Ammonium salts, mass

Bose AK, Pramanik BN, Bartner PL. Mass spectral studies. Part 120. Facile ionization induced by ammonium salts Mass spectra of nonvolatile compounds using unmodified electron-impact mass spectrometers. J Org Chem 1982 47 4008-4010. 

Analytical methods iaclude thin-layer chromatography (69), gas chromatography (70), and specific methods for determining amine oxides ia detergeats (71) and foods (72). Nuclear magnetic resonance (73—75) and mass spectrometry (76) have also been used. A frequentiy used procedure for iadustrial amine oxides (77) iavolves titratioa with hydrochloric acid before and after conversion of the amine to the quaternary ammonium salt by reaction with methyl iodide. A simple, rapid quaHty control procedure has been developed for the deterrniaation of amine oxide and unreacted tertiary amine (78). 

Aurin tricarboxylic acid [4431-00-9] M 422.4, m 300". The acid is dissolved in aqueous NaOH, NaHS03 solution is added until the colour is discharged and then the tricarboxylic acid is ppted with HCI [Org Synth Coll Vol I 54 1947]. Do not extract the acid with hot water because it softens forming a viscous mass. Make a solution by dissolving in aqueous NH3. See Aluminon for the ammonium salt. 

If an aqueous ammonia solution which is 0.1M is employed, the concentration of NH4 ion as ammonium chloride or other ammonium salt necessary to prevent the precipitation of magnesium hydroxide can be readily calculated as follows. Substituting in the mass action equation ... 

Veith, H.J. Field Desorption Mass Spectrometry of Quaternary Ammonium Salts Cluster Ion Formation. Org. Mass Spectrom. 1976,77,629-633. 

Veith, H.J. Mass Spectrometry of Ammonium and Iminium Salts. Mass Spectrom. Rev. 1983,2,419-446. 

Several investigators have utilized thermal techniques for the separation of sulfate species collected on filter media with subsequent analysis by electron impact mass spectrometry, wet chemical analysis or sulfur flame photometry. In most instances the separation between sulfuric acid and its ammonium salts was incomplete or problems were encountered in recovering the species of interest from filters heavily laden with particulate (29-34). 

The resulting catalyst was highly active for cyanide and acetate ion displacements on 1-bromobutane. As expected, soluble low molecular weight quaternary ammonium salts and a soluble quaternized linear poly(ethyleneimine) were even more active, presumably because they had no mass transfer and intraparticle diffusional limitations. These catalysts had a much higher density of charged sites (at least within the micro domains of the poly(ethyleneimine)) than any of the other active quaternary ammonium ion catalysts reported for nucleophilic displacement reactions. 

Derivatized polyethers such as polyether sulfate have been investigated for both positive- and negative-ion calibration [11]. Although poly ether sulfates are not commercially available, they are easily synthesized. Lauryl sulfate ethoxy-lates were also used as calibrants for negative-ion ESI. Polyether amines and quaternary ammonium salts were used as positive-ion calibration solutions [11]. These commercially available compounds do not exhibit significant sodium or potassium adducts, and they are more easily flushed out of the mass spectrometer ion source than are nonderivatized polyethers. In addition, doubly charged poly ether diamines can produce reference peaks at low m/z values. 

Specific examples illustrate that similar principles affect the absorption spectra. For example, as we have pointed out above, the neutral form of the C-2 benzyl ester is red in MeOH and orange in methylene chloride. Thus it has the spectrum of the ionized form in the polar, protic solvent and of the nonionized form in the nonpolar solvent methylene chloride [248]. The tributyl ammonium salt of the C-2 octyl ester is soluble in solvents ranging from ethanol-water to toluene. Its spectrum in an essentially nonionizing solvent such as toluene is that of the ionized xanthene [249], The spectrum of the pyrillium salt in ethanol is concentration dependent. In dilute solution the compound is totally ionized and is red, whereas in concentrated solution the compound is not fully ionized and the orange form predominates, as predicted by the law of mass action. 

Other aspects of the report (42) on [Fe3S2(NO)5] are surprising. Elemental analysis of the ammonium salt was reported to distinguish between iron(II) and iron(III) in [Fe3S2(NO)5] , but to find these two types of iron present in equal numbers is most unusual for a triiron complex. Second, the molecular weight of the potassium salt was measured as 420 by mass spectrometry. This value is close to the M/Z of 421 calculated for the most abundant isotopic form of the ion-pair cation [KFe3S2(NO)5] +. Finally, the ESR spectrum reported is that of a dini-trosyliron species, which bears a remarkable resemblance to that reported (22) for a complex formed from Fe(II) and nitric oxide in aqueous alkaline solution. 

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