Gas chromatography method for petroleum hydrocarbon component

Abstract

The invention provides a gas chromatography method for petroleum hydrocarbon component, comprising the following steps: (1) unifying the scope of total petroleum hydrocarbon, that is all hydrocarbonsincluding n-hexane and n-tetraconta-carbon alkyl in a gas chromatography effluent; (2) regulating calibration substances and a calibration method, wherein total petroleum hydrocarbon (TPH) is volatilepetroleum hydrocarbon (VPH) and semi-volatile petroleum hydrocarbon (SPH), 5 n-alkanes with 6-10 carbon atoms in total are selected as a VPH calibration substance, 31 n-alkanes with 10-40 carbon atoms in total are selected as SPH calibration substances, and a calibration relationship of peak area to concentration of the calibration substances is established by an average response factorization method or a primary linear regression method; (3) quantifying all target chromatographic peaks in a sample chromatography one by one with an adjacent standard peak calibration method; (4) calculating total petroleum hydrocarbon and the petroleum hydrocarbon content of any segment.

Description

technical field [0001] The invention belongs to the field of environmental detection and relates to a gas chromatography analysis method for petroleum hydrocarbon components. Background technique [0002] Total petroleum hydrocarbons (TPH) is an important pollutant index for environmental analysis, which refers to the total content of compounds containing only two elements, carbon and hydrogen. The range of TPH is different in different countries or regions, with C 6 -C 34 、C 6 -C 35 、C 7 -C 36 、C >5 -C 35 、C 5 -C 40 and C >5 -C 44 Wait. [0003] The total petroleum hydrocarbons were detected by gas chromatography-flame ionization detector (GC-FID). In the expression of its quantitative results, it is usually expressed by the content of a certain segment including the number of carbon atoms, such as petroleum hydrocarbons (<C16 aliphatic), or expressed as TPH (C <16 ), represents the content of all substances before the peak of n-hexadecane (excludi...

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Problems solved by technology

[0005] However, the GC-FID analysis quantitative method using the TPH of the above-mentioned calibration sample has the following disadvantages: (1) the calibration standards are not uniform, and the measurement results are not comparable: when using the above-mentioned first quantitative method for the calibration sample, the quantification is based on the assumption that each group The chromatographic responses of the components are completely consistent (the peak areas corresponding to the same mass concentration of hydrocarbons are equal, which is called the chromatographic response consistency).

However, there are hundreds of components of petroleum hydrocarbons, and the chromatographic responses of each component are not completely consistent. When the laboratory uses different calibration standards, the same sample can be measured in different laboratories, and different results can be obtained, so the measurement cannot be guaranteed. Accuracy and Comparability of Results

When using the above-mentioned second quantitative method for calibrating samples, the quantification is based on the assumption that the ratio of each substance in the sample to be tested and the standard sample is the same, but if the components of petroleum hydrocarbons volatilize, biodegrade or chemically When the reaction changes, the proportional relationship among the crude petroleum hydrocarbon components will change, which will cause the measurement results to deviate; and when this quantitative method is used, the accurate information of the single component in the sample cannot be obtained; if it is necessary to obtain it, a second Measurement

(2) The GC-FID analysis and quantification method of the TPH of the calibration sample lacks an effective data processing method. The existing gas chromatograph workstation or data processing system is aimed at obtaining the quantitative results of single components and the quantification of petroleum hydrocarbons in specified sections at the same time. As a result, there is a lack of accurate methods to measure once and calculate automatically

Although the existing gas chromatograph workstation or data processing system can realize the accurate quantification of different components for a group of several GC separable single components, but for the quantitative method using several normal alkanes pure substances as standard samples, When establishing the sum-concentration correspondence of the peak areas of all substances in a certain section, the accurate quantitative information of the known single component in this section will be lost

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