离子色谱-抑制型电导检测法同时测定食品级润滑油中的3种无机阴离子  

Simultaneous determination of three inorganic anions in food-grade lubricating oils by ion chromatography with suppressed conductivity detection

作　　者：张丽媛[1] 费旭东 邱丰[2] 林苗[1] 

机构地区：[1]东华大学化学化工与生物工程学院生态纺织教育部重点实验室,上海201620 [2]上海出入境检验检疫局工业品与原材料检测技术中心,上海200135

出　　处：《色谱》2015年第2期164-168,共5页Chinese Journal of Chromatography

基　　金：国家质检总局科技项目(2013IK016)

摘　　要：建立了离子色谱-抑制型电导检测同时测定食品级润滑油中Cl-、NO3-、SO2-4 -3种代表性无机阴离子的方法。样品经50％（v／v）甲醇水溶液超声提取，离心后所得下层水相用0．22μm混合纤维过滤膜净化，以15mmol／LKOH溶液为淋洗液，采用抑制型电导检测器进行检测，外标法定量。在上述条件下，Cl-、NO3-、SO2-4 -3种无机阴离子在0．10—20．00mg／L范围内具有良好的线性关系（R^2〉0．999）；检出限（S／N=3）为0．01-0．03mg／kg；在1．00、5．00、10．00mg／kg添加水平下，实际样品中3种阴离子的加标回收率为90．0％-103．6％，相对标准偏差为2．8％～5．7％。结果表明，该方法无需燃烧、灰化油相基质等繁琐耗时的前处理过程，可以快速、准确定量测定食品级润滑油中Cl-、NO3-、SO2-4 -3种无机阴离子的含量，适用于润滑油等油品中痕量无机阴离子的同时分离与测定。An ion chromatographic （IC） method with suppressed conductivity detection was developed for the simultaneous determination of Cl-, NO3-, SO2-4 in food-grade lubricating oils. After ultrasonic extraction with 50% （v/v） methanol aqueous solution and centrifugation, the sample in aqueous phase was purified with 0.22 μm hybrid fiber membranes, then analyzed by IC using 15 mmol/L KOH solution as eluent, and detected by a suppressed conductivity detec- tor. Effects of the concentration and flow rate of the eluent, and the concentration of the meth- anol aqueous solution on the detection of the three anions were investigated. Under the opti- mized separation conditions, the three anions were separated completely and the system peaks didn＇t interfere with the determination. The calibration curves showed good linearity （R^2〉 0. 999） in the range of 0. 10-20.00 mg/L. The limits of detection （LODs, S/N=3） were 0.01- 0. 03 mg/kg. The average recoveries of Cl-, NO3-, SO2-4 anions were 90. 0% - 103.6% with the relative standard deviations （RSDs） of 2.8% - 5.7%. This method avoids the time-consuming pretreatment process to burn or ash the oil phase matrix, and can determine the amounts of three inorganic anions （ Cl-, NO3-, SO2-4 ） in food-grade lubricating oils fast and accurately. It is suitable for simultaneously separating and detecting trace inorganic anions in lubricating oils orother oil products.

关 键 词：离子色谱 抑制型电导检测 无机阴离子 食品级润滑油 

分 类 号：O658[理学—分析化学]