2,3-dihydroxypropyl methacrylate

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:

Experimental starting date: 24 July 2017. Experimental completion date: 01 August 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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))

Deviations:

no

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Test temperature:

40 ºC

Details on study design: HPLC method:

The sample, dead time and reference standard solutions were injected in duplicate using the
following HPLC parameters:
HPLC System : Agilent Technologies 1200 series,
incorporating autosampler and workstation
Column : Phenomenex Luna CN, 5 μm, 100 Å
(150 x 4.6 mm)
Column temperature : 40 ºC
Mobile phase : 55:45 (v/v) methanol:purified water
pH of mobile phase : 6.34
Flow rate : 1.0 mL/min
Injection volume : 10 μL
UV detector wavelength : 210 nm

Sample No.:

#1

Type:

log Koc

Value:

< 1.25 dimensionless

pH:

6.34

Temp.:

40 °C

Sample No.:

#2

Type:

log Koc

Value:

< 1.25 dimensionless

pH:

6.34

Temp.:

40 °C

Details on results (HPLC method):

The calibration curve for the reference items showed good first order correlation (R = 0.9906) and the retention times between duplicate injections for each solution were consistent, indicating that the HPLC method was valid for the estimation of the adsorption coefficient of the test item.
pH may have a significant influence on sorption behavior, in particular for ionizable substances. However, since the test item does not present any dissociating functional groups within the environmentally relevant pH range of 5.5 to 7.5, no manipulation of the mobile phase pH was necessary to ensure testing of the test item in its unionized form. Therefore, only a single evaluation with the mobile phase at approximately neutral pH was performed.

Preliminary Estimation

The estimated adsorption coefficient values (log10 Koc) for the test item are summarized in the following table. Two separate estimation methodologies were employed: the first uses first order molecular connectivity index (MCI) and the second method replaces the MCI descriptor with the octanol-water partition coefficient (log10 Kow).

Test Item	Estimated Log10 Koc
	MCI Method	Log10 Kow Method
2,3-dihydroxypropyl methacrylate	1	-0.151

Calibration Curve

The retention times of the dead time and the retention times, capacity factors (k') and log10 Koc values for the reference items are shown in the two following tables.

Dead Time	Retention Time (min)		Mean Retention Time (min)
	Injection 1	Injection 2
Formamide	2.009	2.104	2.102

Reference Item	Retention Time (min)		Mean Retention Time (min)	Capacity Factor (k')	Log10 k'	Log10 Koc
	Injection 1	Injection 2
Acetanilide	2.357	2.357	2.357	0.121	-0.916	1.25
Phenol	2.308	2.308	2.308	9.80 x 10^-2	-1.01	1.32
Atrazine	2.6	2.6	2.6	0.237	-0.625	1.81
Triadimenol	2.945	2.945	2.945	0.401	-0.397	2.4
Linuron	3.032	3.027	3.03	0.442	-0.355	2.59
Naphthalene	3.435	3.435	3.435	635	-0.197	2.75
Endosulfan-diol	3.226	3.226	3.226	0.535	-0.271	3.02
Fenthion	3.926	3.931	3.929	0.869	-6.08 x 10^-2	3.31
Phenanthrene	5.053	5.058	5.056	1.41	0.148	4.09
α-Endosulfan	5.661	5.671	5.666	1.7	0.229	4.09
Diclofop-methyl	5.471	5.481	5.476	1.61	0.206	4.2
DDT	13.931	13.902	13.916	5.62	0.75	5.63

Test Item Adsorption Coefficient

The retention times, capacity factors and log10 Koc values determined for the sample are shown in the following table.

Injection	Retention time (min)	Capacity Factor (k')	Log10 k'	Log10 Koc	Mean Log10 Koc	Adsorption Coefficient (Koc)
1	2.138	1.73 x 10^-2	-1.76	<1.25	<1.25	<17.8
2	2.143	1.97 x 10^-2	-1.71	<1.25

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient (Koc) of the test item has been determined to be less than 17.8, log10 Koc less than 1.25. The mobility of the test item can therefore be classified as very high.

Executive summary:

The adsorption coefficient (Koc) of 2,3-dihydroxypropyl methacrylate has been determined to be less than 17.8, log10 Koc less than 1.25, using the HPLC screening method. The procedure was designed to be compatible with Method C.19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001. The mobility of the test item can therefore be classified as very high.

Description of key information

The adsorption coefficient (Koc) of the test item has been determined to be less than 17.8,

log10 Koc less than 1.25. The mobility of the test item can therefore be classified as very high.

Key value for chemical safety assessment

Koc at 20 °C:

17.8