The ions in the negative glow were examined at pressures of about 0.4 mm and currents of about 0.2 ma. Most of the work was done with argon but some measurements were made with helium and with helium-argon and argon-krypton mixtures. To clarify the role of impurities, some work was done...
The monoisotopic mass of an ion or molecule is defined as an exact mass and is determined by summing each mass of the most abundant isotope (e.g. 1H=1.00782, 12C=12.00000, 16O=15.99491, 14N=14.00307) present in the chemical formula. ...
Adding a makeup solvent (absolute ethyl alcohol, methanol, fluorobenzene, or acetone) to the argon gas stream at the exit of the DART ion source can result in 1–2 orders of magnitude increase in detection signals. The sensitivity attainable by Ar-DART was found to be comparable to that ...
The technique of Ion Kinetic Energy Spectroscopy (I.K.E.S.) is described and results obtained with a sample of argon gas are discussed. When coupled with conventional mass spectroscopy, the technique enables the route to formation of the ions in the mass spectrum to be deduced. It can ...
The mass‐resolved ion energy distribution (IED) at the grounded electrode has been determined in a 13.56‐MHz parallel‐plate plasma in argon. The IED is determined of Ar+, Ar2+, Ar2+, ArH+, H3O+, and H3+for several plasma conditions. At pressures higher than 10 mTorr, collisions in...
argon ionscomparative evaluationsenvironmental materialsion microprobe analysisionsprogress reportsputteringResonance ionization mass spectrometry (RIMS) has recently been developed into a useful technique for isotope ratio measurements. Studies performed in our laboratory [1–6] have been reported for a ...
Solution aerosols are injected into an inductlvety coupled argon plasma (ICP) to generate a relatively high number density of positive ions derived from elemental constituents. A small fraction of these ions is extracted through a sampling orifice into a differentially pumped vacuum system housing an...
where ions selected in the first quadrupole are collided with anoble gas(e.g., argon) to produce fragment ions. The third quadrupole selects for the fragmentm/z. These steps remove most environmental interferences. With careful selection of fragment ions, they are often sufficient to...
A particular m/z value of interest is selected from the mass spectrum and is directed into a collision cell that contains a neutral gas (argon, for example). The ion is vibrationally excited by collision with the target gas, a process known as collision induced dissociation. This generates ...
Charge-exchange chemical ionization mass spectrometry (using a 15% mixture of methane in argon) yields abundant M/sup +/, M + H/sup +/, M + C/sub 2/H/sub 5... WJ Simonsick,RA Hites - 《Analytical Chemistry》 被引量: 76发表: 1984年 Direct observation of the products produced by ...