Airborne contaminants analytical techniques

In instances in which there is only a single possible contaminant in the air, no further processing of the collected material is necessary but in most cases, analysis of the collected material is necessary to separate and quantify the amounts present. NIOSH has published explicit analytical techniques to be used for a large number of airborne pollutants. For meaningful results which are legally defensible, these procedures should be followed exactly. In many cases, the commercial laboratory will provide the appropriate collector, as well as explicit instructions on... 

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]. 

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. 

It is not proposed to discuss the various techniques by which airborne concentrations of contaminants can be determined. ITiese are analytical details and the subject of prolific publications, but one outline scheme merits inclusion (Fig. 9) to illustrate the range of options available. A point worthy of comment is the increased interest in... 

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