| PAHs refers to two or more benzene rings connecting to form fused ring compounds, it is a class of the cancer-causing organic pollutants, and widely present in the environment , besides it is earlier been found and studied, but also a large number of environmental carcinogens. In up to more than 1000 kinds of cancer-causing substances, PAHs accounted for 1/3 or more. With coal and oil are widely used in daily life, industrial production and transportation, PAHs generated are accumulated in the environment, so which has aroused extensive attention to adverse effects on human health, Therefore, development of rapid, reliable and sensitive technology has an extremely important to improve the environmental pollution, and ensure human health.At present, the study of PAHs mainly focus on foods, water, soil, atmosphere, etc, however, there is also no research in the medicines, therefore, the study of PAHs in chinese herbal medicines have a very important practical significance. Based on the literature, the sample pre-treatment technology is established which contains ultrasonic extraction and silica gel column purification, the technology can extract fastly Phenanthrene(Phe), Anthracene(Ant), Fluoranthene(Fu) and Benzo[a]anthracene(Chr) in chinese herbal medicines, furthermore Phe, Ant, Fu and Chr in the rhubarb are determined by gas chromatography, the results are satisfactory.The study includes four parts.1,The analysis method is established to determine Phe, Ant, Fu and Chr by gas chromatography with FID. The conditions of simultaneously to determine Phe, Ant, Fu and Chr are optimized: The speed of mobile phase(N2) is 3ml/min;Gasification temperature is 300℃;Detector temperature is 300℃;Column-box temperature use temperature-programmed;Keeping 2.5min at 180℃, then rising to 220℃at 5℃/min and keeping 6min, last rising to 240℃at 5℃/min;The speed of tail-blowing is 30ml/min;FID;Capillary column;The handing quantity is 0.2μl.2,By examining the temperature, light, time on the impact of experiment, the results shows that all of the factors are influence on the experiment. Besides it is certained how to placed stock solution and standard solution: Sealed flask containing solution should be put in refrigerator, the temperature of refrigerator is 9℃,and the storage time don,t exceed two weeks, the flask should be immediately put back into refrigerator after solution has been used.3,The length of 5cm of the silica gel column purification experiments carried out, specific operations are as follows: Plugging gently with a little cotton in nozzle of 1.5cm diameter needle, the drying silica gel powder is put into the needle, then let the entire silica gel column thoroughly wet using cyclohexane;The speed of continuous eluent is 0.125ml/min. The method is simple and reliable by proving, the effects of impurity removal is obvious, recovery can be to 92% or more.4,Phe, Ant, Fu and Chr in the rhubarb are determined by gas chromatography. At present, there has not the national standard to detect PAHs in chinese herbal medicines, in this paper, Determination of specified sixteen polycyclic aromatic hydrocarbons in aquatic products by gas chromatography-mass spectrum (SC/T 3042—2008) is selected as reference standard. The result of experiment shows that gas chromatography is rapid, sensitive, less interference, and is completely suitable for detecting Phe, Ant, Fu and Chr in the rhubarb, as well as the result fulfills every parameters of SC/T 3042—2008. |
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