拉曼光谱检测PVC塑料中邻苯二甲酸二乙基己基酯的方法优化

为了提高拉曼光谱快速定量检测PVC塑料中邻苯二甲酸二乙基己基酯(DEHP)塑化剂的准确性和可靠性,研究了样品厚度、激光波长、激光功率、测试时间、降噪方式、光漂白时间及信号叠加次数等实验条件对PVC基体中DEHP拉曼光谱信号强度的影响规律.获得了拉曼光谱最佳的测试参数,包括:样品的厚度不小于5 mm;入射激光波长785 ...

Study on optimization of Raman spectroscopy for the detection of diethylhexyl phthalate in PVC plastic

In order to improve the accuracy and reliability of rapid and quantitative detection of diethylhexyl phthalate (DEHP) in plastics by Raman spectroscopy, the effects of experimental conditions (including sample thickness, laser wavelength, laser power, testing time, noise reduction method, photobleaching time and the number of signal superposition) on the Raman signal intensity of DEHP in PVC matrix were studied. The optimum parameters of Raman spectrum were obtained as follows: the thickness of sample was not less than 5 mm; the wavelength of incident laser was 785 nm; the laser power was not less than 300 mW; the testing time was not less than 2 s; the Raman spectrum of real-time background acquisition was used to reduce the background noise; the photobleaching time was more than 15 s; the number of signal superposition was 10. The limit of detection for DEHP was 0.13%. The mass fraction of DEHP in PVC matrix was significantly reduced from the spectral information reflected in the optimized conditions, which provided a rapid and quantitative analysis method for the detection of low content DEHP by Raman spectroscopy.