在气相色谱法测定烟草中非挥发性有机酸中,提出了用硫酸-甲醇(1+7)混合溶液作衍生试剂,在微波炉中于选定的条件下对所测定的有机酸进行衍生化。经酯化的溶液用二氯甲烷萃取,萃取液蒸缩至2 mL,分取1 μL进样作气相色谱分析。测定中采用AC 20毛细管柱及火焰离子化(FID)检测器并用戊二酸作内标,对7种非挥发性有机酸用标准加入法作回收及精密度试验,测得回收率在97.5%~103.3%之间,相对标准偏差(n=5)在1.6%~4.4%之间。用所提出的方法测定了烤烟、卷烟及白肋烟样品中非挥发性有机酸,测定结果与文献方法的结果相符。

In the gas chromatographic determination of non-volatile ogranic acids in tobacco, a modification of the derivatization of the organic acid was made by reacting with a mixture of H2SO4 and CH3OH (1+7) in a microoven under optimized working condition. The esterized solution was extracted with CH2Cl2, and the extract was evaporated to a volume of 2 mL. One μL aliquot was taken for GC analysis. AC 20 capillary column and FID detector were used in the analysis, and pentanedioic acid was used as internal standard. Recovery and precision for 7 non-volatile organic acids were tested by standard addition method, values of recovery and RSD′s (n=5) found were ranged from 97.5% to 103.3% and from 1.6% to 4.4% respectively. The proposed method was used in the determination of non-volatile organic acids in samples of flue-cured tobacco, cigarettes and burley tobacco, giving results in consistency with the results obtained by the method reported in literature.