Sakiyama T 1 , Weber R 2 *, Behnisch P 3 , Nakano T 4 1 Osaka City Institute of Public Health and Env. Sciences, Tohjo- cho 8-34, Tennoji-ku, Osaka 543-0026, Japan; 2 POPs Environmental Consulting, Ulmenstrasse 3, 73035 Göppingen, Germany 3 BioDetection Systems BV (BDS), Kruislaan 406, 1098 SM Amsterdam, The Netherlands, 4 Osaka University, Research Center for Environm. Preservation 2-5 Yamadaoka, Suita, Osaka 565-0871, Japan
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FORMATION OF THE PYRIDINE-ANALOGUE OF 2,3,7,8-TCDD
FORMATION OF THE PYRIDINE-ANALOGUE OF 2,3,7,8-TCDD. BY THERMAL TREATMENT OF CHLORPYRIFOS, CHLORPYRIFOS-METHYL AND THEIR MAJOR DEGRADATION PRODUCT 3,5,6-TRICHLORO-2-PYRIDINOL. Sakiyama T 1 , Weber R 2 *, Behnisch P 3 , Nakano T 4 - PowerPoint PPT Presentation
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Sakiyama T1, Weber R2*, Behnisch P3, Nakano T4
1Osaka City Institute of Public Health and Env. Sciences, Tohjo-cho 8-34, Tennoji-ku, Osaka 543-0026, Japan; 2 POPs Environmental Consulting, Ulmenstrasse 3, 73035 Göppingen, Germany3BioDetection Systems BV (BDS), Kruislaan 406, 1098 SM Amsterdam, The Netherlands, 4Osaka University, Research Center for Environm. Preservation 2-5 Yamadaoka, Suita, Osaka 565-0871, Japan
Dioxins and pesticide history Japan
Dioxin and pesticide screening Australia (2010)
2,4,5-T and chlorpyrifos as Twins?
Chlorpyrifos as
Formation of Pyridin analogue 2,3,7.8-TCDD in thermal experiments
Pesticide production, use and disposal have contributed significantly to polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) emissions in the past.
Highest sales of chlorpyrifos of all organophosphate pesticides worldwide, and the third among all pesticides.
In 2010, the consumption of chlorpyrifos globally (converted into technical) reached 80,000 tonnes with CAGR of about 12% in the past five years (2005 to 2010).
Chinese production capacity was 116,000 tonnes (2010).
Chlorpyrifos Chlorpyrifos-Methyl
In Vietnam about 37,000 tonnes of 2,4,5-T have been sprayed in total containing 366 kg TEQ to 1123 kg TEQ (Stellmann et al., Nature 422, 681-687 (2003)
All pyrolysis experiments were carried out in sealed brown glass ampoules (10 ml; air) with about 2 mg of respective chemical chlorpyrifos, chlorpyrifos-methyl and the major degradation product of chlorpyrifos, 3,5,6-trichloro-2-pyridinol (TCPy) at temperatures between 300ºC and 380ºC.
Chlorpyrifos Chlorpyrifos-Methyl
Analytical grade chlorpyrifos, TCPy (both Dr. Ehrenstorfer GmbH, Augsburg/Germany) and chlorpyrifos-methyl (Wako Pure Chemicals, Osaka/Japan) were used.
