牛乳中16种全氟化合物及前体物质的改进型分散固相萃取-超高效液相色谱-串联质谱快速测定法

Determination of sixteen perfluorochemical compounds and perfluorochemical precursors in milk by modified dispersion solid phase extraction combined with ultra high performance liquid chromatography tandem mass spectrometry

目的建立牛乳中16种全氟化合物及前体物质的改进型分散固相萃取(QuEChERS)-超高效液相色谱-串联质谱快速测定法。方法向3.0 g牛乳中加入浓度为100μg/L的(13)C4-MPFOA及(13)C4-MPFOS内标100μl,样品经离心后使用改进型QuEChERS试剂净化,收集净化液经氮气吹干定容,使用Hypersil Gold色谱柱(200 mm×2.1 mm,1.9μm),以10 mmol/L的乙酸铵缓冲液-乙腈为流动相进行梯度洗脱,使用ESI离子源正离子进行选择性离子扫描。结果16种全氟化合物及前体物质在测定浓度范围内线性关系良好,各测定组分相关系数r≥0.999,方法平均回收率为70.8%~112.5%之间,RSD为8.4%~12.6%。16种全氟化合物的检出限为0.04~0.10μg/kg,定量下限为0.12~0.30μg/kg。结论该方法具有前处理过程简单,重现性好,灵敏度、准确度及精密度较高,适用于牛乳基质中全氟化合物与全氟化合物前体物质的测定。

Objecetive To develop a method for the determinaton of perfluorochemical compounds and perfluorochemical precursors in milk by modified dispersive solid phase extraction method(QuEChERS)purification and determination by ultra high performance liquid chromatography tandem mass spectrometry.Methods Totally 3 g milk was added 100μl 100μg/L internal standard(13)C4-MPFOA and(13)C4-MPFOS and purified by modified QuEChERS after centrifugation and purified liquid concentrated by nitrogen was constant volume before tests.Hypersil Gold column(200 mm×2.1 mm,1.9μm)was used for analysis.Gradient elution was performed using 10 mmol/L ammonium acetate buffer and acetonitrile.Selective ion scanning detection was employed at positive electrospray ionization.Results The method showed good linear relationship between the concentration range,r≥0.999,the spiked recovery ranged 70.8%-112.5%,precision ranged 8.4%-12.6%,LOD ranged 0.04-0.10μg/kg and LOQ ranged 0.12-0.30μg/kg.Conclusion The method exhibits high sensitivity,high precision and accuracy,and is applicable to the determination of perfluorochemical compounds and perfluorochemical precursors in milk.