Distribution of Total and Methyl Mercury in a Creek Ecosystem Near Bombay
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3
Limit of Detection and Validation
The minimum detection limit for total mercury is 2 ng (relative: 0.2 ng/ml), and
this was improved by an order of magnitude using the eus coprecipitation
technique. The minimum detection limit for methylmercury is 0.5 ng (absolute).
The efficacy of the methodology was assessed by analysis of standard reference
material obtained from IAEA (tuna fish, IAEA-350).
4
Results and Discussion
The spatial profile of the concentrations of total Hg in creek waters during the
three cruises (May 1994, October 1994 and May 1995) is shown in Fig. 2. The water
samples collected on first two cruises showed very high concentrations (0.5CONCENTRATIONS (ug/L)
5
-
-- - - -
4
3
2_ * *- ---f-- --* __
/~-- '--... - - *
- - 1:-..i:::::I_7L.--_-y.L-_----*_.L..--...J
o
_-.l: -- ~l ----.l ......L __ L -- -
-
A A 1 A2 A3 8 81 82 83 C C1 C2 C3 D D1 D2 D3
CRUISE-1:MAY 1994
*- CRUISE-3:MAY 1995
STATIONS
---+ CRUISE-2:0CT 1994
Fig. 2. Concentration of Hg in Thane Creek during three cruises (high tide)