中文摘要：

激光光电离技术已广泛应用于质谱领域。基于单束激光的基质辅助激光解析（MALDI）质谱分析方法,已成为质谱分析生物大分子的标准方法之一。本文介绍的是另一种新的激光质谱分析方法：双步激光解析/激光电离质谱法（L2MS）,与MALDI相比,该方法不需要加入与样品形成共结晶的基质,同时可通过独立地改变两束激光的光强和波长达到优化质谱信号的目的。本文综述了该实验技术在氨基酸和短肽、环境污染物多环芳烃（PAHs）、高分子添加剂、矿物以及代谢产物等成分分析的最新进展,并展望该技术的应用前景。

英文摘要：

As a particular ionization technology,laser photoionization has been widely used in the field of the mass spectroscopy.Matrix assisted laser desorption ionization（MALDI）,where only one laser is used,has become the standard method in the biological mass spectrometry.In this review,a new mass spectrometric method based on two lasers is introduced,i.e.,Two-step laser desorption/laser ionization mass spectrometry（L2MS）.Comparing this method with MALDI,no matrix is needed to add on the substrate to form a good cocrystallization with the sample.The power and the wavelength of two laser beams can be optimized independently to maximize the signal.The recent research progress on the two-step laser desorption/laser ionization mass spectrometry and its applications on the analysis of the amino acids and peptides,the environmental pollutants PAHs（polycyclic aromatic hydrocarbons）,the chemical additives,the mineral composition and the metabolic products are introduced.Future prospect in this filed is provided in the end.