Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China.
Anal Chem. 2017 Oct 3;89(19):10256-10263. doi: 10.1021/acs.analchem.7b01695. Epub 2017 Sep 13.
There are two challenges in oligonucleotide detection by liquid chromatography coupled with mass spectrometry (LC-MS), the serious ion suppression effects caused by ion-pair reagents and the low detection sensitivity in positive mode MS. In this study, highly concentrated alcohol vapors were introduced into an enclosed electrospray ionization chamber, and oligonucleotides could be well detected in negative mode MS even with 100 mM triethylammonium acetate (TEAA) as an ion-pair reagent. The MS signal intensity was improved 600-fold (for standard oligonucleotide dT15) by the isopropanol vapor assisted electrospray, and effective ion-pair LC separation was feasibly coupled with high-sensitive MS detection. Then, oligonucleotides were successfully detected in positive mode MS with few adducts by propanoic acid vapor assisted electrospray. The signal intensity was enhanced more than 10-fold on average compared with adding acids into the electrospray solution. Finally, oligonucleotides and peptides or histones were simultaneously detected in MS with little interference with each other. Our strategy provides a useful alternative for investigating the biological functions of oligonucleotides.
在液相色谱-质谱联用（LC-MS）检测寡核苷酸时存在两个挑战，即离子对试剂引起的严重离子抑制效应和正模式 MS 检测的低灵敏度。在本研究中，将高浓度的醇蒸气引入封闭的电喷雾电离室中，即使使用 100mM 的三乙铵乙酸盐（TEAA）作为离子对试剂，寡核苷酸也能在负模式 MS 中得到很好的检测。异丙醇蒸气辅助电喷雾将 MS 信号强度提高了 600 倍（对于标准寡核苷酸 dT15），并实现了有效的离子对 LC 分离与高灵敏度 MS 检测的有效结合。然后，通过丙酸蒸气辅助电喷雾，寡核苷酸可以在正模式 MS 中成功检测到，且副产物较少。与将酸添加到电喷雾溶液中相比，平均信号强度增强了 10 倍以上。最后，寡核苷酸和肽或组蛋白可以在 MS 中同时检测，彼此之间几乎没有干扰。我们的策略为研究寡核苷酸的生物学功能提供了一种有用的替代方法。
