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 (Alll) and that obtained after field fractionation (Allf) could be large. The differences found were not statistically significant, although this may simply reflect the spread in the results. Alll/Allf had no apparent relationship with the temperature difference between the field and the lab. Although some significant correlations were found between Alll/Allf 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.