TY - JOUR

T1 - Газохроматографическое определение неполярных примесей в этаноле и ацетоне с использованием заполненного оксидом алюминия вкладыша в инжекторе

AU - Zhuravleva, G. A.

AU - Rodinkov, O. V.

N1 - Funding Information: Current study was supported by RFFI grant № 16-33-60099 mol_a_dk. Publisher Copyright: © 2018 Ural Federal University. All rights reserved. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2018

Y1 - 2018

N2 - Gas chromatographic determination of impurities in organic solvents is complicated by the presence of a wide solvent peak on the chromatogram that can overlap with the peaks of the analytes. Especially difficult is the determination of analytes that are held in the gas chromatography column stronger than the main component since the peak of the latter usually has an elongated tail. The purpose of this paper is to evaluate the analytical capabilities of the gas chromatographic determination of nonpolar impurities in polar solvents with the selective solvent retention using a liner filled with a high-polar sorbent. We have a priori evaluated the possibility of using highly polar adsorbents, such as zeolites, silica gels and aluminum oxide, which are most common in gas chromatography for the retention of polar solvent vapors. Zeolites had to be rejected due to a high temperature requirement for their regeneration. In contrast to silica gel (silicon dioxide), aluminum oxide, along with the specific molecular adsorption, is also capable of strong chemisorption of polar and, above all, oxygen-containing organic compounds. Since the latter circumstance should promote stronger retention of these compounds over a wide temperature range, a preference is given to an aluminum oxide. Aluminum oxide as an adsorbent has several advantages: thermal stability and ease of regeneration, high mechanical strength and low cost. A scheme for gas chromatographic determination of nonpolar impurities (aliphatic and aromatic hydrocarbons) in polar solvents (ethanol, acetone) based on the selective retention of solvents in a liner filled with aluminum oxide is proposed. A group of low boiling polar organic compounds having a sufficiently high affinity for aluminum oxide and a group of nonpolar compounds that are practically not retained on this sorbent have been established. The affiliation of a compound to a particular group is determined by its dielectric permittivity. The analytical possibilities of the proposed scheme is investigated using standard solutions of aliphatic and aromatic hydrocarbons in ethanol and acetone. The possibility of increasing the repeatability and repeatedly decreasing the detection limits of analytes having retention parameters close to the retention parameters of the main component at the capillary column selected for separation is shown. At the same time, the metrological characteristics for the other components change insignificantly. The possibilities of the proposed scheme of analysis are also illustrated by chromatograms of separation of solutions containing a micro impurity of gasoline in ethanol and acetone.

AB - Gas chromatographic determination of impurities in organic solvents is complicated by the presence of a wide solvent peak on the chromatogram that can overlap with the peaks of the analytes. Especially difficult is the determination of analytes that are held in the gas chromatography column stronger than the main component since the peak of the latter usually has an elongated tail. The purpose of this paper is to evaluate the analytical capabilities of the gas chromatographic determination of nonpolar impurities in polar solvents with the selective solvent retention using a liner filled with a high-polar sorbent. We have a priori evaluated the possibility of using highly polar adsorbents, such as zeolites, silica gels and aluminum oxide, which are most common in gas chromatography for the retention of polar solvent vapors. Zeolites had to be rejected due to a high temperature requirement for their regeneration. In contrast to silica gel (silicon dioxide), aluminum oxide, along with the specific molecular adsorption, is also capable of strong chemisorption of polar and, above all, oxygen-containing organic compounds. Since the latter circumstance should promote stronger retention of these compounds over a wide temperature range, a preference is given to an aluminum oxide. Aluminum oxide as an adsorbent has several advantages: thermal stability and ease of regeneration, high mechanical strength and low cost. A scheme for gas chromatographic determination of nonpolar impurities (aliphatic and aromatic hydrocarbons) in polar solvents (ethanol, acetone) based on the selective retention of solvents in a liner filled with aluminum oxide is proposed. A group of low boiling polar organic compounds having a sufficiently high affinity for aluminum oxide and a group of nonpolar compounds that are practically not retained on this sorbent have been established. The affiliation of a compound to a particular group is determined by its dielectric permittivity. The analytical possibilities of the proposed scheme is investigated using standard solutions of aliphatic and aromatic hydrocarbons in ethanol and acetone. The possibility of increasing the repeatability and repeatedly decreasing the detection limits of analytes having retention parameters close to the retention parameters of the main component at the capillary column selected for separation is shown. At the same time, the metrological characteristics for the other components change insignificantly. The possibilities of the proposed scheme of analysis are also illustrated by chromatograms of separation of solutions containing a micro impurity of gasoline in ethanol and acetone.

KW - Acetone

KW - Aluminum oxide

KW - Analysis

KW - Capillary chromatography

KW - Determination

KW - Ethanol

KW - Gas

KW - Liner

KW - Nonpolar impurities

KW - Polar solvents

UR - http://www.scopus.com/inward/record.url?scp=85102530732&partnerID=8YFLogxK

U2 - 10.15826/analitika.2018.22.3.007

DO - 10.15826/analitika.2018.22.3.007

M3 - статья

AN - SCOPUS:85102530732

VL - 22

SP - 267

EP - 272

JO - АНАЛИТИКА И КОНТРОЛЬ

JF - АНАЛИТИКА И КОНТРОЛЬ

SN - 2073-1442

IS - 3

ER -