Factors determining the concentration of nitrite in dew from Santiago, Chile

Dew was collected in Santiago City at different locations and over different surfaces. High pHs (ca 7.0) and nitrite concentrations were observed in all the samples, irrespective of the location of the sampler and the material of the collecting surface. pH of the samples correlates with sulfate, nitrate and ammonium concentrations. This parameter is the most important determinant of the amount of nitrite present in the collected dew. This suggests that transfer from the gas phase could be relevant in HONO capture. The increase in nitrite concentrations in dew collected during the period from 1995 to 2006 can be explained in terms of an increase in the average samples' pH along this period.