Method for predicting retention time of gas phase chromatogram based on macromolecule crystallization behavior derivation retention equation

A technology of retention time and gas chromatography, which is applied in the field of gas chromatography, can solve problems such as few data points, obvious deviation of retention equation, large retention time prediction error, etc.

Inactive Publication Date: 2012-01-11
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] According to research and literature retrieval, at home and abroad, three data points including the temperature and the capacity factor at the corresponding temperature of the compound are used to establish the retention equation. However, due to the lack of data points, the retention equation established by simulation deviates from the retention equation obtained by experiment. It is more obvious, which makes the prediction error of retention time too large

Method used

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  • Method for predicting retention time of gas phase chromatogram based on macromolecule crystallization behavior derivation retention equation
  • Method for predicting retention time of gas phase chromatogram based on macromolecule crystallization behavior derivation retention equation
  • Method for predicting retention time of gas phase chromatogram based on macromolecule crystallization behavior derivation retention equation

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Experimental program
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Effect test

Embodiment 1

[0112] Instruments: HP6890 gas chromatograph, hydrogen flame ionization detector, 6890 gas chromatograph workstation;

[0113] Chromatographic column: non-polar HP-5 chromatographic column (5% phenylmethyl polysiloxane, 30m × 0.32mm × 0.25μm, Agilent Technologies Co., Ltd.);

[0114] Conditions: The temperature of the detector is 250°C, and the temperature of the injection port is 250°C;

[0115] Carrier gas: use high-purity nitrogen (purity not less than 99.999%);

[0116] Injection method: split injection, the split ratio is 50:1, each injection volume is 0.2ul, and the concentration is 1μg / ml;

[0117] Constant flow operation mode: the carrier gas is at the outlet of the column, and the mass flow rate is kept constant at 1.0ml / min;

[0118] Choose from three different temperature programs, which are:

[0119] A Program temperature rise 30℃→25℃ / min→250℃

[0120] B Program temperature rise 30℃→15℃ / min→250℃

[0121] C program temperature rise 30℃→5℃ / min→250℃

[0122] (1)...

Embodiment 2

[0138] The process and condition of the present embodiment are identical with embodiment 1, and difference is:

[0139] (1) The virtual dead time τ is 1.40min;

[0140](2) Calculate the capacity factors of methanol, heptane, and isoamyl acetate at six constant temperatures of 250°C, 200°C, 150°C, 100°C, 50°C, and 30°C according to formula 13 and take the natural logarithm. The natural logarithms of the capacity factors of methanol at corresponding temperature points are: -0.868, -0.637, -0.401, -0.157, 0.141, 0.329; the natural logarithms of the capacity factors of heptane at corresponding temperature points are: -0.829, -0.573 .

[0141] (3) Make scatter diagrams of the lnk of methanol, heptane, and isoamyl acetate changing with temperature T, respectively. Three data points selected for methanol (lnk a ,T a ), (lnk b ,T b ) and (lnk c ,T c ) are (0.329, 30°C), (-0.157, 100°C) and (-0.401, 150°C); the three data points selected for heptane are (1.613, 30°C), (0.133, 1...

Embodiment 3

[0151] The process and condition of the present embodiment are identical with embodiment 1, and difference is:

[0152] (1) The virtual dead time τ is 0.90min;

[0153] (2) Calculate the capacity factors of methanol, heptane, and isoamyl acetate at six constant temperatures of 250°C, 200°C, 150°C, 100°C, 50°C and 30°C according to formula 13 and take the natural logarithm. The natural logarithms of capacity factors at corresponding temperature points are: 0.189, 0.321, 0.468, 0.634, 0.853, 1.000; ; The natural logarithms of capacity factors of isoamyl acetate at corresponding temperature points are: 0.233, 0.398, 0.649, 1.205, 2.639, 3.617.

[0154] (3) Make scatter diagrams of the lnk of methanol, heptane, and isoamyl acetate changing with temperature T, respectively. Three data points selected for methanol (lnk a ,T a ), (lnk b ,T b ) and (lnk c ,T c ) are: (1.000, 30°C), (0.634, 100°C) and (0.468, 150°C); the three data points selected for heptane are (2.124, 30°C),...

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Abstract

The invention discloses a method for predicting retention time of a gas phase chromatogram based on a macromolecule crystallization behavior derivation retention equation. The method comprises the following processes: deducing a retention equation curve which contains temperature and capacity factors based on macromolecule crystallization behavior, wherein the curve can be set up by only using three known data points which contain temperature and capacity factors of a compound at corresponding temperature; setting virtual dead time for a chromatographic column at a random temperature point according to measured retention time at a constant temperature; determining the capacity factor of the compound at the random temperature point through differentiating and integrating the whole chromatographic column according to the set retention equation curve; and predicting the retention time of the compound on the chromatographic column under a temperature-programming condition by using the data, and comparing the predicted retention time with an actually-measured value. The method for predicting the retention time of the gas phase chromatogram based on the macromolecule crystallization behavior derivation retention equation disclosed by the invention has the following advantages that: the number of adopted data points is few, and the number of experiments is reduced; the dead time has no need of measuring, and the process for predicting is simplified; and the predicting accuracy is high, and the application range is wide.

Description

technical field [0001] The invention relates to a method for predicting gas chromatography retention time by deriving a retention equation based on polymer crystallization behavior, and belongs to the technical field of gas chromatography. Background technique [0002] Gas chromatography is a very efficient technique for the separation and analysis of complex compound compositions. However, for complex components with a wide range of boiling point composition, it is usually time-consuming and labor-intensive to select appropriate temperature-programmed chromatographic separation conditions. By calculating and predicting the retention time of sample components under any programmed temperature rise conditions, it is possible to avoid blindly changing separation conditions based on experience, reduce the number of experiments, and quickly screen out the best temperature rise program, thereby realizing automatic optimization of chromatographic conditions. [0003] When people s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F19/00
Inventor 范国樑李笑玮龚彩荣
Owner TIANJIN UNIV
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