determination of nitrogen oxidescincentration in the atmosphere of the faculty of pharmacology,s laboratories

background: nitrogen oxides occur in the atmosphere in six forms of namely: n2o , no , no2 , n2o3, n2o4 and n2o5 .among these oxides no2 is the most important air pollutant because of its relatively high toxicity and its ubiquity in ambient air. in this research griess-saltzman method was utilized for determination of nitric oxide and nitrogen dioxide in the atmosphere of different laboratories in the faculty of pharmacology of ahwaz jondishapur university of medical science. methods:as it is reported in griess-saltzman method, no2- produce a purple color with absorbing solution containing: sulfanilic acid, glacial acetic acid and n-(1-naphtyl)-ethylenediamine dihydrochloride. the maximum wavelength absorbed by this colored solution is 550 nm. results: calibration curve was obtained in concentration range of 0.04-0.44 µg.ml-1 of no2- (eq. a= 0.9c+ 0.002 r2=0.999). between and within days mean reproducibility of the measurements were 2.2 and 1.91, respectively. nitric oxide and nitrogen dioxide concentrations in central, chemistry, hydrology, toxicology and pharmacogonosy?? labs absorbed into absorbing solution were measured from the calibration curve. conclusions: the statistical results showed that there was difference between no2 concentration at working and non working conditions of each laboratory. there was no difference between no concentration of working and non working conditions of the laboratories. also there was difference between no and no2 concentration of each laboratory. final evaluation of the results indicated that no and no2 concentrations in the faculty of pharmacy laboratories atmosphere are lower than epa reported value.