目的 建立亲水作用色谱–蒸发光散射（HILIC-ELSD）法测定甲基纤维素中氯离子。方法 采用Thermo Acclaim Trinity P1 HILIC色谱柱（100 mm×3.0 mm，3μm）；流动相：乙腈–20 mmol/L乙酸铵水溶液（60∶40）（乙酸调pH 5.0）；体积流量：0.8 mL/min；柱温：30℃；进样量：10 μL；检测器漂移管温度105℃；氮气流量3.5 L/min。结果 氯离子在1～10 μg/mL与峰面积呈良好的对数线性关系，氯离子的最低检出质量浓度为0.5 μg/mL；平均回收率为99.4%，RSD值为1.6%。结论 此方法精密度好，回收率高，操作简单，能够准确测定甲基纤维素样品中的氯离子。

Objective To establish an HILIC-ELSD method for determination of chloridion in methylcellulose. Methods The separation was carried out on Thermo Acclaim Trinity P1 HILIC (100 mm×3.0 mm, 3 μm). The mobile phase was consisted of acetonitrile-20 mmol/L ammonium acetate solution (60:40, adjusted to pH 5.0 by acetic acid). The flow rate was 0.8 mL/min. The column temperature was 30℃, and volume of injection was 10 µL. The detector drift tube temperature was 105℃ and the nitrogen flow rate was 3.5 L/min. Results The linear relations was good between chloridion and peak area in the range of 1-10 μg/mL. The lowest detection concentration of chloride ion was 0.5 μg/mL. The average recovery rate was 99.4% with RSD value 1.6%. Conclusion The method has good precision, high recovery, and simple operation, which can accurately determine chloride ion content in methyl cellulose samples.