SU918845A1 - Stationary phase for gas chromatography - Google Patents

Description

(5) STILL FOR GAS CHRESHETOGRAPHY

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This invention relates to the analysis of hydrocarbon mixtures using gas chromatography, in particular, to gas chromatographic analysis of mixtures of closely-occurring isomers of momoisopropylnaphthalenes and diisopropyl1 naphthalenes, as well as isomers of methylnororobenylxylene, boiling in the range

310-312 ° s.:

The known stationary phase is rfentilphosphinic acid, which is used for gas chromatography separation of mixtures of saturated, aromatic and nitrile compounds boiling over a wide temperature range 1.

However, the known stationary phase does not allow the separation of isomeric mixtures of mono-, diisopropyl-naphthalene, as well as a mixture of isomeric methylnororobenyl xylene. Among the known compounds used as stationary phase in gas chromatography, nor

one does not fulfill the task of separating an isomeric mixture of mono- and disubstituted isopropylnaphthalenes and isomers of methylnororonylxylene, Hexadecylphosphino is also known. 00

VA acid C.DR-OH, (GDF-acid) J21.

Hexadecylphosphinic acid is proposed as a nonto mobile phase for gas chromatographic separation and analysis of isomers of aromatic hydrocarbons.

Synth GPP-acid was carried out by oxidative chlorophosphination.

"S hexadecane by reaction Q

q.HJp - C1

Tsg M 2RS1z O C1

+ POClj HC1

0

about

20

W-S

C.N.R-C1

ib k

C1

+ .2НС1 Characteristics of the obtained compound are as follows: 09539; MRp: found 88, calculated 87.71: Found,%; C 62.41; H 11.60; R 9.82. Calculated,%: C, 62.75; And 11.44; R 10.13. The upper temperature limit for changing the specified stationary phase when working with a flame ionization detector is 250 ° C, and the lower temperature limit is compact tenper.atur. FIG. Figures 1 and 2 show chromograms with examples of using GDF-acid for gas chromatographic separation and analysis of mono (A-, (i-) and disubstituted isopropylnaphthalenes; Figures 3 and 4 are the same for separating a mixture of isomeric methylnor boricornoxylenes. Essence of gaschromatographic separation of i-, ft - and diisopropylnaphthalenes, isomers of methylnorbornylxylene, consists in using HDP-acid as a stationary phase for gas chromatographic separation of the mixture of substances. At the same time, the separation is carried out on a glass packed column (0.5 cm 4 mm), filled with spherochrome-1, fraction of 0.16-0.25 mm with impregnation of GDF-acid from its solution in benzene, in isothermal mode and during the programming of the analysis temperature. The preparation of the nozzle was carried out according to a known method. the column with the prepared packing was conditioned with temperature programming from 50 to 8–10 h, after which the mixture of mono (oL-, ft-) and diisopropylnaphthalenes and the isomeric mixture of methylnorbornyl-o-xylenes was analyzed. The efficiency of separation of closely-boiling mixtures of complex aromatic compounds on GDP-acid was compared with the results of the analysis of the same mixtures on previously obtained heptylphosphinic acid C, 12, the use of which in N OT leads to the separation of CL and (L-isopropyl naphthalene and positional isomers of methyl nororbornyl xylenes Example 1. A chromatographic analysis of a mixture of MOHod- and diisopropylnaphthalene obtained from the naphtha alkylation process was carried out on a prepared glass column (1.5 mx 4 mm) with HDF-acid at Spheochrome-1. Taline propylene. The analysis was carried out on a Tsvet-102 chromatograph with a flame ionization detector under conditions of nonlinear programming of a temperature from 50 to 50, a nitrogen carrier gas velocity of 0.54 ml / min, evaporator temperature and sample volume less than 1 µl. From the analysis results shown in the chromatogram (Fig. 1) shows that the initial separation temperature of 50 ° C corresponds to the output of nonane (solvent). Further fast programming of the temperature at a speed of 20 deg / min sets the temperature at 120 ° C at which I achieve output from naphthalene, after which the temperature is programmed at a rate of 0.5 dg / min to yield moHo-oL-, fb - «isopropylnaphthalene. As a result of the i- and fS-isopropyl naphthalene process, diisopropyl naphthalenes are formed, the separation of which is carried out by subsequent programming of the temperature to 170 ° C at a rate of 10 K / min. To compare the separation efficiency, the mixture of CL, fb, and diisopropylnaphthalenes obtained by alkylation of naphthalene with propylene was carried out under the same conditions on a glass column (1.5 mx 4 mm) with heptylphosphinic acid on spherochrome-1. From the results of the analysis presented in the chromatogram (Fig. 2), it can be seen that the separation of oL-and fb-monoisopropylnaphthalenes does not proceed at this phase, and the separation of diisopropylnaphthalenes has deteriorated significantly. EXAMPLE 2. A prepared (Example 1) nozzle on a glass column (0.5 mx 4 mm) was used to analyze the isomers of methylinorbornyl-o-xylene. The analysis was carried out in the isothermal mode at a nitrogen carrier gas velocity of 0.86 ml / min, temperature and a vaporizer of 400 ° C. The entire analysis was carried out for 1011 minutes. From the results shown in the chromatogram (Fig. 3), it can be seen that the order of release of the isomers of methylnorbornyl-o-xylene (1,3-f K 1,2-, 1,1-) corresponds to peaks 1, 2, 3,.

To compare the separation efficiency, we carried out the analysis of methylnorbornyl-o-xylene under the same conditions on a glass column (0.5 m X 4 mm) with heptylphosphinic acid on spherochrome-1.

The above chromatogram (figl) shows that the use of heptylphosphinic acid as a stationary phase leads to a total registration of the isomers of methylnorbornyl-o-xylenes at the positions of 1,3-, I, -, and 1,2-.

Thus, the use of GDP acids as a stationary phase in gas chromatography provides

POSSIBILITY of analyzing isomeric high-boiling hydrocarbon mixtures with a high degree of separation efficiency at analysis temperatures, well below the boiling points of the separated compounds, for 1020 minutes.

Claims (2)

1. USSR author's certificate If 32381, cl. G 01 N 31/08, 1970. 2. Gefter S.L. Organophosphate monomers and polymers. I., USSR Academy of Sciences, I960.