Aluminium fractionation using cation exchange:: comparison of results obtained after fractionation in the field and in the laboratory

Abstract

Dissolved aluminium was fractionated in the field and the laboratory using a cation-exchange method. Although absolute differences between results obtained from field and laboratory fractionations were generally small, relative differences, expressed as the ratio between labile aluminium determined after laboratory fractionation (Al-ll) and that obtained after field fractionation (Al-lf) could be large. The differences found were not statistically significant, although this may simply reflect the spread in the results. Al-ll/Al-lf had no apparent relationship with the temperature difference between the field and the lab. Although some significant correlations were found between Al-ll/Al-lf and H+, no significant correlations were found with the equivalent relative difference in {H+} between the lab and the field; nor was any significant correlation found with dissolved organic carbon.