Relative abundance of 2,3,7,8-TCDD-pyridine-analogues formed in thermal experiments (ampoule; air;15 min)
2378-TCDD-pyridine-analogue (1)*
2378-TCDD-pyridine-analogue (2)**
300ºC 340ºC 380ºC 300ºC 340ºC 380ºC
chlorpyrifos 0 0 1x10^5 0 0 3x10^5
chlorpyrifos-methyl
0 0 6x10^5 0 0 3x10^6
3,5,6-trichloro-2-pyridinol
1x10^5 6x10^6 3x10^7 1x10^5 1x10^7 1x10^8
*trans-isomer of 2,3,7,8-TCDD-Py; **cis-isomer of 2,3,7,8-TCDD-Py
①
Peak ①& Peak ③
②
③
④⑤
Peak ②& Peak ④
Peak ⑤
①
Peak ①& Peak ③
②
③
④⑤
Peak ②& Peak ④
Peak ⑤
N
Cl
Cl
Cl
H
N
Cl
Cl
Cl
HO
N
Cl
Cl
Cl
H
N
Cl
Cl
HO
N
Cl
Cl
Cl
H
O
N
Cl
Cl
O
O
N Cl
Cl
1,3,6,8-
13C12 labeled TeCDDs(m/z:333.9338)
1,2,3,4-2,3,7,8-
TeCDDs in Flyash(m/z:321.8937)
2,3,7,8- TeCDD-N Analogues from TCPy pyrolysis (m/z:323.8841)
1,3,6,8-
13C12 labeled TeCDDs(m/z:333.9338)
1,2,3,4-2,3,7,8-
TeCDDs in Flyash(m/z:321.8937)
2,3,7,8- TeCDD-N Analogues from TCPy pyrolysis (m/z:323.8841)
15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5minutes
0.0
0.5
1.0
MCounts
0.00.51.01.52.0
MCounts
0
200
400
600
kCounts
0.000.250.500.751.00
MCounts
0
20
40
60MCounts
0
25
50
75MCounts
0.00.51.01.5
MCounts
piridinol-380C-10mi.XMS 254.0> Filtered254.0>
piridinol-380C-10mi.XMS 256.0> Filtered256.0>
piridinol-380C-10mi.XMS 288.0> Filtered288.0>
piridinol-380C-10mi.XMS 290.0> Filtered290.0>
piridinol-380C-10mi.XMS 322.0> Filtered322.0>
piridinol-380C-10mi.XMS 324.0> Filtered324.0>
piridinol-380C-10mi.XMS 358.0> Filtered358.0>
2,3,7,8-TCDD- N-analogues
TriCDD N-analogue
TriCDD N-analogues
DiCDD N-analogue
DiCDD N-analogue
2,3,7,8-TCDD N-analogues
PentaCDD N-analogue
The 2,3,7,8-TCDD-Py does not elute gogether with PCDD/PCDF in the following clean-up columns: (mention which columns
The Pyridin-analogues as base are adsorbed on the column and need specific elution in the clean-up
Therefore PCDD-Py are not transfered to GC/MS with (most?) current clean-up columns and would therefore not be detected in GC/MS (even in scan mode).
Dioxin-like toxicities were assessed with the DR-CALUXTM assay.
Extremely high dioxin-like toxicity was detected from the treatment at 380ºC of TCPy (143,000 ng 2,3,7,8-TCDD bio-TEQ/g treated TCPy).
The 48 h kinetic indicated that the dioxin-like active compounds were stable.
DR CALUX, 24 and 48 hours exposure
-1 0 1 2 30
50
100
150TCDD, 24 h
TCDD, 48 h
[TCDD] (log M)
% M
ax T
CD
D R
esp
on
se
DR CALUX, 24 hours exposure
-10 -8 -6 -4 -2 00
50
100
150Chlorpyrifos, 380 CCl-piridinol, 380 CCl-piridinol, 340 C
Log dilution
% M
ax T
CD
D R
esp
on
se
DR CALUX, 48 hours exposure
-8 -6 -4 -2 00
50
100
150Chlorpyrifos, 380 CCl-piridinol, 380 CCl-piridinol, 340 C
Log dilution
% M
ax T
CD
D R
esp
on
se
2,3,7,8-TCDD-Py (having dioxin-like toxicity) is formed from chlorpyrifos, chlorpyrifos-methyl and in particular their major degradation product (TCPy) in heating experiments highlighting the need to investigate the formation of 2,3,7,8-TCDD-Py in real world scenarios with thermal stress e.g.
cigarette smoking (chlorpyrifos used in tobacco cultivation)
the combustion of post-harvest residues
fires in pesticide production or storage.
Furthermore, 2,3,7,8-TCDD-Py is a high volume pesticide used for e.g. should be screened in chlorpyrifos pesticide formulations. With the background that 2,4,5-TCP based pesticides (Agent Orange, Pink, Purpule, White contained extreme high 2,3,7,8-TCDD levels).
Such assessments should include bio-assays for quantitative toxicity information on the extent of dioxin-like activity considering that also compounds other then 2,3,7,8-TCDD-Py seem to have dioxin-like activity in thermal treatment of chlorpyrifos.