Ammonium hydroxide enhancing electrospray response and boosting sensitivity of bisphenol A and its analogs
Ammonium hydroxide enhancing electrospray response and boosting sensitivity of bisphenol A and its analogs
复制标题
氢氧化铵增强电喷雾响应并提高双酚 A 及其类似物的灵敏度
DOI：
10.1016/j.talanta.2018.02.033
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发表时间：
2018
期刊：
影响因子：
6.1
通讯作者：
Chen Jiping
中科院分区：
文献类型：
--
作者：
Tan Dongqin;Jin Jing;Wang Longxing;Zhao Xueqin;Guo Cuicui;Sun Xiaoli;Dhanjai;Lu Xianbo;Chen Jiping
作为准确定量双酚类化合物最重要的分析技术之一，液相色谱-电喷雾串联质谱（LC-ESI-MS）在负离子模式下表现出相对较弱的ESI响应，这大大降低了它们的灵敏度，并限制了它们在痕量水平的检测，特别是在复杂样品如血液中。基于双酚分子在碱性条件下易发生去质子化反应，探索了柱后注入氨水（NH3·H2O）的方法，以提高双酚A及其8种类似物的电离效率，提高其分析灵敏度。考察了NH3·H2O质量浓度和流量对响应强度和稳定性的影响。在NH3·H2O加入量为2%（w/w）、流速为4 μL min−1的最佳条件下，双酚类化合物的仪器检测限大大降低到0.001-0.04 ng mL−1，比不加入NH3·H2O的结果低2 ~ 28.6倍，TBBPA除外（两种情况下均为0.03 ng mL− 1）。BPA及其类似物在三个不同浓度水平的仪器重复性的相对标准偏差（RSD）在1.2- 20%的范围内。此外，血清提取物中双酚（TBBPA除外）分析的基质效应（90-111%）比未进样时（43-111%）降低。结果表明，改进的仪器分析方法结合适当的前处理技术，对复杂生物样品中双酚类化合物的分析更具有可行性。
As one of the most important analytical techniques for accurate quantification of bisphenol compounds, liquid chromatography coupled to online electrospray ionization (ESI) tandem mass spectrometry exhibits relative weak ESI response in negative mode, which greatly reduces their sensitivity and limits their detection at trace levels, especially in complex samples such as blood. Based on the facilitated deprotonation of bisphenol molecule under alkaline condition, post-column injection of ammonium hydroxide (NH3·H2O) to mass spectrometer was explored to enhance the ionization efficiency of BPA and its eight analogs and improve their analytical sensitivity. Parameters effecting response intensity and stability were investigated, including mass concentration and flow rate of NH3·H2O. Under the optimal conditions with the addition of 2% (w/w) of NH3·H2O at 4 μL min−1, the instrument detection limits for bisphenol compounds were greatly lowered to 0.001–0.04 ng mL−1, which were 2–28.6 times lower than the result obtained without injecting NH3·H2O, except TBBPA (0.03 ng mL−1in either case). The relative standard deviations (RSDs) for instrument repeatability of BPA and its analogs at three different concentration levels were in a range of 1.2–20%. Furthermore, a decreased matrix effects (90–111%) for bisphenols (except TBBPA) analysis in serum extracts were found compared with the result obtained without NH3·H2O injection (43–111%). The results demonstrated that the improved instrumental method coupled with suitable pretreatment techniques is more feasible to analyze bisphenol compounds in complex bio-samples.