为便于环保部门实时准确监测水体油污染情况, 研制了一套基于紫外荧光和物联网技术在线监测水中矿物油浓度的系统。该系统采用非对称Czemy-Turner光路的高精度单色器, 提高了分辨率;光路增加了一束参考光, 用于修正光源波动对探测结果的影响;光路增添光纤传输激发光和荧光, 减小系统因仪器振动造成的光路偏差;探头采用特殊设计光纤束, 大幅提高光纤耦合效率和信号输出;系统集成了控制模块和无线通讯模块, 实现系统的实时测量、数据处理和远程控制。该系统集成度高、探测精度高、稳定性好。利用化学计量学方法中的平行因子算法和化学校正分析理论, 降低矿物油不同成分差异带来的计算误差, 精确计算出未知样品的浓度。使用该系统测定了柴油、机油、原油三种样品溶液在10, 25, 50和100 mg·L-1的荧光光谱。用光栅光谱仪测得这三种油的最佳吸收波长分别为256, 365和397 nm;用荧光分光光度计测量了上述三种油的吸光度分别为0.028, 0.036和0.041;它们的最佳发射波长分别为355, 419和457 nm。利用该装置测得柴油、机油和原油的检出限分别为0.03, 0.04和0.06 mg·L-1, 相对误差分别为2.1%, 1.0%和2.8%。

In order to monitor the oil pollution of water real time and accurately for the environmental protection, an intelligent online detection system for the mineral oil in water is put forward in the present paper, based on the technology of ultraviolet fluorescence and internet of things (IOT). For this system, the resolution can be improved by using the higher precision asymmetric Czemy-Turner monochromator;the impact of light fluctuations on the results of exploration can be corrected by a bunch reference light;the optical system deviation caused by the instrument vibration can be reduced by optical fiber transmission;the coupling efficiency of fiber and output signal can be increased by a special fiber beam;the real-time measurement, data processing and remote control can be achieved by the control module and wireless communication module. This system has characteristics of high integration, high precision and good stability etc. The concentration of the unknown sample can be accurately calculated by the methods of parallel algorithms of chemometric metrology and the calculation errors caused by different components can be reduced by the theory of chemical correction factor analysis. The fluorescence spectra of three kinds of sample solution, diesel, engine and crude oil in preparative concentration of 10, 25, 50 and 100 mg·L-1 were measured by this system respectively. The absorption wavelengths of the above-mentioned three oils were measured to be 256, 365 and 397 nm by a grating spectrometer;their absorbances were measured to be 0.028, 0.036 and 0.041 by fluorescence spectrophotometer, respectively. Their fluorescence emission wavelengths are 355, 419 and 457 nm respectively. Finally the concentration detection limits of the mineral oil in water of diesel, engine and crude oil were obtained, i.e. 0.03, 0.04 and 0.06 mg·L-1 respectively. Their relative errors are 2.1%, 1.0% and 2.8% respectively.