HIGHLY DISPERSED SILICIC-ACID AS A TRACE COLLECTOR FOR MULTI-ELEMENT PRECONCENTRATION

Highly dispersed silicic acid as a trace collector for multi-element preconcentration. The purity and sorption properties of commercially available, highly dispersed silicic acid are investigated and compared with those of pure activated carbon for use as trace collectors. For a series of elements, the blanks and their fluctuations caused by silicic acid are significantly smaller, so that detection limits are improved. Activated carbon, however, is the better adsorbent for preconcentration of chelate complexes; in general, recoveries are much higher than are obtainable under similar conditions with the silicic acid. As examples of the applicability of hydrophobic silicic acid as a trace collector, about ten trace elements are preconcentrated from the pure aluminium, gallium and magnesium metals. © 1979.