Determination of field ionization relative ion sensitivities in mass spectrometry of coal-derived oil components

The Coupling of Supercritical Fluid Chromatography and Field Ionization Time-of-Flight High-Resolution Mass Spectrometry for Rapid and Quantitative Analysis of Petroleum Middle Distillates

“…Figure 4 shows that FI molar sensitivity increases sharply with the carbon number, which is consistent with published works. 36,37 Replicate analyses (five times) showed the average relative standard deviation (RSD) of FIMS measurements to be 7.8%. UV chromatogram can be conveniently used to define the split point between saturates and various aromatic ring types.…”

Determination of hydrocarbon composition in high-boiling and nondistillable coal liquids by liquid chromatography/field ionization mass spectrometry

“…however, differ by the number of double bonds-0, 5, 6, and 12, respectively. The HPLC/FIMS separation and characterization method developed allows for determination of each of the four compounds, because each would be present in a different "double bond" fraction.…”

“…RESULT AND DISCUSSION General Consideration. FIMS produces virtually frgment-ion-free mass spectra (19) and is ideally suited to the analysis of components in coal-derived liquids (11,12,18,(20)(21)(22)(23)(24)(25). However, the dependence of sensitivity coefficients on molecular structure and weight and also on the mixture composition does not allow one to obtain fully quantitative data from FI mass spectra.…”

“…Determination of sensitivity coefficients is precluded, however, by the unavailability of many of the model compounds expected or known to be present in coalderived products and by the complexity of heavy coal liquids in particular. Very recently, Yoshida et al (11,12) reported results on FI relative ion sensitivities obtained on components actually separated from coal-derived liquids by liquid chromatography. They found that (1) the relative ion sensitivities of compounds in a Z series increase exponentially with the composite length of alkyl side chains, (2) the effect of alkyl side chain increases with the increase in the size of the aromatic ring system, and finally (3) the effect of alkyl side chains decreases with the decrease in Z value, as the aromatic ring system approaches hydroaromatic structures.…”

Comparison of hydrocarbon composition in complex coal-liquid samples by liquid chromatography and field-ionization mass spectroscopy

“…After correction of individual intensity values in the FI mass spectrum for natural abundance of 13C, it was possible to convert the individual relative intensity values in each double bond fraction to weight percent in the coal-liquid sample. The weight percent values can be calculated by using eq 4, a form of which was recently reported by Yoshida et al (22) wt %; = Wt%total MJi Li(MiIi) (4) where wt%; is the weight percent of the ¿th component, wt% ^is the weight percent of the double bond fraction in the coal-liquid sample, and M¡ and 7¡ are as before. However, eq 4 is awkward to use in that the term ,( ;7;) is tedious to calculate.…”