COMPARATIVE STUDY OF CANISTER AND SORBENT TUBE SAMPLING OF ORGANIC COMPOUNDS AND THEIR WORLD WIDE STATUS

ABSTRACT

The demand for accurate, reliable and sensitive techniques for monitoring trace levels of VOC (volatile organic compounds) has always been a topic for further research and improvement due to their volatility and their small concentration in ambient air. Two rugged semi-automatic devices for tube thermal desorption and SUMMA canister analyses, both equipped with identical cryofocusing units, were connected simultaneously to a gas chromatograph-mass spectrometer in tandem. For both systems, the same VOCOL capillary column was used for separation of collected VOCs, thus enabling the maintenance of identical chromatographic and mass spectrometric conditions. This unique arrangement allows the comparison of various parameters, the most important being the methods detection limits. For the majority of experiments, a commercial mixture containing three kinds of dichloroethylenes, tri- and tetrachloroethylene, benzene, toluene, ethyl benzene and xylene in nitrogen was used. Standard deviation, relative standard deviation and confidence interval calculations were carried out for the precision assessment of the method. The levels of various organic compounds (aromatic as well as aliphatic) along with the methodology used, in major cities of the world, are compiled to make one quick understanding of the world-wide status. This paper makes a sincere effort in providing precision assessment of the methods for trace level monitoring of VOCs and their global scenario.

	COMPARATIVE STUDY OF CANISTER AND SORBENT TUBE SAMPLING OF ORGANIC COMPOUNDS AND THEIR WORLD WIDE STATUS [.doc, 217.6Kb]
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