Bis[bis(3,5,5-trimethylhexyl)dithiocarbamate-S,S']zinc

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

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))

GLP compliance:

yes

Type of method:

HPLC estimation method

Test material

Test material information

Constituent 1

Reference substance name:

Bis[bis(3,5,5-trimethylhexyl)dithiocarbamate-S,S']zinc

EC Number:

283-381-8

EC Name:

Bis[bis(3,5,5-trimethylhexyl)dithiocarbamate-S,S']zinc

Cas Number:

84604-96-6

Molecular formula:

C38H76N2S4Zn

IUPAC Name:

bis({[bis(3,5,5-trimethylhexyl)carbamothioyl]sulfanyl})zinc

Test material form:

solid: particulate/powder

Study design

HPLC method

Details on study design: HPLC method:

Instrument Acquity UPLC system
(Waters, Milford, MA, USA)
Detector Acquity UPLC TUV detector (Waters) or
Acquity UPLC PDA detector (Waters)
Column Acquity UPLC HSS Cyano,
100 mm  2.1 mm i.d., dp = 1.8 µm (Waters)
Column temperature 35°C  1°C
Injection volume 5 µL
Mobile phase
Solvent A methanol
Solvent B water
Gradient
Time
[minutes] Solvent A
[%] Solvent B
[%]
0 55 45
12 55 45
13 100 0
17.5 100 0
18 55 45
20 55 45
Flow 0.4 mL/min
UV detection 210 nm (unretained compound, reference substance and test solution)
285 nm (test solution)

Batch equilibrium or other method

Details on sampling:

Preparation of Solutions
Solution of the Unretained Compound
A 5 g/L stock solution of formamide (99.2%, [75-12-7], Alfa Aesar, Karlsruhe, Germany) in methanol was used. The stock solution was diluted to obtain an end solution of 55/45 (v/v) methanol/water.
The formamide blank solution was 55/45 (v/v) methanol/water.
Reference Substance Solution
Stock solutions of the reference substances at concentrations of approximately 1 g/L in methanol were used. The stock solutions were diluted to obtain an end solution of 55/45 (v/v) methanol/water.
The blank solution for the mixture of reference substances was 55/45 (v/v) methanol/water.
Text Table 3
Reference Substances
Reference substance Purity CAS number Supplier log Koc 1
Acetanilide 99.8% 103-84-4 Sigma-Aldrich 1.26
Monuron 99.9% 150-68-5 Sigma-Aldrich 1.99
2,5-Dichloroaniline 99.9% 95-82-9 Merck 2.55
Naphthalene 99.5% 91-20-3 Acros Organics 2.75
Benzoic acid phenylester 99.9% 93-99-2 Sigma-Aldrich 2.87
Fenthion 97.5% 55-38-9 Sigma-Aldrich 3.31
Phenanthrene 98.1% 85-01-8 Acros Organics 4.09
4,4’-DDT 98.7% 50-29-3 Sigma-Aldrich 5.63
1 values according to the OECD 121 guideline based on soil adsorption data
Acros Organics, Geel, Belgium
Merck, Darmstadt, Germany
Sigma-Aldrich, Steinheim, Germany

Test Solution
A 1000 mg/L stock solution of the test item was prepared in acetonitrile. The solution was ultrasonicated for 5 or 30 minutes. The stock solution was 2 fold diluted with acetonitrile. The final concentration of the test item solution was 500 mg/L.
The test item blank solution was acetonitrile.
Sample Injections
Reference substance and test item solutions were injected in duplicate. Blank solutions were analyzed by single injection.

Results and discussion

Adsorption coefficient

Key result

Sample No.:

#1

Type:

log Koc

Value:

> 5.6

pH:

7

Results: HPLC method

Details on results (HPLC method):

Koc HPLC Method
UPLC-UV chromatograms of the test item solution and the corresponding blank are shown in Figure 1 and Figure 2, respectively. In the chromatogram of the test item solution, peaks with a retention time of about 15 minutes were observed. Under the same analytical conditions, the retention time of 4,4’-DDT (log Koc = 5.6) was 5.8 minutes.
Since there was a difference in responses between the duplicate injection of the test item solution extra tests were performed. The tests showed that the test item most probably precipitates on top of the column when using an aqueous mobile phase. The test item only elutes in 100% organic mobile phase.
From the tests performed, it was concluded that the log Koc of test item was > 5.6
(Koc > 4.3 x 10E5).

Results: Batch equilibrium or other method

Transformation products:

not measured

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of Zinc diisononyl dithiocarbamate.
The log Koc value of the test item at neutral pH was >5.6.