摘要
烟碱含量是烟草质量的重要指标，目前测量烟草中烟碱的方法有硅钨酸重量法，紫外分光光度法，７２１分光光度法，这些方法各有利弊。在评价、收购烟草中均较困难。本法在上述方法的基础上分别以盐酸和水为浸取剂、三氯甲烷为萃取剂、溴甲酚绿和甲基红的混合试剂为指示剂，在最佳浸取、萃取、ｐＨ值等条件下，用标准硫酸溶液直接滴定烟碱的方法。本法准确、快速、简便。特别是在田间评价收购烟草时更有推广意义。
Nicotine is a special kind alkaloid in tobacco,and its content is an important quality index.At present,there are several methods to determine the content,such as silico tungastic acid weight method,ultraviolet spectrometry method and 721-spectrophotome method. With the advantages and disadvantages of the above methods,there are some difficulties in assessing and purchasing tobacco.In this paper,we will introduce a new method which is based on the above ones. It takes hydrochloric acid and water as soakers,trichlorod methane as extractant and the mixture reagent of bromocresol green and formaldehyde red as indicators.Then under the best condition of soaker,extraction and pH value,we determine the nicotine directly with criterion sulphuric acid.This method is characterized by accuracy,simplicity and high-speed,and has a great significance in assessing and purchasing tobacco on the field.
