热熔型反光道路标线涂料的红外光谱三级鉴定

Tri-Level Infrared Spectroscopic Identification of Hot Melting Reflective Road Marking Paint

为了能从交通事故现场的微量物证中检测出道路标线涂料,并进一步区分其厂牌,选取国内三个不同厂牌的热熔型反光道路标线涂料及其配方原料,利用一维红外光谱(FTIR)、二阶导数光谱(SD-IR)、二维相关光谱(2D-IR)进行三级鉴定研究。实验结果表明,三个厂牌的涂料在一维谱图上峰形相似度很高,只是吸收峰波数有一定的差异,在1 435cm^(-1)附近都有宽强吸收峰,879,2 955,2 919,2 870cm^(-1)附近也有较强吸收峰,经过分区域局部放大并与每种配方原料图谱比对分析,可将三个厂牌涂料加以区分,700~970和1 370~1 660cm^(-1)区域内主要反映出三厂牌涂料的重质碳酸钙相对含量不同,2 800~2 960cm^(-1)区域内主要反映出聚乙烯蜡(PE蜡)、乙烯醋酸乙烯树脂(EVA)、邻苯二甲酸二辛酯(DOP)的相对含量不同。二阶导数谱图不仅验证了一维光谱分析的结果,而且进一步扩大微观差异,并在512~799cm^(-1)区域内反映出石英砂相对含量的不同。在1 351~1 525cm^(-1)范围内的二维红外相关光谱中,自动峰出现的位置和个数有着更为显著的差异。因此,红外光谱三级鉴定是一种快速有效识别、区分热熔型反光道路标线漆的方法,并且表观分辨率逐级提高。

In order to detect the road marking paint from the trace evidence in traffic accident scene,and to differentiate their brands,we use Tri-level infrared spectroscopic identification,which employs the Fourier transform infrared spectroscopy（FTIR）,the second derivative infrared spectroscopy（SD-IR）,two-dimensional correlation infrared spectroscopy（2D-IR）to identify three different domestic brands of hot melting reflective road marking paints and their raw materials in formula we Selected.The experimental results show that three labels coatings in ATR and FTIR spectrograms are very similar in shape,only have different absorption peak wave numbers,they have wide and strong absorption peaks near 1 435cm^-1,and strong absorption peak near 879,2 955,2 919,2 870cm^-1.After enlarging the partial areas of spectrograms and comparing them with each kind of raw material of formula spectrograms,we can distinguish them.In the region 700-970and 1 370-1 660cm^-1 the spectrograms mainly reflect the different relative content of heavy calcium carbonate of three brands of the paints,and that of polyethylene wax（PE wax）,ethylene vinyl acetate resin（EVA）,dioctyl phthalate（DOP）in the region 2 800-2 960cm^-1.The SD-IR not only verify the result of the FTIR analysis,but also further expand the microcosmic differences and reflect the different relative content of quartz sand in the 512-799cm^-1 region.Within the scope of the 1 351 to 1 525cm^-1,2D-IR have more significant differences in positions and numbers of automatically peaks.Therefore,the Tri-level infrared spectroscopic identification is a fast and effective method to distinguish the hot melting road marking paints with a gradually improvement in apparent resolution.