中文摘要：

通过优化GCMS参数有效分离了水杨酸（SA）及其羟基化产物2，3-DHBA和2，5-DHBA的硅烷化产物，检测限分别为10．2fmol和9．9fmol．采用浸渍膜捕集OH标准源发生体系产生的OH自由基，测得气相OH自由基与固相SA反应生成的2，3-DHBA和2，5-DHBA的产率分别为52％和48％．因此，SA捕集-硅烷化衍生-气质联用测量方法研究大气OH自由基有很好的应用前景．

英文摘要：

This study developed a measurement method of OH radicals in the atmosphere using salicylic acid（SA） to trap OH radicals and then GC-MS to analyze the trimethylsilyl （TMS） derivatives of the reaction products of SA and OH： dihydroxybenzonic acid（DHBA）. By optimizing GC-MS parameters, the TMS derivatives of SA and DHBAs were well separated and the detection limits of 10. 2 fmol and 9.9 fmol were obtained for the TMS derivatives of 2,3-DHBA and 2,5-DHBA. After using SA soaked filters to collect OH radicals from an OH generating sources, 2,3-DHBA and 2,5-DHBA were extracted from the filters and converted to TMS derivatives, which were measured with GC-MS and the production yields of 2,3-DHBA and 2,5-DHBA from the gas phase OH radical reaction with solid phase SA on filter were determined as 52% and 48%.