Abstract: A new analytical method was presented, allowing the rapid and simple determination of chlorine ion in pickles through direct reading. Pickle samples were pretreated by means of ultrasonic. The determination was performed using a chloride ion-selective electrode. The relative standard deviations (RSD) for five replicate determinations of chlorine ion using a total ionic strength adjustment buffer (TISAB) at pH 5.50 containing 0.20 g/L trisodium citrate and 0.80 mol/L potassium nitrate were 1.9%～2.9%. The spike recovery rates of chlorine ion from four types of pickle samples were 94.1%～105.6%. The limit of detection was 1.20 × 10-5 mol/L. There was no significant difference between this method and the national standard method as demonstrated by F test and t test analysis. This method was economic, simple, fast and suitable for rapid on-site determination of chlorine ion.

Key words: ion selective electrode (ISE), direct-reading method, chlorine ion, pickles, rapid determination, ultrasonic extraction