乙酸乙酯抽提法在ESR检测一氧化氮自由基中的应用

改进了用有机溶剂抽提检测一氧化氮(nitric oxide，NO)自由基的方法，并利用有机溶剂抽提法检测了小鼠心肌中NO的含量.有机溶剂可以把二乙基二硫代氨基甲酸钠(diethyldithiocarbamate, DETC)捕集NO的产物(DETC)₂-Fe²⁺-NO由水相中萃取并富集到酯相中，然后利用电子顺磁共振波谱仪(ESR)在常温下检测大体积样品中的NO.比较了几种不同的有机溶剂：正丁醇、乙酸丁酯、乙酸乙酯、三乙酸甘油酯、乙酸异戊酯等的萃取能力，发现乙酸乙酯是一种理想的提取溶剂.乙酸乙酯提取法可以使NO的量与ESR信号强度在20 μmol/L内有良好的线性，使ESR的检测灵敏度提高到200 nmol/L以下；(DETC)₂-Fe²⁺-NO对光比较敏感，见光易于分解；复合物在乙酸乙酯中避光保存于4℃可稳定十几天而无显著的变化.

Application of Ethyl Acetate Extraction in Detecting Nitric Oxide by ESR

The extraction method with organic solvent extraction to detect nitric oxide was improved, and the production of nitric oxide in mice myocardium in vitro was detected with this method. Using organic solvent (DETC)2-Fe2 + -NO complex was extracted from water phase into ester phase, and nitric oxide in sample of large volume can be detected by ESR at room temperature. The extracting ability of several organic solvents such as ethyl acetate, butyl acetate, glycerol triacetate, iso-amy lacetate, and n-butanol, was compared, and it was found that ethyl acetate was a good kind of organic solvent. There was a good linear relationship between the concentration of nitric oxide and ESR intensity within concentration of 20μmol/L, and the detected limit was improved to below 200 nmol/L; (DETC)2-Fe2+ -NO complex is easy to decompose in light but it is very stable in dark at 0～4℃ which, there is only a little change after ten days.