摘要
建立了液相色谱-质谱检测奶粉和酸奶中11种全氟化合物（PFCs）的分析方法。分别考察了溶液离子强度和酸碱度对固相萃取效率的影响，结果表明，0．5～12．5mmol／LNaCl溶液的影响很小，且中性和微酸性条件下回收率较好。通过优化和比较，选用等体积的甲醇和0．01mol／L盐酸的甲醇溶液依次对奶粉中的PFCs进行萃取，对于酸奶则使用甲醇直接萃取，并用WAX柱对萃取液净化。以甲醇（A）和50mmol／L醋酸铵（B）为流动相进行梯度洗脱，洗脱时间为10min（或15min），流速1mL／min。内标法定量，奶粉和酸奶中11种PFCs的加标回收率分别为81％～111％和80％～118％，方法检出限为2—29ng／L。用该方法对市售国产和进口奶粉及酸奶样品中的PFCs进行了分析。
Two different methods were developed to measure 11 perfluorinated compounds （PFCs）, including nine perfluorinated acids and two fluorotelomer acids, in milk powder and yoghourt samples by high performance liquid chromatography - electrospray tandem mass spectrometry （ HPLC - ESI MS/MS）. The effects of ionic intensity and pH of loading solution on the extraction efficiency of PF- Cs were investigated. The results showed that there was no obvious effect when using concentration of NaCl in the range of 0. 5 - 12.5 mmoL/L and good recoveries could be obtained in the neutral and weak acid condition. The milk powder and yoghourt were extracted by methanol and methanol containing 0.01 mol/L HCl solution（ 1 ： 1, by volume） , respectively, and cleaned up by WAX cartridges. 11 PFCs were separated on a C18 reversed-phase column using gradient elution with methanol as mobile phase A and 50 mmol/L ammonium acetate as mobile phase B, and employing flow rate of 1 mL/min. The elution time was 10 min for milk powder and 15 min for yoghourt. Quantification was performed using the internal standard method. Under optimal conditions, the recoveries of 11 PFCs were in the range of 81% - 111% for milk powder and 80% - 118% for yoghourt. The detection limits ranged from 2 to 29 ng/L. The method was successfully applied to analyze PFCs in domestic and imported milk powder and yoghourt.
出处
《分析测试学报》
CAS
CSCD
北大核心
2009年第6期720-724,共5页
Journal of Instrumental Analysis
基金
国家高新技术研究计划(863)资助项目(2007AA06Z405)
中国科学院重要方向性资助项目(KZCX2-YW-420-1)
国家自然科学基金创新群体资助项目(20621703)
