Somogyi Arpad, Oh Chu-Ha, Smith Mark A, Lunine Jonathan I
Department of Chemistry, University of Arizona, 1306 E. University Street, Tucson, AZ 85721, USA.
J Am Soc Mass Spectrom. 2005 Jun;16(6):850-9. doi: 10.1016/j.jasms.2005.01.027. Epub 2005 Mar 29.
Laboratory simulations have been carried out to model chemical reactions that possibly take place in the stratosphere of Saturn's moon, Titan. The aerosol products of these reactions (tholin samples) have been systematically analyzed by mass spectrometry using electrospray ionization (ESI) and laser desorption (LD). A wide variety of ions with a general formula C(x)H(y)N(z) detected by ultrahigh resolution and accurate mass measurements in a Fourier transform/ion cyclotron resonance (FT-ICR) cell reflect the complexity of these polymeric products, both in chemical compositions and isomeric distributions. As a common feature, however, tandem mass spectral (MS/MS) data and H/D exchange products in the solution phase support the presence of amino and nitrile functionalities in these (highly unsaturated) "tholin" compounds. The present work demonstrates that ESI-MS coupled with FT-ICR is a suitable and "intact" method to analyze tholin components formed under anaerobic conditions; only species with C(x)H(y)N(z) are detected for freshly prepared and harvested samples. However, when intentionally exposed to water, oxygen-containing compounds are unambiguously detected.
已进行实验室模拟，以模拟可能在土星卫星泰坦平流层中发生的化学反应。这些反应的气溶胶产物（索林样品）已通过使用电喷雾电离（ESI）和激光解吸（LD）的质谱法进行了系统分析。通过在傅里叶变换/离子回旋共振（FT-ICR）池中进行超高分辨率和精确质量测量检测到的各种通式为C(x)H(y)N(z)的离子，反映了这些聚合产物在化学成分和异构体分布方面的复杂性。然而，作为一个共同特征，串联质谱（MS/MS）数据和溶液相中的H/D交换产物支持这些（高度不饱和）“索林”化合物中存在氨基和腈官能团。目前的工作表明，ESI-MS与FT-ICR联用是分析在厌氧条件下形成的索林成分的一种合适且“完整”的方法；对于新鲜制备和采集的样品，仅检测到通式为C(x)H(y)N(z)的物种。然而，当故意暴露于水时，明确检测到了含氧化合物。
