Mass spectrometric study of the deterioration of polystyrene-based ion-exchangers.
A mass spectrometric study of the aging effects in polystyrene-based ion-exchangers has been made. Fragments in the m/e range 10-70 were examined and attributed to OH(+), H(2)O(+), CO(+), CO(+)(2), supplemented by SO(+) and SO(+)(2) from sulphonic-acid cation-exchangers. Ion-current intensities were found to be dependent on the state of the resin.
A study of the hydrolysis of indium and lanthanum ions by partition methods
Di-(2-ethylhexyl)phosphoric acid (DEHP) in toluene and a polystyrene sulphonate type cation-exchanger have been examined for the measurement of chemical equilibrium constants for the hydrolytic reactions of very dilute aqueous solutions of indium and lanthanum at constant ionic strength, μ = 3. DEHP provides a satisfactory means of measurement for indium but not lanthanum which necessitates working at such low hydrogen ion concentrations (⩽ 10−8 M) as to cause DEHP to partially transfer to the aqueous phase. Secondary metal ion exchange by the cation-exchanger prevented a satisfactory analysis of the partition data from this source.
Identification of Dihydroxy Aromatic Compounds in a Low-Temperature Pyrolysis Coal Tar by Gas Chromatography−Mass Spectrometry (GC−MS) and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS)
Dihydroxy aromatics in coal tar undergo rapid coupling reactions with each other and with some coal-derived species during coal pyrolysis and liquefaction. However, only limited information on the structure of dihydroxy aromatics is known. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and gas chromatography−mass spectrometry (GC−MS) were used to characterize the dihydroxy aromatics in a low-temperature pyrolyzed coal tar and its distillate and residue fractions. Negative-ion electrospray ionization (ESI) FT-ICR MS spectra of coal-tar-derived samples had low molecular masses and narrow mass ranges. Negative-ion ESI is extremely selective for the dihydroxy aromatics present in coal tar. The O2 class species had the highest ion intensity among the species in the negative-ion FT-ICR mass spectrum for each sample. Dihydroxy compounds with an aromatic core structure of benzene, indan, biphenyl (and/or acenaphthene), and naphthalene were identified in the distillate fract...