formation of the pyridine-analogue of 2,3,7,8-tcdd

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

Analytical behaviour of 2,3,7.8-TCDD-Py

Dioxin-like toxicity of thermal experiments

Possible practical experience 2,3,7.8-TCDD-Py

Masunaga et al. 1998

1958 1963 1968 1973 1978 1983 1988 19930

10000

20000

30000

40000

50000

60000

70000g TEQ/Jahr

PCDD/PCDF in PCPPCDD/PCDF in CNP

co-PCBOther ChlororganicsIndustrial Waste IncinerationMunicipal Waste Incineration

PCP

CNP

co-PCB

IWIIWIMWIMWI

Pesticide production, use and disposal have contributed significantly to polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) emissions in the past.

Formulation basis (FL)Active Ingredient basis (AI)

DIOXIN IMPURITIES IN PESTICIDE FORMULATIONS

0

1

10

100

1,000

10,000

100,000

Con

cent

ratio

n (n

g T

EQ

kg

-1)

Formulation basis (FL) Active Ingredient basis (AI)

Current use pesticide formulations Obsolete pesticide formulations

UNEPEmissionFactor for 2,4,5-T

Holt et al. ES&T. 44, 5409–5415 (2010)

OR

In 2,4,5-T production and in product high 2,3,7,8-TCDD level

2,4,5-Trichlorphenol (R=H)2,4,5-T (R=Essigsäure)

2,3,7,8-TCDD (Seveso-Dioxin; in Agent Orange)

ClCl

Cl

OCl Cl

O ClCl

OCl Cl

O ClCl N

NClCl

Cl ORN

Chlorpyrifos (R=Phosphor acid ester)3,5,6-trichloro-2-pyridinol (R=H)

N

Cl

Cl

O

O

N Cl

Cl

2,3,7,8-TCDD(Seveso Dioxin)

2,3,7,8-TCDD-pyridin-analogue

Cl

Cl

OR

Cl

2,4,5-Trichlorophenol (R=H)2,4,5-T (R=Acetic Acid) (in Agent Orange)

Production

Thermal Stress

Production?Thermal Stress?

Smiles Rearrangement

NCl

Cl

OR

Cl

Chlorpyrifos (R=Phosphor acid ester)3,5,6-trichloro-2-pyridinol (R=H)

NCl O

OCl

N Cl

Cl

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>







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.

Assessment:PFOA, PFXSi, PFHxSDeBDE,HBCDD,PBB, PBDD/F, HBBz, PBP, TBBPA, TBPAE, SCCP, MCCP, PCN, HCBD, OCS, PCP, PCNBPAHs, Nitro-PAHHalogenated PAHs PT-Pesticides, PT-BiocidesPT-PharmaceuticalsPT-Siloxanes Sn-Organics Hg, Cd. Pb et al.

PCDDPCDF

•PCBs•Dieldrin

Dieldrin

Aldrin

DDT

PCB

HCB

Chlordane

Heptachlor

MirexToxaphene

Endrin

“The dirty dozen”“The dirty dozen”

www.pops.int www.saicm.org www.ipen.org http://www.springerlink.com/content/0q10km8582605r1x/fulltext.pdf

“The nasty nine” alpha-, beta-, gamma-HCH, PeCB, Chlordecone, PeBDE, OBDE, HBB, PFOS

Evil Endosulfan

Litres of herbicides sprayed over 1962–1971. The data are taken from the corrected HERBS file

Stellmann et al., Nature 422, 681-687 (2003)

formation of the pyridine-analogue of 2,3,7,8-tcdd

Documents

tcdd level

consumption of chlorpyrifos

tcdd sevesodioxin

pyridinol r

t production

trichlorophenol r

trichlorphenol r

pesticide production