The invention provides a
continuous flow method for measuring total
alkaloid in tobacco or tobacco products. In the method,
potassium thiocyanate and
sodium dichloro isocyanurate are adopted to carry out reactions to generate
cyanogen chloride on line. The
cyanogen chloride can carry out reactions with total
alkaloid (calculated in the form of
nicotine) in tobacco or tobacco products to break off the
pyridine rings of
nicotine, and then further carries out reactions with p-aminobenzene
sulfonic acid. The reaction products are measured by a chromometer at 460 nm. The method uses a buffer
system to control the pH value of the
reaction system in a range of 6.0 to 7.5, and the buffer
system is composed of a
buffer solution A and a
buffer solution B. The
buffer solution A is prepared by the following steps: weighing
disodium hydrogen phosphate and
trisodium phosphate, placing the weighed substances in a
beaker, dissolving the substances with water, transferring the solution to a
volumetric flask (1L), and adding water into the
volumetric flask until the water reaches the scale. The buffer solution B is prepared by the following steps: weighing p-aminobenzene
sulfonic acid,
disodium hydrogen phosphate,
sodium dihydrogen
phosphate, and
sodium citrate, placing the weighed substances into a
beaker, dissolving the substances with water, transferring the solution to a
volumetric flask (1L), and then adding water into the volumetric flask until the water reaches the scale.