Content Handbook F

Outline of method

38.1 Potassium - xylene method

The organic chlorine is converted by potassium in xylene to the chloride ion which is then titrated by the silver nitrate/ammonium hiocyanate procedure, or determined electrometrically.

38.2 Stepanov method

38.3 Oxygen flask method

The material is burnt in oxygen, oxidized by neutral hydrogen peroxide solution and the hydrochloric acid formed is determined by: (i) potentiometric titration with silver nitrate solution, or (ii) the use of dimercury dicyanide oxide with a comparative end point procedure, or (iii) in certain cases, direct titration with standard alkali.

Scope

38.3 Oxygen flask method

The method is applicable to the determination of the chlorine content of technical pesticides and their formulations, provided that the chlorine content of the sample is in excess of about 5% (Note 5). The method is thus, unsuitable for formulated products containing low levels of chlorine (about 0.5% or less) and a high proportion of inorganic filler.