A laser plasma ion source was used to ionize volatile organic compounds in a gas sample. The plasma was generated on a metal target in the intermediate vacuum region of ~0.3 Torr using a pulsed Nd:YAG laser with a wavelength of 1 μm. The resulting ions mass spectra were acquired using orthogonal time‐of‐flight mass spectrometer (O‐TOF MS). When using a copper target, the ions formed are simple complexes (CuM⁺) of copper ions with organic molecules. The possibility of online identification of trace amounts of alkanes in nitrogen and air, with a detection limit of ~10 ppb, was demonstrated. The ionization efficiency of volatile organic compounds through the formation of clusters with metal ions is 10⁻⁴ in terms of the quasimolecular complex ions. The rate constants of ion‐molecular reactions of copper ions with octane and water molecules in nitrogen and air are estimated.

中文翻译：

---

激光等离子体中形成的金属离子对有机分子的电离

激光等离子体离子源用于电离气体样品中的挥发性有机化合物。使用波长为1μm的Nd：YAG脉冲激光在〜0.3 Torr的中间真空区域内的金属靶上产生等离子体。所产生的离子质谱图是使用正交飞行时间质谱仪（O-TOF MS）获得的。当使用铜靶时，形成的离子是铜离子与有机分子的简单络合物（CuM ⁺）。证明了可以在线鉴定氮气和空气中痕量烷烃（检测限为〜10 ppb）的可能性。通过与金属离子形成团簇，挥发性有机化合物的电离效率为10 ^-4就准分子络合离子而言 估算了氮和空气中铜离子与辛烷和水分子的离子分子反应速率常数。