ISO 22980-2020-06 pdf free.Tobacco—Determination of thecontent of total alkaloids as nicotine—Continuous-flow analysis methodusing KSCN/DCIC.
1.This document specifies a method for the determination of the content of total alkaloids as nicotine intobacco by continuous-flow analysis. This method is applicable to leaf samples, stems, reconstitutedtobacco sheet materials and tobacco blends.
2.The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies.Forundated references, the latest edition of the referenced document(including any amendments) applies.ISO3696, Water for analytical laboratory use —Specification and test methods
IS0 13276,Tobacco and tobacco products —Determination of nicotine purity —Gravimetric method usingtungstosilicic acid.
3.No terms or definitions are listed in this document.
4.An aqueous extract (see the next paragraph) of the tobacco is prepared and the total alkaloidscontent (as nicotine) of the extract is measured by reaction of sulfanilic acid and cyanogen chloride.Cyanogen chloride is produced in situ by reaction of potassium thiocyanate (KSCN) and sodiumdichloroisocyanurate (DCIC).The developed brown colour is measured at 460 nm.
A collaborative study has shown that the method gives equivalent results for water and 5 % acetic acidextracts. 5 % acetic acid extracts shall be used if total alkaloids (as nicotine) and reducing substances(see ISO 15153) or reducing carbohydrates (see ISO 15154) are to be carried out simultaneously.
5.Use only reagents of recognized analyticalgrade.All reagents shall be used according to good laboratorypractice.
Water used shall be high quality distilled or deionized (DI) water,free from organic contamination.Thewater used shall be level 1 as defined in IS0 3696.
For best results, vacuum filter all reagents through a 0,45 um filter (see Figure 1). If necessary, vacuumfilter all water used in the preparation of standards and for the sampler wash, otherwise degas thewater in another way.Add 1 ml of polyoxyethylene lauryl ether (5.1), 30 % solution to about 800 ml water and mix. Thendilute to 1 000 ml with water. Do not store the solution longer than a week and use a clean bottle for thefresh solution.ISO 22980 pdf download.