Determination of chloride ion in dimethyl dicarbonate as food additives by ion exchange chromatography
Objiective: To establish a method for the determination of chloride ion in DMDC(dimethyl dicarbonate) as food additives by ion exchange chromatography.Method: Sample was dissluted by water after ultrasonic,chromatographic separation was performed on a SH-AC-1(25 cm×4.6 mm,5 μm) anion exchange column,Suppressed conductivity detection.Using sodium carbonate,sodium borate as the eluent,respectively.The effects of the types of eluent,eluent concentration on separation of chloride ion and interfering ion were investigated.The optimized chromatographic conditions for the determination of the chloride were as follows: 0.005 mol/L of sodium borate solution as eluent and flow rate of 1.0 mL/min.Results: Under these conditions,the chloride ions and other interfering ion can be completely separated in the sample.the resolution of peak attained 3.0 or more and the symmetry of peaks was better.The good linear calibration curve were obtained for the range of 0.1~5.0 mg/L with the linear relative coefficient more than 0.999,chloride ion detection limit(S/N=3) was 0.007 mg/L,The standard added recoveries were above 97.5% with good reproducibility.Conclusion: The method is simple,rapid,sensitive and accurate,It is suitable for determination of chloride ions in DMDC as food additives.