Distribution of Acids and Neutral Nitrogen Compounds in a Chinese Crude Oil and Its Fractions: Characterized by Negative-Ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

A Chinese crude oil was distilled into multiple narrow boiling fractions. The crude oil, 39 narrow distillate fractions (up to 560 °C), and atmospheric and vacuum residues were analyzed using negative electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). The heteroatoms

Distribution of acids and nitrogen-containing compounds in biodegraded oils of the Liaohe Basin by negative ion ESI FT-ICR MS

“…O2 is the most abundant heteroatom class in our studies. This is different from the results reported by Shi et al (2010b) on a non-biodegraded oil from Liaohe Basin in which the N1 class was most abundant. This difference can be attributed to the selective removal of N1 class and/or the generation of O2 class during biodegradation.…”

“…The O2 species with DBE values of 2-7 are naphthenic acids of 1-6 naphthenic rings, which have been confirmed by GC-MS and MS using various ionization techniques (Shi et al, 2010b). The species with a DBE of 5 are likely 4-ring steroidal acids (Seifert et al, 1972;Rodrigues et al, 2000;Peters et al, 2005) and/or secohopanoic acids (Nascimento et al, 1999;Shi et al, 2010b).…”

“…Moreover, N1O4 and O5 classes were presented in asphaltenes, but absent in maltenes. Basically, these multi-heteroatom compounds are preferentially precipitated in the deasphaltene process due to their higher aromaticity and polarity that decrease their solubility in n-hexane (Chang and Fogler, 1994;Shi et al, 2010b).…”

“…The species with a DBE of 5 are likely 4-ring steroidal acids (Seifert et al, 1972;Rodrigues et al, 2000;Peters et al, 2005) and/or secohopanoic acids (Nascimento et al, 1999;Shi et al, 2010b). The species with a DBE of 6 are likely 5-ring hopanoic acids (Jaffé and Gallardo, 1993;Watson et al, 2002).…”

Molecular characterization of sulfur compounds in some specieal sulfur-rich Chinese crude oils by FT-ICR MS

“…Previous studies showed that through chemical methylation treatment, thioether, and thiophenic etc. OSCs in crude oil can be ionized for selective oxidation in the Electrospray Ionization (ESI) mode (Müller et al, 2005;Shi et al, 2010aShi et al, , 2010bPan et al, 2010;Liu et al, , 2010bLiu et al, , 2011, or in the Atmospheric Pressure Photo-Ionization (APPI) mode (Purcell et al, 2007;Liu et al, , 2010b in order to conduct FT-ICR MS analysis to characterize their distributions.…”