Elution of Ions from Melting Snow. Chromatographic Versus Metamorphic Mechanisms.

摘要

Columns of natural and laboratory-aged snow grains and frozen water droplets were washed with deionized distilled water and with synthetic precipitation solutions to investigate both snowpack chemical fractionation and preferential ion elution. Concentrations of Cl-, NO-3 and So2-4 in sequential fractions of the column's eluate showed no chromatographic effects, indicating that ice crystals do not possess selective affinity for inorganic anions. Consequently, preferential chemical elution previously observed in melting snow is not caused by snow acting as a chromatographic column. Additional column experiments involving elution from frozen solution drops and from aged snow showed that both fractionation and preferential elution were strongly influenced by ion exclusion during the snow crystal growth.