A Simple Method for Preparing Accurate Standard Gas Mixtures of Volatile Substances at Low Concentration Levels

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 4 Issue 4 (1999) pp 141-143

A Simple Method for Preparing Accurate Standard Gas Mixtures of Volatile Substances at Low Concentration Levels

A. Uyanik* and N. Tinkiliç

Ondokuz Mayis University, 55139 Kurupelit, Samsun, Turkey

Published online: 2 August 1999

Abstract. A simple approach for preparing standard gas mixtures of environmentally important volatile organic substances for gas chromatographic calibration is described. A liquid solution of the volatile substance of interest in a suitable solvent is prepared in a flask at known low concentration. Then, an easily measurable volume of this solution containing a very minute amount of the analyte is injected into a fixed-volume vessel (e.g., a glass sampling bulb) that has been flushed with a dilutent gas (e.g., air, N2, He). The generated gas-phase concentration of the substance after evaporation is easily calculated. This method allows students to prepare standard gas-phase mixtures at very low concentrations by direct injection of extremely small amounts into solution using a reasonable size microsyringe.

Key Words: Laboratories and Demonstrations; gas mixtures; calibration; chromatography

(*) Corresponding author. (E-mail: samsun.omu.edu.tr )

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