An Ammonium Bicarbonate-Enhanced Stable Isotope Dilution UHPLC-MS/MS Method for Sensitive and Accurate Quantification of Acrolein鈥揇NA Adducts in Human Leukocytes

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• 作者：Ruichuan Yin ; Shengquan Liu ; Chao Zhao ; Meiling Lu ; Moon-shong Tang ; Hailin Wang
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：March 19, 2013
• 年：2013
• 卷：85
• 期：6
• 页码：3190-3197
• 全文大小：374K
• 年卷期：v.85,no.6(March 19, 2013)
• ISSN：1520-6882

文摘

Acrolein (Acr), a ubiquitous environmental pollutant, can react directly with genomic DNA to form mutagenic adducts without undergoing metabolic activation. To sensitively and accurately quantify Acr鈥揇NA adducts (including structural isomers and stereoisomers) in human leukocytes, we developed an enhanced stable isotope dilution ultrahigh performance liquid chromatography (UHPLC)鈥搕andem mass spectrometry (MS/MS) method using ammonium bicarbonate (NH₄HCO₃), which is thermally unstable and degrades readily to carbon dioxide and ammonia in heated gas phase. Interestingly, ammonium bicarbonate (as an additive to the mobile phase) not only improves the protonation of AcrdG adducts but also suppresses the formation of MS signal-deteriorating metal鈥揂crdG complexes during electrospray ionization, leading to the enhancement of their MS detection by 2.3鈥?.7 times. In contrast, routinely used ammonium salts (ammonium acetate and ammonium formate) and formic acid do not show similar enhancement. The developed method is potentially useful for enhancing ESI-MS detection of other modified 2鈥?deoxyribonucleosides that have difficulty in protonation and may form excess metal complexes during electrospray ionization. The limits of detection (LODs, S/N = 3) are estimated to be about 40鈥?0 amol. By the use of the developed method, we found that the Acr adducts of three nucleotides (dG, dA, and dC) can be detected in human leukocytes. In addition to the known 纬-AcrdG, 伪-AcrdA is also identified as an Acr-adduct of high abundance (2.5鈥?0 adducts per10⁸ nts).