新鲜三七样品经水冲洗干净后,于80 ℃杀青、烘干、粉碎、过筛,分取2.000 0 g,加入水40 mL,于90 ℃水浴提取60 min,冷却至室温。用水稀释至50 mL,离心3 min。分取上清液8 mL,加入2 mL正己烷,涡旋1 min,离心3 min。吸取下层水相,过0.22 μm水相滤膜,滤液供离子色谱分析。以IonPac AS15色谱柱为固定相,以30 mmol·L^-1氢氧化钾溶液作淋洗液,在1.0 mL·min^-1流量下进行等度洗脱,所得氯离子用电导抑制检测器分析。结果显示:氯离子的质量浓度在0.05~20.00 mg·L^-1内与其对应的峰面积呈线性关系,检出限(3s)为0.005 mg·L^-1;对实际样品进行3个浓度水平的加标回收试验,氯离子的回收率为85.4%~105%,测定值的相对标准偏差(RSD,n=6)为2.8%~4.2%。方法用于实际样品分析,并与文献中的高温干法灰化法进行比对,测定值基本一致,前者精密度更优。

The fresh Panax notoginseng sample was washed with water, blanched at 80 ℃, dried, crushed and sieved. An aliquot (2.000 0 g) was taken and mixed with 40 mL of water, and the mixture was extracted in 90 ℃ water bath for 60 min. After cooling to room temperature, the mixtue was diluted to 50 mL with water, and centrifuged for 3 min. An aliquot (8 mL) of supernatant was taken, and 2 mL of n-hexane was added. The mixed solution was swirled for 1 min, and centrifuged for 3 min. The lower aqueous phase was taken, and passed through a 0.22 μm aqueous filter membrane. The filtrate was used for ion chromatography analysis. IonPac AS15 chromatographic column was used as the stationary phase, and 30 mmol·L^-1 potassium hydroxide solution was used as the eluent. The chloride ion was obtained by isocratic elution at a flow rate of 1.0 mL·min^-1, and analyzed by the conductivity inhibition detector. As found by the results, values of mass concentration and peak area of chloride ion were linearly related in the range of 0.05-20.00 mg·L^-1, with detection limit (3s) of 0.005 mg·L^-1. The spiked recovery test was carried out on the actual sample at three concentration levels, giving results of recovery of chloride ion in the range of 85.4%-105%, and RSDs (n=6) of the determined values ranged from 2.8% to 4.2%. The proposed method was applied to the analysis of actual sample, and compared with high temperature dry ashing method given from reference. The determined values were basically consistent, and the proposed method had better precision.