Abstract: A system and method for determining organic chlorine content in petroleum or petrochemical streams are disclosed. The system comprises an injection module configured to introduce a sample, consisting of a 204° C. cut of washed naphtha or equivalent, into a gas stream; a gas supply unit configured to deliver a gas mixture of approximately 80% oxygen and 20% inert gas selected from argon, helium, or nitrogen, into the injection module; a combustion unit maintained at approximately 800° C. to convert chlorine in the sample to chloride and oxychlorides; a titration cell, comprising: an electrolyte containing 75% acetic acid in water, a silver ion solution to react with chloride ions in the sample, resulting in a measurable electrochemical reaction; and a microcoulometer configured to measure the electric current required to replace consumed silver ions in the titration cell, wherein the measured current is indicative of the organic chlorine content.