Abstract: Objective    To study the feasibility of applying liquid chromatography-mass spectrometry（LC-MS/MS）to the quantitative determination of bisphenol A（BPA）in saliva. Methods   The LC-MS/MS method was applied to determine the BPA in saliva，in which isotopically labeled BPA（BPA-D16）was used as an internal standard. The specificity，accuracy and precision of the method was studied. Five dental composite resins，commonly used in clinical practice，were collected and incubated at 37°C in 1 mL artificial saliva. Then，the LC-MS/MS method was applied to determine the release of BPA in saliva at different time points.  Results    The LC-MS/MS method applied to determine the BPA in saliva showed good specificity with superior peak shape for BPA and BPA-D16. The concentration of BPA in saliva was linearly related to the peak area in the range of 0.1 - 50.0 ng/mL，and the regression equation was Y = 0.006X + 1.37（R2  = 0.9988）. The accuracy of the method was 97.5% - 101.2%，and the precision of intra- and inter- day assays of each concentration was less than 7.1%. The BPA-release study on dental composite resins by this method showed BPA release was the highest in the first day（24 h）. After 7 d，the total amount of BPA released from Neofil was（8.43 ± 0.16）ng/mL，followed by Beautifil Ⅱ（7.44 ± 0.40）ng/mL，Filtek Z350 XT（5.94 ± 0.33）ng/mL，Tetric N-Ceram（5.10 ± 0.06）ng/mL and Ceram. X One（0.64 ± 0.08）ng/mL. Conclusion    The LC-MS/MS method is suitable for the determination of BPA in saliva，and can be used to determine the level of BPA release from dental composite resin materials in saliva. 

Key words: bisphenol A, BPA, dental composite resin, liquid chromatography-mass spectrometry, LC-MS/MS, saliva

摘要： 目的    研究应用液相色谱串联质谱（LC-MS/MS）法测定唾液中双酚A（bisphenol A，BPA）含量的可行性。方法    应用LC-MS/MS法，以同位素标记的BPA（BPA-D16）作为内标，检测唾液中BPA含量，研究该方法的专属性、准确度与精密度。收集临床常用的5种牙科复合树脂，经聚合固化后置于1 mL人工唾液中，37°C孵育后，应用LC-MS/MS法测定不同时间点唾液中BPA的释放量。结果    LC-MS/MS法应用于测定唾液中BPA含量具有良好的专属性，BPA和BPA-D16的色谱峰形良好；BPA质量浓度在0.1 ~ 50.0 ng/mL范围内与峰面积呈线性关系，回归方程为Y = 0.006X + 1.37（R2 = 0.9988）；该方法准确度为97.5% ~ 101.2%，日内、日间精密度小于7.1%。应用该法检测5种临床常用的牙科复合树脂在唾液中的BPA释放情况，结果显示：5种树脂在唾液中孵育第1天内BPA释放量最高，7 d的BPA总释放量分别为Neofil树脂（8.43 ± 0.16）ng/mL、Beautifil Ⅱ树脂（7.44 ± 0.40）ng/mL、Filtek Z350 XT树脂（5.94 ± 0.33）ng/mL、Tetric N-Ceram树脂（5.10 ± 0.06）ng/mL、Ceram. X One树脂（0.64 ± 0.08）ng/mL。结论    LC-MS/MS法适用于唾液中BPA含量的测定，可用于检测牙科复合树脂材料在唾液中的BPA释放水平。

关键词: 双酚A, 牙科复合树脂, 液相色谱串联质谱法, 唾液