Reaction mass of 1-(3,3-dimethylcyclohex-1-en-1-yl)pent-4-en-1-one and 1-(5,5-dimethylcyclohex-1-en-1-yl)pent-4-en-1-one

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 July 2015-16 September 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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))

Version / remarks:

(2008)

Deviations:

no

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))

Version / remarks:

(2001)

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Radiolabelling:

no

Details on study design: HPLC method:

PKA CALCULATION
- Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International San Francisco, USA)
- Calculated pKa values in the logarithm range of 1-14:
pKa acidic groups: none
pKa basic groups: none

Based on the calculated pKa values, the mobile phase was not buffered.

HPLC CONDITIONS
- Instrument: Acquity UPLC system (Waters, USA)
- Detector: Acquity UPLC TUV (Waters)
- Column: Acquity UPLC HSS Cyano, 100 mm x 2.1 mm i.d., dp = 1.8 µm (Waters)
- Column temperature: 35°C ± 1°C
- Mobile phase: 55/45 (v/v) methanol/water
- Flow: 0.4 mL/min
- Injection volume: 5 µL
- UV detection: 210 nm

UNRETAINED SUBSTANCE
- Formamide; dissolved in 55/45 (v/v) methanol/water

REFERENCE SUBSTANCES
- 8 Reference substances in the log Koc range of 1.26 - 5.63: see the table in the result section.
- 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.

TEST SUBSTANCE
- A 2000 mg/L stock solution of the test substance was prepared in methanol. The stock solution was diluted to obtain an end solution of 55/45 (v/v) methanol/water. The final concentration of the test substance solution was 20.0 mg/L.

PERFORMANCE OF THE TEST
- Solutions of the unretained substance, the reference substances and the test substance were injected in duplicate.
- Blank solution (55/45 (v/v) methanol/water) was analysed by single injection.

DATA HANDLING
- Dead time (t0) was calculated as the mean retention time of the unretained substance.
- Two capacity factors (k') were calculated for each reference substance: k'= (tr-t0)/t0 where tr = single retention time and t0=dead time
- Log k’ values of the references substances were plotted against the log Koc values (see table below).
- Linear regression analysis (least squares method) was used to calculate the regression line.
- Regression line: log k’ = 0.316 x log Koc– 0.859 (r=0.98, n=16)
- Capacity factor (k') of the test substance was calculated from its mean retention time (tr) and the dead time (t0): k'= (tr-t0)/t0
- Log Koc of the test substance was calculated by substituting the log k’ in the regression line
- The values of log Koc calculated from the individual test substance retention times were within a range of ± 0.25 log unit.

Key result

Type:

log Koc

Value:

3.44 dimensionless

Temp.:

20 °C

Remarks on result:

other: Koc= 2.8E03 L/kg

Details on results (HPLC method):

In the HPLC chromatogram of the test substance solution, one test substance peak was observed.

Table: Results HPLC method for adsorption coefficient 

Substance	tr,1 [min]	tr,2 [min]	mean tr (n=2)	log Koc (1)	Koc	Area %
Formamide (t0)	0.664	0.665	0.665
Acetanilide	0.861	0.860		1.26
Monuron	1.043	1.041		1.99
2,5-Dichloroaniline	1.180	1.177		2.55
Naphthalene	1.361	1.356		2.75
Benzoic acid phenylester	1.579	1.572		2.87
Fenthion	2.063	2.048		3.31
Phenanthrene	2.294	2.280		4.09
4,4’-DDT	5.564	5.499		5.63
Galbascone	1.784	1.783	1.784	3.44	2.8E03	100

 

(1) Log Koc values of the reference substances according to OECD 121 are based on soil adsorption data.

Conclusions:

Using HPLC method and soil-adsorption-reference data, the log Koc for the substance was estimated to be 3.44.

Executive summary:

The HPLC estimation method was applied for the determination of the adsorption coefficient (Koc) of the substance. The study was performed according to EC C.19 and OECD 121. The mobile phase was 55/45 (v/v) methanol/water. The column temperature was 35°C. In the HPLC chromatogram of the test substance solution, one test substance peak was observed. Using soil-adsorption-reference data, the log Koc value for the substance was estimated to be 3.44 (Koc= 2.8E03).

Description of key information

The Koc of the substance was determined to be 2.8E03 L/kg; the log Koc 3.44.

Key value for chemical safety assessment

Koc at 20 °C:

2 800

Additional information

The HPLC estimation method was applied for the determination of the adsorption coefficient (Koc) of the substance. The study was performed according to EC C.19 and OECD 121. The mobile phase was 55/45 (v/v) methanol/water. The column temperature was 35°C. In the HPLC chromatogram of the test substance solution, one test substance peak was observed. Using soil-adsorption-reference data, the log Koc value for the substance was estimated to be 3.44 (Koc= 2.8E03 L/kg).

[LogKoc: 3.44]