Page 217 - Fundamentals of Air Pollution

TABLE 13-1

Collection of Gases by Absorption
Minimum
Air flow sample Collection
Gas Sampler Sorption medium (liters/m) (liters) efficiency Analysis Interferences
__
Ammonia Midget impinger 25 ml 0.1 N sulfuric 1-3 10 Nessler reagent
acid
Petri bubbler 10 ml of above 1-3 10 + 95 Nessler reagent
Benzene Glass bead column 5 ml nitrating acid 0.25 3-5 + 95 Butanone method Other aromatic
hydrocarbons
Carbon dioxide Fritted bubbler 10 ml 0.1 N barium 1 10-15 60-80 Titration with 0.05 Other acids
hydroxide N oxalic acid
Ethyl benzene Fritted bubbler or 15 ml spectrograde 1 20 + 90 Alcohol extraction, Other aromatic
midget impinger isooctane ultraviolet hydrocarbons
analysis
Formaldehyde Fritted bubbler 10 ml 1% sodium 1-3 25 + 95 Liberated sulfite Methyl ketones
bisulfite titrated, 0.01 N
iodine
Hydrochloric acid Fritted bubbler 0.005 N sodium 10 100 + 95 Titration with 0.01 Other chlorides
hydroxide N silver nitrate
Hydrogen sulfide Midget impinger 15 ml 5% cadmium 1-2 20 + 95 Add 0.05 N iodine, Mercaptans, carbon
sulfate 6 N sulfuric acid, disulfide, organic
back-titrate 0. 01 N sulfur
sodium compounds
thiosulfate
Lead, tetraethyl, Dreschel-type 100 ml 0.1M iodine 1.8-2.9 50-75 100 Dithizone Bismuth, thallium,
tetramethyl scrubber monochloride in stannous tin
0.3 N
hydrochloric acid
Mercury, diethyl and Midget impinger 15 ml of above 1.9 50-75 91-95 Same as above Same as above
dimethyl