气相色谱-三重四极杆质谱法测定果汁中邻苯二甲酸酯含量

Determination of phthalic acid esters in juice using gas chromatography-tandem mass spectrometry

目的建立一种同时测定果汁中16种邻苯二甲酸酯的气相色谱一三重四极杆质谱（GC-MS／MS）方法，了解安阳市内销售的果汁中邻苯二甲酸酯含量的现状。方法样品经正己烷提取，固相萃取玻璃小柱净化，萃取液经氮吹浓缩后，以GC-MS／MS测定，外标法定量。结果16种邻苯二甲酸酯在24min内流出并完全分离，在5～5000μg／L范围内相关系数r^2均〉0．99，在3个水平的加标试验中，RSD为0．1％～6．1％，样品加标回收率为78％～106％，定性检出限为0．1～0．5μg／L。结论该方法通过优化气相色谱条件，使16种邻苯二甲酸酯得到较好分离；选取丰度高的特征离子、最佳的碰撞能量，用GC-MS／MS检测特征离子的二级离子，可减少干扰，避免假阳性的出现，提高灵敏度。该方法操作简单、准确度和精密度高，适用于果汁中邻苯二甲酸酯的检测和确证。

Objective To optimize gas chromatography and mass spectrometry conditions, establish a method for determination of 16 phthalic acid esters in juice using gas chromatography-tandem mass spectrometry （GC-MS/MS） , and investigate the contamination level in juice in Anyang City. Methods The samples were extracted by hexanes, purified with ProElut PSA Glass column, concentrated by nitrogen drying and then determined by GC-MS/MS using external standard method. Results 16 phthalic acid esters were separated completely within 24 minutes. The linearity of 16 phthalic acid esters was 5-5 000 μg/L with correlation coefficients （ r2 ） above 0. 99. The relative standard deviations （RSDs） were in the range of 0. 1% -6.1%. Recoveries ranged from 78% to 106% for all compounds at three different spiked levels. The limits of detection were 0. 1-0.5 μg/L. Conclusion 16 phthalic acid esters were better separated in the suitable conditions of gas chromatography. Choosing the highest and most abundant mass precursor ion and the best collision energy, the detection of product ion by GC-MS/MS could reduce the background and improve the sensitivity. The method was simple, accurate and sensitive. It was suitable for the determination of phthalic acid esters in juice.