5,5-dimethylhydantoin

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Testing was conducted between 26 October 2009 and 19 November 2009.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 19-08-2008 Date of Signature: 04-09-2009

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

DMH

IUPAC Name:

DMH

Details on test material:

Sponsor's identification: DMH
Description: white crystalline solid
Batch number: N5439431
Date received: 24 February 2006
Storage conditions: room temperature in the dark

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Type:

log Pow

Partition coefficient:

-0.475

Temp.:

22.4 °C

pH:

6.6

Details on results:

The partition coefficient of the test material has been determined to be 0.335, log10 Pow, -0.475.

Any other information on results incl. tables

Results

 Preliminary estimate

Approximate solubility in n-octanol:         3.72 x 10^-2 g/l
Approximate solubility in water:               50.4 g/l
Approximate P_ow:                                        7.39 x 10^-4
Log₁₀P_ow:                                                      -3.13

Definitive test

The mean peak areas obtained for the standard, stock and sample solutions are shown in the following two tables:

Table 9.2– Organic Phase

Solution	MeanArea
Standard 10.1 mg/l	111.557
Standard 10.1 mg/l	114.344
Organic phase matrix blank	0.000
Sample 1	103.164
Sample 2	104.573
Sample 3	166.499
Sample 4	180.580
Sample 5	148.527
Sample 6	145.558

Table 9.3– Aqueous Phase

Solution	MeanArea
Standard 100 mg/l	1.062 x 10^3
Standard 101 mg/l	1.059 x 10^3
Aqueous phase matrix blank	0.000
Sample 1	658.866
Sample 2	667.413
Sample 3	908.860
Sample 4	931.595
Sample 5	779.151
Sample 6	790.433
Stock solution A	1.069 x 10^3
Stock solution B	1.070 x 10^3

The total weights (mg) and analysed concentration (mg/l) of the respective phases are shown in the following table:

Table 9.4

Sample Number	Total Weight (mg)*	Organic Phase		Aqueous Phase
		Analysed Concentration (mg/l)	Weight (mg)†	Analysed Concentration (mg/l)	Weight (mg)†	pH
1	45.6	184	16.6	625	28.1	7.0
2	45.6	187	16.8	633	28.5	6.8
3	93.3	297	13.7	861	79.3	7.0
4	93.3	323	14.8	883	81.2	6.8
5	65.9	265	17.2	739	48.0	6.9
6	65.9	260	16.9	749	48.7	6.8

pH of n-octanol saturated water:   6.7
pH of stock solution:                        6.6
Temperature:                                   22.4 ± 0.5°C

The partition coefficient determined for each sample is shown in the following table:

Table 9.5

Sample Number	Organic/Aqueous Volume Ratio	Partition Coefficient	Log10Pow	Mean Partition Coefficient
1	2:1	0.295	-0.530	0.295
2		0.295	-0.530
3	1:2	0.345	-0.462	0.355
4		0.365	-0.437
5	1:1	0.359	-0.445	0.353
6		0.347	-0.460

Mean P_ow : 0.335    log₁₀P_ow: -0.475     P_owstandard deviation : 3.14 x 10^-2

Validation

Linearities of the detector response with respect to concentration were assessed over the nominal concentration range of 0 to 200 mg/l for the aqueous and organic phases. These were satisfactory with correlation coefficients of 1.000 being obtained.

*From analysis of the stock solution

†From analysis of the respective phase

Applicant's summary and conclusion

Conclusions:

Conclusion
The partition coefficient of the test material has been determined to be 0.335, log10 Pow, -0.475.

Executive summary:

Method

The determination was carried out using the shake-flaskthod, Method A8 Partition Coefficient ofCommissionRegulation (EC) No 440/2008 of 30 May 2008.

Conclusion

The partition coefficient of the test material has been determined to be 0.335, log₁₀P_ow, -0.475.