新型进样瓶-气相色谱质谱法测定烟叶中的24种有机酸

Determination of 24 Organic Acids in Tobacco Leaf via Novel Sampling Bottle-gas Chromatography-mass Spectrometer

建立了一个新型进样瓶,结合气相色谱质谱法(GC-MS)可以测定烟叶中的24种有机酸。结果表明:新型进样瓶可以集提取、过滤、干燥、衍生化反应和进样功能为一体,在一定程度上减少操作步骤,缩短前处理时间,可以保障样品检测的平行性和稳定性;利用新型进样瓶,以二氯甲烷为提取剂,N,O-双(三甲基硅烷基)三氟乙酰胺(BSTFA)为衍生化试剂,将提取液在40℃下反应60 min,衍生化后的样品利用气相色谱质谱法,选择离子模式进行检测。该方法在0. 5～50 mg/L范围内,线性关系较好(R> 0. 99),检出限为0. 1～6. 8μg/g,加标回收率在85%～104%之间,相对标准偏差在1. 1%～5. 1%之间;利用该方法对不同生长期的烟叶进行检测,发现有机酸物质具有差异性。该方法操作简单、重复性好、准确度高,可以满足烟草及相关样品中有机酸的检测要求。

A novel sampling bottle was developed to couple with gas chromatography-mass spectrometer ( GC-MS) for the determination of 24 organic acids in tobacco leaf.The results show that the pretreatment including extraction, filtering, removing the water, derivation and sampling could be finished in one step by the novel sampling bottle,which can make the procedure simpler, time saving and having good repeatability.Based on the pretreatment device, the tobacco leaf sample was extracted by dichloromethane, then derivatized with N,O-bis( trimethylsilyl) trifluoroacetamide under 40 ℃ for 60 min.The separation of 24 organic acids including formic acid, acetic acid, etc.,was performed by GC-MS on selected ion mode.In the range of 0. 5~ 50 mg /L, the linearity was acceptable ( correlation coefficient R>0. 99).The spiked recoveries of real sample were 85%~ 104% with the RSD in the range of 1. 1%~ 5. 1%.With the established test method,different contents of organic acids in different type tobacco leaves were found. With the simplification, good reproducibility,proper accuracy, the developed method can be used for the determination of 24 organic acids in tobacco samples.