Unlocking the Mysteries of the Desorption-Ionization Mechanism via Separate Thermal and Charge Strategies.

Herein, a new strategy is employed to build a controllable thermal-coupled charge ionization (TCCI) device to elucidate the desorption-ionization mechanism of plasma ion sources. Efficient synergistic desorption and ionization are achieved within the TCCI device by independently controlling the desorption temperature and plasma charges. The TCCI device efficiently ionizes samples using abundant free electrons, charges, and active species from arc plasma.

Ultrafast Dual Activation of C(sp)-H and C(sp)-H Bonds in an Arc Plasma-Initiated Microdroplet.

This study demonstrates a method that utilizes arc plasma-induced microdroplet reactions to synthesize dual-activated products with C(sp)-N and C(sp)-O bonds starting from C-H bonds. This innovative process utilizes arc- and microdroplet-generated hydroxyl radicals and water dimer radical cations, opening new possibilities for the multisite derivatization of small molecules.

Pulsed Direct Current Arc-Induced Nanoelectrospray Ionization Mass Spectrometry.

This study explores the innovative field of pulsed direct current arc-induced nanoelectrospray ionization mass spectrometry (DCAI-nano-ESI-MS), which utilizes a low-temperature direct current (DC) arc to induce ESI during MS analyses. By employing a 15 kV output voltage, the DCAI-nano-ESI source effectively identifies various biological molecules, including angiotensin II, bradykinin, cytochrome C, and soybean lecithin, showcasing impressive analyte signals and facilitating multicharge MS in positive- and negative-ion modes. Notably, results show that the oxidation of fatty acids using a DC arc produces [M + O - H] ions, which aid in identifying the location of C═C bonds in unsaturated fatty acids and distinguishing between isomers based on diagnostic ions observed during collision-induced dissociation tandem MS.

Arc plasma for high-efficiency ionization and scavenging of plasticizers in wrap films.

Herein, ambient electric arc ionization mass spectrometry was used to examine 16 plasticizers in various wrap films, demonstrating high sensitivity (detection limit: <0.2 ng/mg) and precision (intra-/inter-day precision: <12 %). The ease of operation helps in the identification of wrap film and plasticizer analysis.

Arc-Induced Electrospray Ionization Mass Spectrometry.

Arc-induced electrospray ionization mass spectrometry (AESI-MS) was developed during which alternating current electrospray is simply achieved through the arc plasma. The AESI source exploits the arc's temperature and charge properties to generate aerosols consisting of charged microdroplets. The electrospray region, in which organic molecules are contained within microdroplets, partially overlaps with the arc plasma region.