Alcohols, C12-13, branched and linear, ethoxylated, sulfates, sodium salts

Additional physico-chemical information

Administrative data

Endpoint:

other: Membrane-water partition co-efficient

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

06 Feb 2023

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Cross-reference

Reason / purpose for cross-reference:

other: Specific composition tested

Reference

Type of composition:

legal entity composition of the substance

State / form:

liquid

Related composition:

Alcohols C12-13, branched and linear, ethoxylated (1-2,5 EO) sulphated, sodium salts - Consortium boundary

Alcohols C12-13, branched and linear, ethoxylated (1-2,5 EO) sulphated, sodium salts - Unilever

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Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2023

Report date:

2023

Materials and methods

Principles of method if other than guideline:

Stock solutions (~1 mM) of Alcohols C12-13, branched and linear, ethoxylated (1-2,5 EO) sulphated, sodium salts (hereafter referred to as SPES) were prepared in deionised water, and then further diluted in 2-oleoyl-1-palmitoyl-sn-glycero-3-phosphocholine (POPC) medium for donor tissue samples or phosphate-buffered saline (PBS) for reference controls.

Prepared donor, controls and PBS blank solutions (400µL) were added to the red well of the rapid equilibrium dialysis (RED) plate, with PBS buffer (600µL) added to the white well. The plate was sealed and incubated at 37ºC. on an orbital shaker at ~80 rpm to allow equilibration through the membrane between the two wells. After removal from the incubator, and equilibration to room temperature, aliquots were taken to an autosampler vial. Acetonitrile was added, before a brief vortex prior to analysis.

Analysis was conducted on both red and white wells for control samples and blanks prepared in PBS and only the white wells for donor samples. Various concentrations of donor dose concentrations and incubation times have been used.

Analysis was carried out by Liquid Chromatography with Electrospray triple quadrupole detection. Identification was by using Multiple reaction monitoring (MRM), a highly sensitive method of targeted mass spectrometry (MS). Quantitation is carried out by mixed analyte external calibration curve. Data reported is of multiple analyses.

GLP compliance:

no

Remarks:

Study does not make any claim of GLP compliance however it was conducted according to the principles of GLP within a GLP accredited laboratory.

Test material

Test material information

Constituent 1

Reference substance name:

Alcohols, C12-13, branched and linear, ethoxylated, sulfates, sodium salts

EC Number:

500-513-4

EC Name:

Alcohols, C12-13, branched and linear, ethoxylated, sulfates, sodium salts

Cas Number:

161074-79-9

Molecular formula:

not applicable; UVCB

IUPAC Name:

Alcohols, C12-13, branched and linear, ethoxylated, sulfates, sodium salts

Test material form:

liquid: viscous

Remarks:

Very viscous liquid

Details on test material:

Molecular weight: 316 g/mol
Expiry Date: 01/10/2023

Results and discussion

Results:

Analysis is carried out on both blanks, controls and donor samples, where blanks have no test material, controls have no liposome, and donor samples contain both. The Limit of quantitation (LOQ) is determined from the blank sample and defined as the concentration of the calibration standard that has an area 3 x carryover/blank level.

The data reported is where the incubation time has demonstrated equilibrium of concentration by analysis of red and white well data for the control samples. The control white well is considered the nominal concentration for the calculation. This assumes any losses due to non-liposome effects, i.e. plastic binding are equivalent to those seen in the donor samples.

All valid data are included below, demonstrating the need to ensure both equilibrium between the red and white portion of the control cells and also understand the background levels of each individual component. Different incubation times and concentrations of dose appear to impact the calculated LogKmw. It is not clear if this is an actual effect or method variability.

The branched SPES material calculated as part of the same analysis as the linear and branched for SPES shows a clear lowering of calculated LogKmw. This is likely the cause of the shift in calculated SLES and SPES values for C12 components.

Any other information on results incl. tables

Calculated LogKmw

	SPES^#@200		SPES^#@400
	Linear (incl some branched)	Branched	Linear (incl some branched)	Branched
C11AS	4.15		3.55
C12 AS	4.57	3.70	4.08	3.45
C13AS	5.10	4.34	4.65	4.14
C14 AS	<LOQ		<LOQ
C12EO1	<LOQ		4.32
C12EO2	4.51		4.11
C12EO3	4.48		4.06
C12EO4	<LOQ		3.91
C13EO1	5.14		4.77
C13EO2	4.98		4.64
C13EO3	4.83		4.49
C13EO4	4.66		4.39
C13EO5	4.63		4.27

 

^# SPES analysis also contain some branched material, this branching is known to lower the reported value. C12AS, C13AS n=2 for linear analysis.

 

Calculations

LogKmw = log10 {c_membrane / (n_water x dilution from well x 0.000000001)}

c_membrane = {n_membrane / (Conc Liposome mM) x (vol Liposome mL) x (mwt Liposome) x 0.0000001}

n_membrane = n_dose - n_water

n_dose = measured data from white control well x dilution from well

n_water = measured data from white donor well x dilution from well

Applicant's summary and conclusion

Conclusions:

To support (Q)SAR predictions for aquatic toxicity, membrane-water partition co-efficients ranging from 3.45 to 5.14 were determined for the components of a representative specification of SPES.

Executive summary:

An analytical study was conducted to generate membrane-water partition co-efficient values for the components of a representative specification of SPES. The resulting values, ranging from 3.45 to 5.14, were taken forward as part of (Q)SAR predictions for the aquatic toxicity of this substance.