超高效液相色谱-傅里叶变换离子回旋共振质谱法解析溶解性有机质的化学多样性  

Chemical diversity of dissolved organic matter revealed by ultra performance liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry

作　　者：马超 倪洪星 戚羽霖 MA Chao;NI Hongxing;QI Yulin(Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University,Tianjin 300072,China;Sinochem Asset Management Co.,Ltd.,Beijing 100045,China;Haihe Laboratory of Sustainable Chemical Transformations,Tianjin 300192,China)

机构地区：[1]天津大学表层地球系统科学研究院,地球系统科学学院,天津300072 [2]中化资产管理有限公司,北京100045 [3]物质绿色创造与制造海河实验室,天津300192

出　　处：《色谱》2023年第8期662-672,共11页Chinese Journal of Chromatography

基　　金：国家自然科学基金(42230509,42277456)。

摘　　要：采用傅里叶变换离子回旋共振质谱(FT-ICR MS)结合四极检测技术,对水体、气溶胶和土壤样品中溶解性有机质(DOM)进行在线超高效液相色谱(UPLC)-质谱分析。3种环境样品主要组成为强极性含盐化合物、富氧低饱和度的单宁酸类化合物、低氧高饱和度的木质素类化合物及蛋白/氨基糖类化合物。UPLC-FT-ICR MS适合分析DOM的分子组成,在水体、气溶胶和土壤DOM中能够有效匹配分子式的质谱峰数目分别为12 027、15 593和8 029个。质谱数据经可视化处理后发现,水体样品的特有组分主要出现在0.1<O/C<0.5、1.0<H/C<1.7区域,为低氧高饱和度的木质素组分;气溶胶样品的特有组分主要出现在0.4<O/C<1.0、1.5<H/C<2.0区域,属于碳水化合物的分布范围;土壤样品在不同极性洗脱段有不同的特有组分,亲水段的特有组分主要出现在0.6<O/C<1.0、0.5<H/C<1.0区域,为单宁酸类化合物,而疏水段的特有组分主要为木质素类化合物。本研究以探索的方式,提出了采用UPLC-FT-ICR MS分析环境体系DOM的方法,选用不同极性的流动相利用UPLC对环境样品中的DOM进行分离,并结合高分辨质谱分析,表征了DOM分离为不同极性组分后的分子组成以及其可能的化合物类型,为揭示更全面的DOM分子组成提供了技术支持。Dissolved organic matter(DOM)is a highly complex and heterogeneous mixture that exists in various environments,including rivers,oceans,soils,and atmospheric aerosols.DOM plays a crucial role in biogeochemical cycles and significantly influences the environment by regulating water quality,changing the climate,and transporting pollutants.Therefore,clarif⁃ying the detailed molecular composition of DOM is essential to obtain a better understanding of its physical and chemical properties,thereby enabling further elucidation of its biogeochemical behavior.In this study,Fourier transform ion cyclotron resonance mass spectrometry(FT⁃ICR MS)combined with quadrupole detection(QPD)was used to conduct the online ultra performance liquid chromatography(UPLC)⁃MS analysis of DOM in water,aerosol,and soil samples collected in Tianjin,China.The samples were extracted with pure water and filtered through a glass fiber membrane(0.45μm).The DOM in the samples was then enriched by solid⁃phase extraction(SPE)and redissolved in water⁃acetonitrile(1∶1,v/v)at mass concentration of 200 mg/L for the LC⁃MS experiments.The mobile phases used for UPLC were water containing 0􀆰1%(v/v)formic acid(A)and acetonitrile containing 0􀆰1%(v/v)formic acid(B).The gradient elution procedure was as follows:0-5 min,0B;5-11 min,0B-95%B;11-25 min,95%B;25-28 min,95%B-0B;28-30 min,0B.The flow rate was 0􀆰1 mL/min,and the injec⁃tion volume was 10μL.The UV wavelength was set at 274 nm.MS detection was performed in negative electrospray ionization(ESI(-))mode with a capillary voltage of 5.0 kV,and the MS data were collected in broadband(m/z 150-1000)and QPD modes.The transient data size was set to 2M,the free induction decay signal length was 0.74 s,and the ion accumulation time was 0.030 s.Four chromatographic peaks were observed in the chromatograms.The first peak was identi⁃fied as salt adduct compounds containing sodium formate.The three other peaks contained complex components,such as oxygen⁃rich,unsaturated tannin⁃like compound

关 键 词：超高效液相色谱 傅里叶变换离子回旋共振质谱 溶解性有机质 可视化表征 化学多样性 

分 类 号：O658[理学—分析化学]