Resumen
This study describes the results obtained during two years of sequential sampling of wet precipitation in two sites: Mexico City and a rural area. The results indicated that the chemical constituents determined in the sequentially collected samples, decreased in ionic concentration in the early portion of the rainfall event, while it increased, decreased or remained the same during the latter part of the event. The non-parametric Mann-Whitney-Wilcoxon test when applied to data, clearly showed that there were significant differences between these two sampling sites. This study has also permitted to infer the most important scavenging mechanisms acting on the rainfall event and the possible origin of the major ions analyzed.