Retention indices in gas chromatography with linear programming of carrier gas pressure (flow rate)

The development of physicochemical methods for the analysis of objects of complex composition requires the application of methods of mathematical experiment design. This article investigates the possibility of using probabilistic-deterministic design of experiment (PDDoE) for obtaining a mathematical model of the chromatographic separation process of coal tar hydrogenation products on an Agilent 7890A device with an Rxi-5ms column. It is shown that the relationship between the column heating rate and the carrier gas pressure with the values averaged for the entire chromatogram can be established with a high accuracy. It is noted that the accuracy of modeling the individual characteristics of the mixture components’ peaks is less, but remains sufficient for many practical needs. Nonlinear multiple correlation coefficients (NMC) for the dependence of the average retention time and average intensity on the considered factors are more than 0.99; they are more than 0.98 for the average peak width. NMC for the dependence of the resolution with the relation to the peaks of naphthalene and 2-ethylphenol is more than 0.8 at a significant level that sufficient for practice. The quality of the mathematical model was checked by triple registration of the chromatogram at the values of the column heating rate and carrier gas pressure that were not used in the training experiment. The measurement results are excellent squared with those calculated using the obtained generalized equations. The PDDoE method can be recommended as a method for mathematical design of an optimization experiment in gas chromatography.

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A simple restrictor for controlling carrier gas flow rate in gas chromatography

Journal of High Resolution Chromatography ◽

10.1002/jhrc.1240020406 ◽

1979 ◽

Vol 2 (4) ◽

pp. 186-186 ◽

Cited By ~ 5

Author(s):

V. Pretorius

Keyword(s):

Gas Chromatography ◽

Flow Rate ◽

Gas Flow ◽

Gas Flow Rate ◽

Carrier Gas ◽

Carrier Gas Flow

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Establishment of Gas Chromatography Analytical Method for 4-Amino-2-Methylpentane

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.865.624 ◽

2017 ◽

Vol 865 ◽

pp. 624-629

Author(s):

Shu Chun Zhao ◽

Yan Yan Yan ◽

Yue Zhang ◽

Xin Rui Dong ◽

Hua Zhao ◽

...

Keyword(s):

Gas Chromatography ◽

Flow Rate ◽

Gas Flow ◽

Gas Flow Rate ◽

Pure Nitrogen ◽

Column Temperature ◽

Carrier Gas ◽

Flame Ionization ◽

Split Ratio ◽

Accuracy And Precision

The aim of this paper was to establish a gas chromatography (GC) method for the determination of 4-amino-2-methylpentane and validate the methodology. The gas chromatography conditions such as column temperature, carrier gas flow rate, split ratio and the make-up gas flow rate were investigated in detail. The chromatographic column used in this method was capillary column of DA-1. The oven temperature was initially held at 40 °C for 15 min and was then programmed temperature to 140 °C at the rate of 75 °C/min and held for 10 min. The injection temperature was 180 °C and the flame ionization detector temperature was 200 °C. The carrier gas was high pure nitrogen with a flow rate of 0.8 mL/min. The split ratio was 130:1 and the make-up gas flow rate was 30 mL/min. Good linearity of 4-amino-2-methylpentane was obtained within the concentration range of 25.44 mg/mL to 84.81 mg/mL and the correlation coefficient was 0.9990. Good accuracy and precision were obtained and the average recovery was 101.76%. The quantification limit of 4-amino-2-methylpentane was 7.21 μg/mL and the detection limit of that was 3.72 μg/mL. The method was well-validated and proved to be used for quality test of 4-amino-2-methylpentane.

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