The Precursor scan. A new type of experiment in neutralization–reionization mass spectrometry

Abstract

A new scan technique utilizing the tandem quadrupole acceleration-deceleration mass spectrometer is described The technique is based on combined monitoring of neutral and ion precursors that fragment following collisional electron transfer to give rise to a selected low-mass neutral species and its ion, respectively. P O is found to be a stable neutral species formed by dissociations of a variety of oxidized phosphorus compounds, such as di-and trialkyl phosphites, phosphates and phosphonic esters. These compounds can be selectively monitored through PO' precursor scans in multi-component mixtures. Interferences from isobaric neutral species, 3sCIC, CH,S, CH, 30SiH,', and their precursors are discussed. Neutralization-reionization spectra of phosphoruscontaining radicals, PO', CH,OPH', CH,OPOH, 'P(OCH,), and (CH,O),PO', are also reported. co+' 15.16 SO+. 17.18 CS + . , I 9 HCN+' 20.21

Selective Quantitation of Organic Sulfur with the Precursor Scan Method of Neutralization-Reionization Mass Spectrometry

“…The precursor mass resolution in the precursor scan depends on the precursor and marker mass and the kinetic energy release in the fragmentation producing the neutral marker, as discussed previously. 17 Chemicals were purchased from Aldrich or Baker and used without further puriÐcation. Mixture samples were prepared by serial dilution of sulfur-containing compounds in a base oil solution.…”

Neutralization-reionization mass spectrometry applied to organometallic and coordination chemistry (update: 1994-1998)

“…Studies of the origin and chemistry of neutrals that arise in a variety of mass spectrometry experiments have been undertaken by the Turecek group, which used their QADQ instrument to determine ionic precursors for speci®c neutrals that originated from the dissociation of phosphorus-containing ions (Gu et al, 1993). The detection of the neutrals was performed by observing their collisional ionization.…”

Generation and characterization of ionic and neutral [HS-P-OH]+/· and S=P(OH)2+/· in the Gas Phase by Tandem Mass Spectrometry and Computational Chemistry

“…A quantitative match of the RRKM branching ratios with the product distribution in the NR mass spectra was not attempted, because it would necessitate considering also the reionization cross sections for all neutral species, their postreionization dissociations, and high-energy processes originating from excited electronic states. We note that PO · was reported to have an unusually high reionization°cross°section° [20],°which°may°contribute°to°the dominant m/z 47 peak in the NR mass spectrum.…”

“…Keck, Terlouw and their coworkers have provided NRMS experimental evidence for the gasphase existence of (methylthio) thioxophosphane (CH 3 S-P-S) [15], phosphenethiol (H 2 P-SH) [16], phosphenedithiol HP(SH) 2 [17], thioxophosphane HPS and its tautomer HSP [18] and phosphorotrithious acid P(SH) 3 [19] molecules. Gu and Tureček [20] have reported an NRMS study on several oxygenated phosphorus radicals, e.g., PO, CH 3 OPH, CH 3 OPOH, CH 3 OPOCH 3 , and (CH 3 O) 2 PO. Vivekananda, Srinivas, and coworkers reported on the generation and charac-terization of low coordinated phosphorus species, viz., CH 3 O Ϫ P ϭ O, CH 3 S Ϫ P ϭ O and NH 3 PO by using a combination of tandem mass spectrometric techniques [21,22].…”