Airborne contaminants sampling techniques

Petty, J.D. Gale,R.W. Huckins, J.N. Cranor, W.L. A1 varez, D. A. Clark, R.C. 2000,Development and Application of Techniques for Sampling Bioavailable Airborne Contaminants-Tentatively Identified Compounds by Gas Chromatography/Mass Spectrometry. USGS Colirmbia Environmental Research Center Colirmbia, MO Unpublished report to U.S. EPA National Exposure Assessment Laboratory Las Vegas, NV. 

Having established the need for sampling (identifi-cation/quantification of airborne contaminants) and the appropriate sampling and analysis techniques, a number of other fundamental questions need to be asked before embarking on a sampling programme ... 

Few papers on the analysis of PCAs or their measurement in environmental samples have reported on techniques to minimize contamination. PCAs (C10-C13,60-70% Cl) levels ranging from 4 ng g 1 to 25 ngg 1 in sodium sulfate were found in procedural blanks used in sediment extractions [28]. PCAs (C10-C13,60-70% Cl) were also detected in DCM (0.15 pg 1 ) left to evaporate in an open flask overnight it was unclear, however, whether contamination was a result of airborne PCAs or was from the DCM itself [28]. Similar problems have been encountered with airborne PCB contamination of analytical labs [65]. Significant procedural blanks result in higher method detection limits, i. e., the mean plus three times the standard deviation in the background signals from procedural blanks (sodium sulfate) [14,66,67]. 

Blomquist, G., Palmgren, U. and Storm, G. (1984). Improved techniques for sampling airborne fungal particles in highly contaminated environments, Scand. J. Work. Environ. Health, 10, 253-258. 

The acid digestion bomb is another powerful technique for solubilization of plastic samples, in which the digestive process is carried out in a sealed pressurized vessel called a digestion bomb and heated in a muffle furnace. The advantage of this approach is that the temperature of the process may reach well above the boiling point of the mixtures in the normal process, thus making possible the complete solubilization of some slow or incompletely dissolving components under open-vessel conditions. Volatilization of some of the analytes as well as sample contamination from airborne particulates can be also minimized. 

This technique allows determination of the weight of contaminant collected in the tube or on the diffusive monitor. When this weight is related to tile known total air volume sampled (from known pump flow rate or calculated flow rate for the passive monitor and sampling time), the average airborne concentration of the substance over the sample period can be calculated. 

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