Determination of Nitrobenzenes in Ambient Air

Abstract

Analytical method of nitobenzenes in ambient air was developed. Nitrobenzenes in ambient air sample was collected into a Tenax-TA Tube, using a sucking pump at a flow rate of 1l/min. This tube was inserted into the carrier gas line of the GC/ MS equipped with a three way cock and then heated to drive off the adsorbed analytes to the analytical column at 280°C for 20min. The desorbed analytes were preconcentrated in the precolumn cooled with liquid oxygen. After thermal desorption, GC/MS analysis was performed. The recoveries for standard solution contained 200 pg each of nitrobenzene, onitrotoluene, o-/m-/p-chloronitrobenzene were 90-104% with the coefficients of variation of 4.6-10.5%. Detection limit was 0.7mg/m³ for 30l of atmospheric air sample. Breakthrough volume of tested compounds was more than 1m³. Adsorbed compounds in the Tenax-TA tube was stable in 24 days. As the result of analysis of atmospheric air samples at 14 sites in Kitakyushu City, nitrobenzene was detected in every samples. Concentration of nitrobenzene at the sampling site close to a chemical plant reacbed 230ng/m³. p-chloronitrobenzene was detected at almost all sampling sites.