Polycyclic aromatic hydrocarbon (PAHs) are widely found in the natural environment of human life such as the atmosphere, water, soil, crops and food. As of April 2013 known about more than 200 kinds of polycyclic aromatic hydrocarbon. PAHs in the atmosphere exist in the form of gas and solid, and the PAHs with small molecular weight are mainly in the form of gaseous form. The distribution of PAHs in the gaseous and granular states is basically the same, and the 5h7 high molecular weight PAHs The vast majority of them exist in particulate form. The polycyclic aromatic hydrocarbon in the water can be in three states: adsorbed on the suspended solids; dissolved in water; emulsified state. There are more than 20 kinds of polycyclic aromatic hydrocarbon in known surface water. Groundwater and seawater are also detected in PAHs. The concentration of PAHs in the soil is generally in the range of 10-10μg / Kg, and the concentration of PAHs in the suburban soil is higher, reaching 10-10μg / Kg. Soil pollution must affect the growth of crops. Vegetable in the content of BPa leaves the most vegetables, vegetables and vegetables, followed by vegetables and vegetables
With the continuous progress of science and technology, polycyclic aromatic hydrocarbon detection methods are constantly evolving from the beginning of column adsorption chromatography, paper chromatography, thin layer chromatography (TLC) and gel permeation chromatography (GPC) to today's gas phase (UV) and emission spectra (including fluorescence, phosphorescence and low temperature luminescence), as well as mass spectrometry, nuclear magnetic resonance and infrared spectroscopy (HPLC), reverse phase high performance liquid chromatography (RP-HPLC) , As well as a variety of analytical methods between the joint technology. More commonly used spectrophotometry and reverse phase high performance liquid chromatography. In recent years, the method of polycyclic aromatic hydrocarbon has been developing rapidly, and a variety of new analytical techniques such as microwave assisted solvent extraction, solid phase microextraction and supercritical fluid have emerged.
Spectrophotometric methods are ultraviolet spectrophotometry, fluorescence spectroscopy, phosphorescence, low temperature emission spectroscopy and some new luminescence analysis and so on. Analysis of RAHs polycyclic aromatic hydrocarbon (PAHs) by luminescence technique has the advantages of high sensitivity and strong specificity in absorption spectrophotometry. The sensitivity of the luminescence method is 10-100 times higher than that of the absorption method, and the detection amount is about 10.6 to 10.8 g. As the UV spectrophotometry instrument is simple, versatile, it is also more common. The apparent absorbance (ε) of PAHs is about 10-10, and the detection sensitivity is about the order of μg.