烟末水浸液pH值与烟碱蒸出率的相关性

测定了49种烤烟烟叶的烟末水浸液及加NaOH、加盐酸的昭阳B2F烟末水浸液的pH值,并对其烟碱进行了水蒸气蒸馏试验和总烟碱测定。结果表明:①烟叶的等级、产地不同,其烟末水浸液的pH值、烟碱蒸出量(率)亦不同;②烟末水浸液的pH值与烟碱的蒸出量无明显相关性,但与烟碱蒸出率呈线性正相关关系,相关系数为0.935;③当B2F烟末水浸液的pH值介于1.93~5.32时,烟碱蒸出率介于0~10.85%,烟碱蒸出率随着pH值的增大而增大,但变化趋势比较平缓;当水浸液pH值介于5.32~9.07时,烟碱蒸出率介于10.85%~86.33%之间,二者呈线性正相关关系,相关系数为0.995;当pH值介于9.07~10.93时,烟碱蒸出率介于86.33%~92.79%之间,二者的关系曲线再次趋于平缓。结论是烟碱水蒸气蒸馏,蒸出率和烟末水浸液的pH值相关。

Relationship Between pH Value of Aqueous Infusion of Tobacco Fine and Distillation Rate of Nicotine

The pH values of the aqueous infusion of 49 kinds of tobacco fine and the aqueous infusion of Zhaoyang B2F fine added with NaOH or HCl were determined,nicotine in the infusions was distilled with steam,and the content of total nicotine was determined.The results showed that:1)the pH value and nicotine content varied with the grade and growing area of leaf;2)there was no significant correlation between the pH value of aqueous infusion of tobacco fine and nicotine distillation yield,while the pH value linearly positively correlated with nicotine distillation rate,and the correlation coefficient was 0.935;3)when the pH value of aqueous infusion of B2F fine was between 1.93-5.32,the nicotine distillation rate was 0-10.85% and increased flat with the increase of pH value;when the pH value was between 5.32-9.07,the distillation rate was 10.85%-86.33% and linearly positively correlated with pH value(r=0.995);when the pH value was between 9.07-10.93,the distillation rate was 86.33%-92.79%,and their relationship curve became flat again.