基于ICP-MS法的包装用水基型胶粘剂中硼酸/硼砂残留量的快速检测

Rapid Determination of Boric Acid or Borax Residual in Water-based Adhesive for Packaging Using ICP-MS

目的为保证包装用水基型胶粘剂产品质量安全,研究建立一种包装用水基型胶粘剂中硼酸/硼砂的ICP-MS快速测定方法。方法样品用稀硝酸溶液涡旋震荡,使水基型胶粘剂完全分散破乳,取上层溶液经高速离心后用ICP-MS进行测定,优化了萃取硝酸溶液浓度和涡旋震荡萃取时间。结果获得的最佳萃取硝酸溶液体积分数为15%,涡旋震荡萃取时间为20 min。方法的检出限为9.43μg/kg,样品加标回收率为97.0%~103.0%,相对标准偏差小于3.0%(n=6)。结论建立的方法操作简便快速,灵敏度高,结果准确可靠,可适合于包装用水基型胶粘剂中硼酸/硼砂含量的快速测定;实际检测样品中有少量硼酸/硼砂残留,但均符合GB 9685规定的最大迁移限量6(mg/kg)的要求。

The paper aims to develop an analytical method inductively coupled plasma(ICP-MS)for rapid determining boric acid or borax in water-based adhesive to guarantee the quality of water-based adhesives for packaging.The water-based adhesives were completely dispersed and demulsified with nitric acid solution by the vortex oscillation.The solution was centrifuged at high speed and determined by ICP-MS,and the concentration of extracting nitric acid solution and the extracting time of vortex oscillation were optimized.The optimum concentration of nitric acid solution was 15%(volume fraction)and the extraction time of vortex oscillation was 20 minutes.The results showed that the detection limit of boron acid was 9.43μg/kg.The recoveries were in the range of 97.0% to 103.0% and the relative standard deviation was 3.0%(n=6).This method is simple,rapid and accurate,and suitable for rapid determination of boric acid or borax in water-based adhesive for packaging.A small amount of boric acid/borax residual is found in the actual samples,but they all meet the requirement of specific migration limit of 6 mg/kg in GB 9685.