کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
209952 | 461693 | 2014 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Characterization of Zhundong subbituminous coal by time-of-flight mass spectrometry equipped with atmospheric pressure photoionization ion source Characterization of Zhundong subbituminous coal by time-of-flight mass spectrometry equipped with atmospheric pressure photoionization ion source](/preview/png/209952.png)
Zhundong subbituminous coal pretreated with aqueous H2O2 was oxidized by aqueous NaOCl and sequentially extracted with diethyl ether (DEE) and ethyl acetate (EA) to afford DEE- and EA-extractable fractions and residue. Both extracts were esterified with CH2N2 and analyzed using high performance liquid Chromatography/mass spectrometry equipped with electrospray ionization (ESI) or atmospheric pressure photoionization (APPI) ion source. Molecular mass of 60% compounds in the esterified extracts ranged between 200 and 600 Da and more than 20% of the esterified extracts had molecular mass over 600 Da. Toluene and toluene/anisole (vol./vol. = 95/5) were used as dopants for APPI. Low- and non-polar compounds in the esterified extracts were well analyzed using APPI/MS. Compared to toluene/anisole mixture, toluene greatly increased ionization efficiency of APPI. More molecular associations were detected by ESI than by APPI. Heteroatoms were identified in most of the associated species.
• APPI was used to analyze esterified extracts from the oxidation of a Chinese coal.
• Adding toluene as dopant the greatly increased ionization efficiency of APPI
• More dimers with heteroatoms were identified with ESI/MS than with APPI/MS.
Journal: Fuel Processing Technology - Volume 117, January 2014, Pages 60–65