SPARK SOURCE-MASS SPECTROMETRIC PROCEDURE EMPLOYING STABLE ISOTOPES TO STUDY UPTAKE OF COPPER BY FISH FROM SEAWATER AND FOOD

Because of the lack of suitable radioisotopes, the use of electromagnetically enriched stable isotopes as a means of studying the uptake of copper by fish (plaice) has been investigated. 65Cu (99.81 % enriched) was chosen for the tracer, while the other stable isotope 63Cu (99.88% enriched) was used as a standard spike in the spark source mass spectrometric analysis. An attractive feature of this method is that both the natural copper content of the fish organs and the concentration of added tracer are determined on the same sample by making two measurements of isotopic ratio one before and one after the addition of the standard spike. The sensitivity of the analysis is such that all but the very smallest organs of a 30-g (wet) plaice (e.g., heart, kidney, spleen) may be analyzed individually for both natural copper and the absorbed tracer. A low processing blank was achieved by the use of quartz apparatus and clean room conditions. © 1978, American Chemical Society. All rights reserved.