验光谱相对于理论光谱对应峰值的线性拟合发现，其相关度≥99%。这为DBP的检测与分析提供了一定的理论依据。

Dibutyl Phthalate Theoretical Analysis and Detection in Infrared

Di-n-butyl phthalate (DBP) is one kind of Phthalate esters (PEs) widely employed as plasticizers in the production of polymeric materials. PEs are dialkyl and alkyl aryl esters of 1,2-Benzenedi-carboxylic acid, which comprise a wide group of compounds. Since these compounds are not linked to the polymeric matrix, they can migrate from their original containers to the surrounding environment, resulting in ubiquitous environmental pollutants. The infrared vibration spectra of isolated DBP was assigned according to DFT calculations by Gaussesview 5.0 software with First Principles. The method of B3LYP of the density functional theory (DFT) at 6-31G* level has been used to calculate its geometrical parameters and convergence criteria. Compared with the Fourier transform infrared spectrum of DBP in 400~4 000 cm-1 band, the characteristic absorption peaks of the simulation spectrum were broadly in agreement, and the position of the peaks were almost corresponding to each other. Considering the influence of the experimental conditions and temperature, theoretical calculations were in good agreement with experimental data. According to the linear fitting of the peak position of the experimental spectra with respect to the theoretical spectra, the correlation degree is more than 99%. This research provides a theoretical basis to the detection and analysis of DBP.