The Research Of Analyse Polycyclic Aromatic Hydrocarbons In The Marine System With Activated Carbon Fiber-solid Phase Microextraction

With the development of economic and the exploiture of marine resources, marine pollutant is becoming an important environment problem of the world. PAHs (polycyclic aromatic hydrocarbons) in the marine environment not only affect the marine ecology but also threaten human health because of its great carcinogenicity and mutagenicity. Lots of people have attached importance to the analysis of PAHs. The marine environment system is complex and PAHs contan isomers, so it's difficult to analyse them. Recently with the development of high-sensitivity and high-selectivity analytic instrument, the detection analysis technology has had a great advancement. It is possible to make accurate analysis of PAHs. Now the pretreatment of marine samples becomes the key process of the whole analysis.Solid-phase microextraction (SPME) is a new kind of sample preparation technique. It becomes more and more popular for the analysts because of its advantage such as fast, simple, efficient, no organic solvents, easy to carry. The core part of SPME is the extraction fiber, but the currently available fibers are all manufactured by the foreign companies and less variety. They are limited by the coating temperature resistance, chemical stability and service duration. Our group studied a new type activated carbon fiber with long service duration, low production cost, stable and efficient analysis. It filled the blankness of the domestic solid-phase microextraction fiber production in a certain extent. This paper mainly makes a special modification of the ACF and then uses the modified fiber to detect PAHs in the marine environment system. This paper consists of two parts:First, make a special modification of PAHs for the ACF and increase the adsorption capacity of PAHs, improve the detection limit. The modified optimal conditions of activated carbon fibers are: the carbon fiber impregnate in the 45% phosphoric acid for 6h, then activation in the high-temperature vapor for 30min, the activation temperature is 500℃. Compared with the non-modified carbon fibers, the modified activated carbon fiber gets the peak area of PAHs ranging from [3.11*103, 4.00*106] to [2.03*105, 2.77*106] with ACF-SPME-GC method. They are increased by 4.34 times to 179.73 times. The lowest detectable limit of PAHs is decreased from [0.5μg/L, 50μg/L] to [0.01μg/L, 0.5μg/L]. The relative standard deviation percentage is decreased from [8.47, 56.32] to [1.83, 10.03]. The modification effect is great and the modified fiber could fulfil the requirement of the following analysis.Second, use the modified ACF to analyse PAHs successfully in marine water, sediment and organisms with ACF-SPME-GC method. In marine water PAHs analysis, the optimal conditions are: direct extraction for 45 min in the 60℃water bath, while stirring, salt concentration 10 % and pH 3, t desorption in 320℃for 5 min. Analyse sixteen types of PAHs under these conditions. RSD % is between 1.83 and 10.03. The lowest detectable limit is between 0.1μg and 0.5μg. Analyse the East China Sea water and find the content of these PAHs under the lowest detectable limit. Make the addition recovery experiments and the rate of recovery is between 80.81% and 128.14%. Analyse the PAHs in the marine sediment with ACF-SPME-GC method and get the optimal conditions are: add 0.50 mL acetone and 14.50 mL water into per gram sediment soil, direct extraction in 60℃water bath for 40 min and then desorption in 330℃for 5 min. Under these conditions, RSD% of these PAHs is between 1.72 and 29.23, the lowest detection limit is between 1 ng/g and 50 ng/g. Through the standard addition method of sediment samples, find five types of PAHs. Analyse the PAHs in the marine organisms with ACF-SPME-GC method and get the optimal conditions are: add 1.00 mL acetone and 14.00 mL water into per gram organisms, extract for 60 min in 60℃with direct method. Under these conditions, the RSD% of PAHs is between 3.49 and 24.11, the lowest detection limit is between 1 ng/g and 50 ng/g. Then make the sample experments and find the content of PAHs below the detection limit. Experiments show that this method of analysing PAHs is fast and efficient.