1,3,4-Thiadiazole-2(3H)-thione, 5-(tert-dodecyldithio)-

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2012-04-16 - 2012-06-13

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP guideline study on supporting substance. This result is read-across from ‘1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-nonanethiol’. Read-across is justified as the two substances ‘1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-dodecanethiol’ and ‘1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-nonanethiol’ are virtually the same: the only difference between those two UVCB substances is that one of the used raw materials (alkanethiol) has a diversity in the C-range, i.e. on the one hand a tert. C12-alkanethiol is used in the manufacturing process, on the other hand a tert. C9. Hence, based on the (structural) similarity of both substances it is safe to say that the physicochemical, toxicological and ecotoxicological properties are likely to be similar.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of The United Kingdom

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Test material

Test material information

Constituent 1

Reference substance name:

1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-nonanethiol

EC Number:

293-927-7

EC Name:

1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-nonanethiol

Cas Number:

91648-65-6

Molecular formula:

not applicable (UVCB substance)

IUPAC Name:

1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-nonanethiol

Test material form:

other: liquid

Details on test material:

- Name of test material: 1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-nonanethiol
- Physical state: Amber colored liquid
- Expiry Date: 2013-09-05
- Storage condition of test material: Room temperature in the dark

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No surrogate or analogue material was used.

Study design

Test temperature:

30 °C (column temperature)

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Agilent Technologies 1100, incorporating autosampler and workstation
- Type: Cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties
- Type and dimension of analytical column: Luna 5 µ CN (150 x 4.6 mm id)
- Detection system: UV

MOBILE PHASES
- Type: Methanol:water (55:45 v/v) [The mobile phase was altered to 100 % methanol after DDT to elute the highly retained test substance.]
- pH: 7.3

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column

REFERENCE SUBSTANCES
- Identity: 133 mg/L Acetanilide, 139 mg/L Phenol, 116 mg/L Atrazine, 108 mg/L Isoproturon, 120 mg/L Triadimenol, 89 Linuron, 135 mg/L Naphthalene, 157 mg/L Endosulfan-diol, 163 mg/L Fenthion, 98 mg/L Phenanthrene, 112 mg/L Diclofop-methyl, 105 mg/L DDT
- Preparation: Solutions were prepared in methanol.

REPETITIONS
- Number of determinations: Injection was done in duplicate.

EVALUATION
- Calculation of capacity factor: k' = tr - t0 / t0; whereby tr: retention time (min), t0: dead time (min)
- Determination of the log Koc value: logKoc = logK' - A / B; whereby Koc: adsorption coefficient, k': capacity factor, A: intercept of the calibration curve, B: slope of the calibration curve

Batch equilibrium or other method

Analytical monitoring:

yes

Details on sampling:

Not applicable.

Details on matrix:

Not applicable.

Details on test conditions:

Not applicable.

Computational methods:

Not applicable.

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

log Koc

Value:

> 5.63

Temp.:

30 °C

Adsorption coefficient 2

Type:

Koc

Value:

> 427 000

Temp.:

30 °C

Results: HPLC method

Details on results (HPLC method):

The test substance does not contain any test relevant dissociation constants; thus, the experiment was carried out at approximately neutral pH in a non-ionized form. A good first order correlation was observed in the calibration curve for the reference standards and the retention times between duplicate injections for each solution was consistent. Therefore, the HPLC method was considered valid for the determination of adsorption coefficient. Based on the chromatographic data, the test substance is considered as stable during the test procedure.

Results: Batch equilibrium or other method

Adsorption and desorption constants:

Not applicable.

Recovery of test material:

Not applicable.

Concentration of test substance at end of adsorption equilibration period:

Not applicable.

Concentration of test substance at end of desorption equilibration period:

Not applicable.

Transformation products:

not measured

Details on results (Batch equilibrium method):

Not applicable.

Statistics:

None reported.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

Validity criteria of the applied guideline were fulfilled.

Conclusions:

The study report describes a valid guideline study conducted under certificated GLP compliance. The adsorption coefficient Koc > 427000 (that should be also applicable for the structurally similar long-chain homologue ‘1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-dodecanethiol') indicatese, that the test substance can be considered as environmentally immobile.

Executive summary:

The adsorption coefficient (Koc) of the closely related UVCB substance '1,3,4-Thiadiazolidine-2,5-dithione, reaction product with hydrogen peroxide and tert-nonanethiol' was determined using the High Performance Liquid Chromatography (HPLC) method according to OECD Guideline 121 / EU Method C.19. The test substance interacts with the stationary phase of the cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties. The dual composition of the stationary phase, having polar and non-polar sites allows for interaction of polar and non-polar groups of the test substance in a similar way as it is the case for organic matter in soil or sewage sludge matrices. In particular for polar substances, the pH has a significant influence on sorption behaviour. The test substance, however, does not contain any relevant dissociation constants, thus the experiment was carried out at approx. neutral pH in a non-ionized form of the test substance. 12 reference standard solutions, each prepared in methanol, where used (i.e. Acetanilide, Phenol, Atrazine, Isoproturon, Triadimenol, Linuron, Naphthalene, Endosulfan-diol, Fenthion, Phenanthrene, Diclofop-methyl, DDT). Also the test substance was diluted to 100 mL with methanol before analysis. The adsorption coefficient Koc (that should be also applicable for the structurally similar long-chain homologue ‘1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-dodecanethiol') was determined to be > 4.27 x 10e5 with a corresponding logKoc of > 5.63.

In accordance to the classification scheme of McCall et al. (1981), the test substance and also the closely related substance ‘1,3,4-Thiadiazolidine-2,5-dithione, reaction products with hydrogen peroxide and tert-dodecanethiol’ are therefore considered to be environmentally immobile.