Method for detecting chlorine content in crude benzene

The invention relates to a method for detecting the chlorine content in crude benzene, which comprises the following steps: (1) bringing a crude benzene sample into a combustion tube by carrier gas, mixing with oxygen, combusting, and converting the chlorine element in the sample into hydrogen chloride to obtain a combustion product containing hydrogen chloride; (2) the combustion product enters the titration cell and reacts with a titrant Ag < + > in the titration cell as follows: Ag < + > + Cl -AgCl ; wherein the electrolyte in the titration cell is an acetic acid solution; and (3) reducing the concentration of Ag in the titration cell due to Ag < + > consumed in the step (2), so that the potential difference between the indicator electrode pairs is changed, and calculating the chlorine content in the crude benzene. According to the method disclosed by the invention, the concentration detection range can be expanded under the condition that an analysis result is not influenced, the analysis effici