【摘要】 建立了用硫酸甲醇甲酯化衍生-固相萃取富集/气相色谱测定烟草中9种有机酸的方法,首次实现了强酸介质中有机酸酯的固相萃取。烟草样品用硫酸-甲醇进行甲酯化衍生,衍生生成的有机酸酯用MCIGEL反相树脂分离富集,萃取液用甲醇洗脱后进行气相色谱分析,采用DB-5毛细管色谱柱,进样量1.0μL,不分流进样;检测器温度250℃。方法可同时准确测定烟草样品中乳酸、草酸、丙二酸、乙酰丙酸、苹果酸、柠檬酸、棕榈酸、硬脂酸、亚油酸的含量,各有机酸的加标回收率为92.2%~102.6%,相对标准偏差为2.4%~3.2%,定量下限为0.20~0.36 mg/L。该方法准确、灵敏度高,能够满足实际样品的测定要求。更多还原

【Abstract】 A new method for the determination of 9 organic acids in tobacco was developed by derivatization,solid phase extraction and gas chromatography(GC). The tobacco samples were methylated with methanol and sulfuric acid. The organic acid ester was firstly extracted using solid-phase extraction in strong acidic medium,and then enriched with MCI-GEL and eluted with methanol. The eluent was determined by GC with a DB-5 capillary column and a splitless injection volume of 1. 0 μL at a detector temperature of 250 ℃. This method was applied in the determination of lactic acid,oxalic acid,propandioic acid,acetylpropionic acid,malic acid,citric acid,palmic acid,linoleic acid and stearic acid in tobacco samples. The recoveries were in the range of 92. 2%-102. 6% with relative standard deviations(RSD) of 2. 4%-3. 2%. The limits of quantitation(LOQ) for all analytes were between 0. 20 mg/L and 0. 36 mg/L. The method was accurate and sensitive,and could meet the actual requirements for the analysis of tobacco samples.更多还原