Transcript Document

Organic Sewage Tracers
•
•
Sterols are components of cells & are synthesized by most organisms
In humans cholesterol is biohydrogenated by intestinal microflora to 5b-cholestrol
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28
21
Sterol structure
18
12
19
11
3
A
4
10
5
20
17
13
C D
1
2
22
9
B
8
14
23
24
26
25
27
16
15
7
6
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Other animals also produce 5b-cholestrol but at much lower concentrations
•
Herbiverous animals produce 24-ethyl coprostanol in greater concentrations
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Assessment of Faecal Contamination Using Sterol Molecular Markers
Attenborough Ponds Nature: Long Term Effects of River Diversion
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Conneries dating
Attenborough ponds CN
Cs-137 concentration (Bq/kg)
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
0
10
1986 ?
1 sigma errors shown
20
Depth (cm)
30
40
50
60
70
80
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1963 ?
TOC vs Sterol Concentration
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Identification of Sewage Markers
Resolving co-elution
fucosterol + b-sitosterol
5b-stigmastanol
10.0
5a-cholestanol
campesterol
stigmasterol
12.5
estrone
17b-estradiol
15.0
5a-cholestane
GCounts
coprostanol
5b-epicoprostanol
Target mix
7.5
GCounts
Sediment Sample
TIC
12.5
GCounts
50
40
10.0
30
7.5
20
10
5.0
MCounts
40
2.5
MCounts
80
70
60
50
40
30
20
10
0
MCounts
125
coprostanol
30
20
m/z = 333
Cholesterol-d6
10
0
MCounts
25
20
m/z 333
15
m/z = 231
Coprostan-3-one
100
75
10
5
0
MCounts
m/z 231
100
50
75
25
5.0
50
0
MCounts
25
m/z = 329
Cholesterol
100
75
0
MCounts
200
m/z 329
150
2.5
50
100
25
50
0
0
22.2
17.5
20.0
22.5
25.0
minutes
Environment
Human Health Theme
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22.3
22.4
22.5
22.6
22.7
22.8
minutes
17.5
20.0
22.5
25.0
minutes
•Ten of eleven sewage marker
compounds were identified
in the Attenborough cores
•5a-cholestane not detected
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Sterol & Stanol Marker Pathways
R
2
R
D
HO
HO
5α- ...stanol
O
H
R=H: 5 α-cholestan-3 β-ol; ( 5 α-cholestanol); [80-97-7]
R=C H3: 5α-campestan-3β-ol ; (5α-campestanol); [ ???-??-?]
R=C2H5: 5 α-stigma stan-3β-ol; (5 α-stigmastanol); [???-??-?]
H
5α-stanone (intermediate)
R
HO
Microbial
reduction
in the natural
environment
O
O
R=H: cholest-5-en-3 β-ol; (cholesterol); [57-88-5]; mammals
Δ -stenone (intermediate)
R=CH 3 : 24 α-methyl-5-cholesten-3β-ol; (campesterol); [474-62-4]; plants
R=C2H3 : 24-ethylcholest-5-en-3 β-ol; ( β-sitosterol); [83-46-5, 19044-06-5]; plants
Δ4 -stenone (intermediate)
R
R
Intestinal
microbial
reduction
H
O
5β- ...stanol
Intestinal (5b)
R
H
R=H : 5 β-cholestan-3β-ol; (coprostanol); [360-68-9]
R=C H3 : 24-methyl-5β-cholestan-3β-ol; (5 β-c ampestanol), [ ???-??-?]
R=C2H5 : 24-ethyl-5 β-cholestan-3β-ol; (5 β-stigmastanol); [19466-47-8]
5β-stanone (intermediate)
R=H: 5β-coprostanone; [601-53-6]
Intensive microbial reworking of
faecal material in waters and
sediments in the environment
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Environmental (5a)
R
5
HO
H
D2 D
cholest-5-en-3 β-ol-d6; (cholesterol-2,2,3,4,4,6-d 6); [92543-08-3]
R
sterol
D
5β- epi...stanol
HO
H
R=H: 5β-cholestan-3α-ol; ( 5β-epicoprostanol); [516-92-7]
R=C H3: (epi-5 β-campestanol); [???-??-?]
R=C2H5: 24-ethyl-5 β-cholestan- 3α-ol; (epi- 5 β-stigmastanol); [???-??-?]
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1.
2.
3.
2
3
Sitosterol: Clifton and Church = Input from plants & or avian FM
Stigmastanol: Conneries = Input from ruminants / manure, slurry ?
Coprostanol: Concs. >0.5ug/g = received appreciable amounts of sewage
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1) Measure of sewage contamination
Cholesterol
Ratios >0.2 indicative of feacal contamination (Grimalt & Albaiges, 1990)
Coprostanol
HO
H
HO
Cholestanol
Coprostanol
HO
Coprostanol
HO
H
HO
H
H
Ratios 0.7 indicative of feacal contamination
Epicoprostanol
Epicoprostanol
Coprostanol
Coprostanol
HO
H
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Cholestanol
HO
HO
H
H
HO
H
HO
H
2) Measure of sewage treatment or age
Epicoprostanol
Ratios 0 to 0.5 sewage old or treated
Ratios 1.5 to 3 sewage fresh or untreated (Mudge etal., 1999)
Coprostanol
HO
HO
H
H
3) Combined 1 & 2
Epicoprostanol
Cholesterol
Coprostanol
HO
HO
H
Coprostanol
HO
H
H
HO
4) Other sterol markers - Terrestiral plants
Presence of sitosterol indicator of terrestrial run-off
(may indicte non-point source diffuse pollution from agricultural areas)
HO
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1.
2.
3.
Coprostanol/Cholesterol: human sewage >0.2 criteria= Only Conneries
Coprostanol/(Coprostanol+Cholestanol) human sewage >0.7= Conneries
Epicoprostanol/coprostanol:treatment or age in environ. =Church &
Clifton little sewage or high degree of treatment
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Coprostanol
Bi-plot of sewage marker compounds
1.5
1.0
High sewage,
untreated
H
0.5
HO
Epicoprostanol
HO
H
Low sewage, old or treated
0.0
0.0
0.5
1.0
1.5
2.0
2.5
Cholesterol
Coprostanol
HO
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H
HO
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•Ratio 5aCholestanol/Cholesterol:anaerobic process marker
•Conneries possible more reducing environ at 20 to 50 cm ?
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