14 
o» 
E 
10 
C D 
IxJ 
£ 
Q 
LU 
cr 
a 
Ixl 
N 
Ixl 
Ixl 
o: 
Lx 
o 
o 
Ixl 
CO 
2nd weight 
— I st weight 
2 - 
X 100 = 50.5 t 7.5% • 
•y. 
A* • • 
• • 
/ • 
•f • 
8 
12 
16 20 
24 
28 
FIRST FREEZE DRIED WEIGHT (mg) 
Figure 5-3. First freeze-dried weight versus the second freeze- 
dried weight of Neanthes arenaceodentata samples. 
The elution efficiency (EE) of the First extraction, versus the total Cu 
present in the worms, was calculated by the following equations: 
r 
EE%= -IMxlOO 
where Cj = 
C 1M + ( C 2M ' C 2C) + ^ C 3M ' C 3C) 
an d Cy 
= Total mass of Cu 
C 1M 
= Measured Cu mass in the (A) vial 
C 2M 
= Measured Cu mass in the (B) vial 
C 3M 
= Measured Cu mass in the (C) vial 
C 2C 
= Calculated Cu mass in the (B) vial 
C 3C 
= Calculated Cu mass in the (C) vial 
The calculated EE% of Cu for this set of samples was 97.8 ± 1.8 percent. 
Therefore, lor all practical purposes of analysis for environmental samples, the 
first extraction of the worms with 5 percent HN0 3 is essentially complete for 
66 
