Dinitrotoluene

Phototransformation in water

Administrative data

Endpoint:

phototransformation in water

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: study well documented, meets generally accepted scientific principles

Data source

Reference

Reference Type:

publication

Title:

Influence of humic substances on photolysis of nitroaromatic compounds in aqueous systems.

Author:

Simmons, M.S. and Zepp, R.G.

Year:

1986

Bibliographic source:

Wat. Res. 20, 899-904. As cited in: OECD SIDS, Dinitrotoluene (isomers mixture), CAS No.: 25321-14-6

Materials and methods

Study type:

other: direct and indirect photolysis

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Method: measured, no guideline mentioned

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,3-dinitrotoluene

EC Number:

210-013-5

EC Name:

2,3-dinitrotoluene

Cas Number:

602-01-7

Molecular formula:

C7H6N2O4

IUPAC Name:

1-methyl-2,3-dinitrobenzene

Constituent 2

Reference substance name:

2,4-dinitrotoluene

EC Number:

204-450-0

EC Name:

2,4-dinitrotoluene

Cas Number:

121-14-2

Molecular formula:

C7H6N2O4

IUPAC Name:

1-methyl-2,4-dinitrobenzene

Constituent 3

Reference substance name:

2,5-dinitrotoluene

EC Number:

210-581-4

EC Name:

2,5-dinitrotoluene

Cas Number:

619-15-8

Molecular formula:

C7H6N2O4

IUPAC Name:

2-methyl-1,4-dinitrobenzene

Constituent 4

Reference substance name:

2,6-dinitrotoluene

EC Number:

210-106-0

EC Name:

2,6-dinitrotoluene

Cas Number:

606-20-2

Molecular formula:

C7H6N2O4

IUPAC Name:

2-methyl-1,3-dinitrobenzene

Constituent 5

Reference substance name:

3,4-dinitrotoluene

EC Number:

210-222-1

EC Name:

3,4-dinitrotoluene

Cas Number:

610-39-9

Molecular formula:

C7H6N2O4

IUPAC Name:

4-methyl-1,2-dinitrobenzene

Details on test material:

- Name of test material (as cited in study report):
2,3-dinitrotoluene, CAS No. 602-01-7
2,4-dinitrotoluene, CAS No. 121-14-2
2,5-dinitrotoluene, CAS No. 619-15-8
2,6-dinitrotoluene, CAS No. 606-20-2
3,4-dinitrotoluene, CAS No. 610-39-9
- Analytical purity: no data

Study design

Radiolabelling:

no

Analytical method:

not specified

Light source:

other: Monochromatic light

Light spectrum: wavelength in nm:

313

Details on test conditions:

- Merry-go-round photoreactor
- Monochromatic light: 313 nm (2,4-DNT: potassium chromate
in potassium carbonate), 366 nm (2,6-DNT: mercury lamp)
- Concentrations: 10E-6 to 10E-5 M
- Distilled water pH 5.5
- Dark controls in each run
- Analytical monitoring

Dark controls:

yes

Results and discussion

Dissipation half-life of parent compound

DT50:

ca. 1 d

Test condition:

full exposure to sunlight; near surface conditions at latitude 40°N; averaged annual rate constants

Details on results:

Quantum yields Wavelength (nm)
2,3-DNT (7.0 +/- 1.2) x 10E-4 366
2,4-DNT (2.0 +/- 0.47) x 10E-3 313
2,5-DNT (1.0 +/- 0.16) x 10E-2 366
2,6-DNT (1.2 +/- 0.2) x 10E-3 366
3,4-DNT (7.2 +/- 1.8) x 10E-5 366

ka (per d) quantum yield (per d)
2,3-DNT 506 0.35
2,4-DNT 358 0.72
2,5-DNT 896 9.0
2,6-DNT 557 0.67
3,4-DNT 723 0.052
ka = light absorption rate.
Typical near surface ka are reported here.

Calculated photolysis half lifes: about 1 d (full exposure to sunlight; near surface conditions at latitude 40 °N, averaged annual rate constants). The presence of humic substances enhanced the sunlight induced photodegradation rates of 2,4-DNT and 2,6-DNT by an factor of 2-5 and 11-17 (compared to the results obtained with distilled water), respectively.