30 
concentration of 0,01 pCi/l, and with a 400 1 
sample one of 0.0025 pCi/l; that is - in the most 
unfavourable case, about 10 % of the values we had 
measured in seawater, Blanks, which were undertaken 
using the chemicals necessary for the chemical 
working-off of 50 1 water samples for the determi-« 
nation of 13708, gave values of 0,015 to 0.02 pCi/1l 
in 1966. 
The 90gr was determined by the well-known method 
over carbonate precipitation and nitric acid separa- 
tion. 
The radiation measurement took place, with 1low- 
level anticoincidence Beta radiation measurement 
equipment, in measurement discs of 2" diameter, 
Literature 
D.E. Schmitt and H. Kautsky (1961): 
Ein Verfahren zur Bestimmung des 1576s- 
Gehaltes im Meerwasser. 
Dt. hydrogr. Z. 27, 194. 
H.-F. Eicke (1974): 
Eine Methode zur Anreicherung und Bestimmung 
sehr geringer Gehalte von 15708 in ozeanischem 
Tiefenwasser. 
Dt. hydrogr. Z. 27, 20. 
B 2,2 Results 
All the activity concentration values obtained 
for 13708 and 90x are summarized, together with 
details of the statistical variations during the 
radiation measurement (16 probability), in the 
Tables 9 to 16.