溶胶-凝胶-硫化法制备硅橡胶吸附萃取搅拌棒

Preparation of Silicone Rubbers Coating on Stir Bar by Sol-gel-Sulfurization Method for Sorptive Extraction

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厚壁硅橡胶吸附萃取搅拌棒（ stir bar for sorptive extraction, SBSE）。采用分段硫化和多阶程序升温老化防止涂层脱落和龟裂，一次涂渍涂层厚度约150～250μm，280℃下无流失，使用寿命可达150次。利用所制备涂层，结合自制热解析系统（thermal desorption system，TDS），建立了SBSE-TDS-CGC-FID测定水样中6种多环芳烃（polyaromatic hydrocarbons，PAHs）的方法。方法的线性范围为0．3～1000μg/L，检出限为0．002～0．011μg/L，相对标准偏差在0．92％～6．14％之间。该方法能够满足欧盟2005／69／EC指令对多环芳烃低于10mg/kg的检测要求。

A novel thick silicone rubber coating stir bar（SB） was prepared for sorptive microextraction（SE）. The silicone rubber stationary phase was made by a sol-gel-sulfurization method from methyl-vinyl and vinylterminated silicone rubbers. Its thickness can reach 150 -250μm by one time dipping in the sol. The preparation conditions of the bar were optimized. Using multi-stage sulfurization and three aging steps at different temperature guaranteed no peeling and cracking to the coating. The coating can withstand desorption temperature up to 280℃. The life span of the stir bar was more than 150 times. Coupled with homemade Thermal Desolation System （TDS） and GC, a method for the analysis of 6 PAHs in water by SBSE-TDS-GC （FID） was established. The linear range of the method was 0.3 - 1.0 × 10^3μg/L, the detection limits were 0. 002 - 0.011μg/L, and the relative standard deviations（RSD） were 0.92% -6.14%. This method can meet the demand of the 2005/69/EC instruction about PAHs＇ content lower than 10mg/kg.