Method for performing soft ionization and direct mass spectrometric analysis on hydrocarbon compounds in petroleum

Abstract

The invention provides a method for performing soft ionization and direct mass spectrometric analysis on hydrocarbon compounds in petroleum. The method comprises steps as follows: a petroleum sample is subjected to soft ionization by adopting a real-time direct analysis ion source, and then direct mass spectrometric detection is performed; during soft ionization, the real-time direct analysis ion source selects a positive ion mode, carrier gas is argon, and a sampling mode is sample flow assisted sampling; the hydrocarbon compounds in petroleum are classified according to a mass spectrometric detection result, and types of the hydrocarbon compounds comprise alkane, cycloalkane and arene. According to the scheme, molecular composition distribution information of alkane, cycloalkane and arene in petroleum can be provided conveniently and deeply, so that theoretical guidance is provided for petroleum nature judgment and petroleum processing, and the method has broad application prospect in fields of petroleum extraction and processing.

Description

technical field [0001] The invention belongs to the technical field of petroleum molecular composition analysis, and in particular relates to a method for performing soft ionization direct mass spectrometry analysis on hydrocarbon compounds in petroleum. Background technique [0002] Hydrocarbons are the main components of petroleum, with a content ranging from 50% to 90%. Hydrocarbons in petroleum, including paraffins, cycloalkanes and aromatics, are widely distributed in various fractions of petroleum. Characterizing petroleum hydrocarbons and obtaining their molecular composition information will help us understand the properties of petroleum and provide guidance for rational refining of petroleum. [0003] Gas chromatography-mass spectrometry (GC-MS) is a commonly used method for characterizing the molecular composition of petroleum hydrocarbons. However, since gas chromatography requires gas phase sampling, and the boiling points of crude oil and most distillates are ...

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Problems solved by technology

This derivatization method is only suitable for a small number of hydrocarbon compounds, and the operation is complicated and time-consuming. The complicated conversion process will lead to certain deviations in the results.

Atmospheric pressure photoionization source (APPI), which can only analyze aromatic hydrocarbons in petroleum, but cannot ionize paraffins and naphthenes in petroleum

Field desorption ionization source (FI / FD) can theoretically ionize non-polar hydrocarbons, but because there is no stable method coupled with high-resolution mass spectrometry, it is not suitable for the analysis of hydrocarbons in petroleum

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