Transcript Kein Folientitel - Max Planck Institute for Biogeochemistry

Determination of Al, Cd, Cr, Cu, Fe,
Mn, Ni and Zn in woodlice and their
skins – Is moulting a means of
decontamination?
Michael Raessler, Jan Rothe and Ines Hilke
Max-Planck-Institut fuer Biogeochemie, Hans-Knoell-Strasse 10,
D-07745 Jena, Germany
Why analyzing woodlice and their
skins?
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They are:
good bioindicators;
widespread throughout rural and urban areas in
Central Europe;
relatively large, conspicous and easily collected;
show a high tolerance for heavy metals;
accumulate heavy metals efficiently in their
hepatopancreas;
can be reared under standardized conditions;
Sample preparation
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Woodlice were cultivated under standardized conditions
in a climatic chamber at T= 22°C and a humidity of >
90%
Animals were fed with carrots and lettuce from the same
supplier; no additional water was provided
The density of the population was regularly checked to
avoid trophic enrichment of minerals by cannibalism
After 1 year, 15 animals (30 – 40 mg dry weight) per
species of the same age and size were picked out
manually
Animals were killed by cooling to – 18°C
Animals were freeze-dried, pooled and ground
Skin of Animals
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Separately and manually collected after moulting
every 2 – 3 weeks
Pooled samples from 6 months of skin collection
were dried and ground
Subsamples of 50 mg (10 – 12 skins of adult
woodlice) were used for digestion and analysis
Sample Digestion
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Microwave-assisted high pressure digestion
(Multiwave, Anton Paar, Graz, Austria)
Sample weight: 100 mg (woodlice and
reference material)
50 mg (skin samples)
3 mL nitric acid (HNO3), 65%, suprapur
(Merck, Damrstadt, Germany)
A blank was run with each series to check for
possible contamination of reagents and vessels
Digested samples were transferred to 50 mL
glass vessels for analysis by ICP-OES
Reference Materials
Dorm-2, Dogfish muscle (Squalus acanthias)
SRM 1577b, BOVINE LIVER
were selected to respond the following requests:
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To match the animal matrix as closely as possible
To contain the elements under consideration in a
concentration range which was both expected in the
animals and also accessible to ICP-OES after digestion
and dilution
To contain certain elements in both standards for double
control (Cu, Fe, Mn, Zn)
Analysis by ICP-OES (1)
RF power
Plasma Gas
Auxiliary Gas
Nebulizer Gas
Pump Rate
Nebulizer
Spray Chamber
Plasma View
Viewing Distance
1300 watts
15 L/min
0,5 L/min
0,8 L/min
1,3 L/min
Cross-flow
Scott-type, Ryton
Axial
15 mm
Optima 3300 DV, Perkin Elmer, Norwalk, CT, USA
Analysis by ICP-OES (2)
Element
Al
Cd
Cr
Cu
Fe
Mn
Ni
Zn
WL [nm] LOD
[µg/L]
396,152
0,8
226,502
0,4
267,716
0,4
224,700
1,0
259,940
0,3
259,372
0,1
231,604
0,8
213,857
0,5
LOQa
[µg/kg]
400
200
200
500
150
50
400
250
Results of Dorm-2
Element Certified
Tolerance
Concentration [mg/kg]
[mg/kg]
Al
10,9
1,7
Cr
34,7
5,5
Cu
2,34
0,16
Analysis SD
[mg/kg] [mg/kg]
12,1
29,6
2,32
0,9
1
0,23
Fe
Mn
Ni
142
3,66
19,4
10
0,34
3,1
135,9
4,01
19,5
5
0,18
0,3
Zn
25,6
2,3
26,6
0,4
Results of Bovine Liver
Element
Cd
Certified
Tolerance
Concentration [mg/kg]
[mg/kg]
0,50
0,03
Analysis SD
[mg/kg] [mg/kg]
0,51
0,02
Cu
160
8
163
1
Fe
184
15
187
3
Mn
Zn
10,5
127
1,7
16
10,7
127
0,2
2
Analyses of P. scaber and their
Skins
Element
Al
Cd
Animal
SD [mg/kg]
[mg/kg]
229
0,5
2,58
0,04
Cr
Cu
Fe
2,02
171
249
Mn
Ni
Zn
77,6
4,02
170
Skins
SD
[mg/kg] [mg/kg]
631
6,4
< 0,2
0,08
2,8
1,4
3,04
8,4
502
0,2
0,1
2,1
0,4
0,4
0,8
142
9,9
28,2
0,8
0,8
1,1
Analyses of P. dilatatus and their
Skins
Element
Animal
SD
[mg/kg] [mg/kg]
Al
Cd
621
0,99
Cr
4,63
Cu
Fe
Mn
Ni
Zn
116
642
77
4,16
97,6
2,1
0,06
Skins
SD
[mg/kg] [mg/kg]
922
< 0,2
6,3
0,1
13,8
0,6
2,8
7,1
1,4
9,1
969
125
0,8
7,0
1,3
0,1
0,5
28,3
32,3
1,5
0,5
Comparison of P. scaber and P.
dilatatus
6
4.5
P. scaber
P. dilatatus
3
1.5
0
Al
Cr Fe Mn Ni
Conclusions
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Enrichment in skins for Al, Cr, Fe, Mn and Ni
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No enrichment in skins observed for Cd, Cu and Zn
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Moulting is a possible means of decontamination in
both P. scaber and P. dilatatatus for Al, Cr, Fe, Mn
and Ni, but not for Cd, Cu and Zn
Acknowledgement
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Many thanks
to Silja Ursel and Kristin Lober, FSU
Jena
And to all