化妆品等健康相关产品中BrO_3^(-)、IO_3^(-)和NO_2^(-)的离子色谱测定法

Determination of Bromate, Iodate, Nitrite in Cosmetics and Foods by Ion Chromatography

目的建立化妆品、食品及食盐中的BrO3-、IO3-和NO2-的离子色谱(IC)测定法。方法选用高容量柱IonPacAS9-HC,以9.0mmol/LNa2CO3作淋洗液,流速1.3ml/min,外接水自动抑制再生,0.5g/L邻二甲氧基联苯胺盐酸盐溶液+5g/L溴化钾溶液+20%甲醇溶液+5.6%硝酸溶液作衍生剂,流速0.7ml/min,反应温度60℃,450nm波长检测,样品预处理后进样分析。结果BrO3-、IO3-和NO2-的线性范围分别为0.2～50、10～2500、1.0～150μg/L,r值分别为0.9998、0.9997、0.9994,检出限分别为0.008、0.02、0.10mg/kg,RSD分别为0.1%～1.5%,0.4%～1.0%,0.2%～7.2%,回收率分别为93.3%～100.0%,96%～107%,92.0%～109.0%。样品的酸度和共存离子对测定无影响。结论该方法的线性范围广、准确、灵敏,可满足化妆品、食品及食盐样品中痕量BrO3-、IO3-和NO2-的测定。

Objective To establish an IC method for determination of iodate, bromate, nitrite in cosmetics, food and salt by suppressed anion-exchange chromatography and ion-exchange with the addition of post column reagent. Methods A high capacity anion exchange column, Ion Pac9-HC column was used by 9 mmol/L sodium carbonate as eluent, and the flow rate was set up at 1.3 m[/min,an auto-suppression external water mode was used, 0.5 g/L o-dianisidine. 2HCI （ODA）＋5 g/L KBr＋20% methanel＋5.6% nitric acid was used as post column reagent, the flow was set up 0.7 ml/min. The post column reaction （PCR） temperature was 60 ℃ and the visible absorbance detection at 450 nm. Samples were pretreated and analysed. Results The influence of pH of samples and coexist anion on determination was discussed. The detection limit（MDL） of the present method was 0.008-0.10 mg/kg, the recovery rates of the method were 92.0%-109.0% and the relative standard deviation （RSD） were 0.1%- 7.2%. Conclusion This method is accurate, sensitive and suitable for trace analysis （μg/kg） of cosmetics and foods samples.