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采用溶胶-凝胶-硫化法,以甲基乙烯基硅橡胶和乙烯基封端硅橡胶为原料,制备了6种规格的搅拌棒,分别为2 cm(涂层3 mg、8 mg、13 mg)和1 cm、2 cm、3 cm(涂层皆8 mg)。以多环芳烃为目标分析物,考察了搅拌棒的萃取效率。结果表明,萃取条件不变,分子量小的多环芳烃,增加涂层厚度或体积,可提高萃取效率。分子量大的多环芳烃,要提高萃取效率,除具备一定的萃取体积,还要有足够的表面积。用长度1 cm(涂层3 mg、6 mg)、长度2 cm(涂层3 mg)、长度3 cm(涂层6 mg、13 mg)的搅拌棒,优化条件下,萃取5 min~30 min时,多环芳烃的检出限2 ng/L~140 ng/L,各组分峰面积的相对标准偏差小于12%。实际样品雨水的分析,发现了萘及苊的存在。
Six kinds of stir bars were prepared by sol-gel-vulcanization method using methyl vinyl silicone rubber and vinyl-terminated silicone rubber as raw materials, respectively, with 2 cm coating thickness of 3 mg, 8 mg and 13 mg ) And 1 cm, 2 cm, 3 cm (8 mg each). Polycyclic aromatic hydrocarbons as the target analyte, investigated the stirring rod extraction efficiency. The results show that extraction conditions remain unchanged, small molecular weight polycyclic aromatic hydrocarbons, increasing the thickness or volume of the coating can improve the extraction efficiency. Polycyclic aromatic hydrocarbons with large molecular weight, to improve the extraction efficiency, in addition to have a certain extraction volume, but also have enough surface area. Using a stirring rod with a length of 1 cm (coating 3 mg, 6 mg), length 2 cm (coating 3 mg) and length 3 cm (coating 6 mg, 13 mg) under optimized conditions for 5 min to 30 min , The detection limit of PAHs was between 2 ng / L and 140 ng / L, and the relative standard deviation (RSD) of peak area of each component was less than 12%. The actual sample rainwater analysis found the presence of naphthalene and croton.