在线渗析-离子色谱法同时测定化妆品中的亚硝酸盐和硝酸盐

Simultaneous determination of nitrite and nitrate in cosmetics by on-line dialysis-ion chromatographic

目的：采用在线渗析技术与离子色谱法联用测定化妆品中的亚硝酸盐和硝酸盐。方法：样品经纯水溶解振荡、超声提取后,离心所得的上清液经在线渗析后进入分离柱分离,采用Metrosep A Supp4阴离子交换柱,以1.8 mmol/LNa2CO3与1.7 mmol/L NaHCO3作为淋洗液,化学抑制电导检测。结果：方法中NO2^-和NO3^-的检出限为0.20 mg/kg和0.25 mg/kg。样品加标回收率在91%-111%之间,精密度RSD分别为2.4%和1.9%。结论：该法快速、灵敏、准确,高效自动化,可同时测定化妆品中的亚硝酸盐和硝酸盐含量。

Objective： A method for measuring nitrite and nitrate in cosmetics by combined technology of on - line dialysis and ion chromatography was eatablished. Methods：The sample was extracted by mixing, ultrasonic and centrifuge, the supernatant liquid was then on -line treated with dialysis. The nitrite and nitrate were separated with the Metrosep A Supp4 Anion Exchanger Column. A mixed solution of 1.8 mmol/L Na2CO3 and 1.7 mmol/L NaHCO3 was used as eluent and was detected by suppressed conductivity detector. Results： DL of the NO2^- and NO3^- in this method was 0. 20 and 0. 25 mg/kg. The average recoveries were in the range of 91% - 111%. Conclusion： This method, which is fast, sensitive, extract and efficient automation, can be used to simultaneous determine nitrite and nitrate in cosmetics.