Determination of aldehydes, ketones, esters, and ethers in air using Porapak N and charcoal

Abstract

A method was developed to determine aldehydes, ketones, esters, and ethers in air which is simple, efficient, and sensitive. Analytes are trapped on a glass cartridge filled with 4 in of Porapak N followed by 1 in of charcoal. These are eluted with 1 ml of methanol, and the eluate is injected onto a gas chromatograph equipped with a photoionization detector (PID). Quantitation is performed by measuring the peak height or area of each analyte of interest and comparing it with a standard in methanol. These cartridges can be reused a number of times after reconditioning. This method is efficient since it lends itself to the use of an autosampler, which can inject large numbers of samples onto the gas chromatograph while it is unattended.

The method detection limit was from 0.6 to 16.5 μg/m³, which is comparable to other methods, and recoveries ranged from 83 to 120%. The sensitivity from highest to lowest, with respect to class of compound, was determined to be aldehydes, ketones, esters, and ethers. Up to 150 L of air can be passed onto the cartridge without any expected breakthrough of analytes, as opposed to only 10 to 30 L with 1 in of charcoal alone, which is normally the adsorbent of choice.