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Reference
Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2010-08-24 to 2010-09-03
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP 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))
Deviations:
yes
Remarks:
A first first using UV detection as foreseen in the study plan gave too weak a signal. Therefore the test was repeated using RI detector. Only the results of the second test are reported.
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:
yes
Remarks:
as above
GLP compliance:
yes (incl. QA statement)
Type of method:
HPLC estimation method
Media:
soil/sewage sludge
Specific details on test material used for the study:
- Names of test material (as cited in study report): Aldehyde C10 decyclic food grade; decanal
- Substance type: Colourless liquid
- Physical state: Liquid
- Purity test date: No data
- Lot No: VE00097618
- Expiration date of the lot: 2011-06-01
- Stability under test conditions: No data
- Storage condition of test material: No data
Radiolabelling:
no
Test temperature:
35 °C
Details on study design: HPLC method:
EQUIPMENT
- Apparatus: HPLC equipment - a Perkin Elmer (series 200) HPLC system comprising (1) a high pressure pump, (2) an autosampler (3) a column compartment (4) a variable wavelength detector
- Analytical (guard) column: 150 mm height × 4.6 mm diameter Nucleodor 100-5 CN-RP (Macherey-Nagel), serial No. N8030929, batch No. 3034

DETERMINATION OF DEAD TIME
- Method: by inert substance (formamide) which is not retained by the column.

REFERENCE SUBSTANCES
- Formamide (CAS No. 75-12-7, logKoc="dead time", conc. = 4.0 g/L, 99.6 % pure)
- 2-Nitrobenzamide (CAS No. 610-15-1, logKoc = 1.45, conc. = 0.20 g/L, 98.7 % pure)
- Methyl benzoate (CAS No. 93-58-3), logKoc = 1.80, conc. = 0.20 g/L, 99.9 % pure)
- Naphthalene (CAS No. 91-20-3, logKoc =2.75, conc. = 0.05 g/L, 99.9 % pure)
- 1,2,3-Trichlorobenzene, (CAS No. 87-61-6, logKoc =3.16, conc. = 0.20 g/L, 99.9 % pure)
- Phenanthrene (CAS No. 85-01-8, logKoc =4.09, conc. = 0.10 g/L, 99.2 % pure)
- 4,4'-DDT (CAS No. 50-29-3, logKoc =5.63, conc. = 0.20 g/L, 96.0 % pure)

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 12.5 mg in 50 µL methanol/water 55/45 % v/v mixture
- Calibration mix a: 2 mL each of stock solutions of formamide, methyl benzoate, naphthalene and phenantrene, enough ultrapure water to obtain a solvent composition similar to the mobile phase (6.55 mL).
- Calibration mix b: 2 mL each of stock solutions of 2-nitrobenzamide, 1,2,3-trichlorobenzene, and 4,4'-DDT, enough ultrapure water to obtain a solvent composition similar to the mobile phase (4.91 mL).
- Injection sequence of solutions: calibration a, calibration b, test, test, calibration a, calibration b.

REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k': Calculated using the equation k = tR/t0 - 1,
-- where tR = retention time and t0 = "dead time", i.e. retention time of formamide
- Retention times were measured.
- Determination of the log Koc value: Linear regression parameters of the relationship log Koc = f(log k) was calculated from the data obtained from the calibration mixture.
-- From this, the log Koc of the test substance was determined from its measured capacity factor.
Analytical monitoring:
not specified
Type:
log Koc
Value:
2.9
Temp.:
35 °C
Details on results (HPLC method):
- For details of results and calculations please see Appendix 1 (attached).
- The results are graphed in Appendix 2 (attached).
- Chromatogram of the reference substances is attached (Appendix 3)
- Chromatogram of the test substance is attached (Appendix 4)

The determination was performed at 35 °C (temperature of the column) but the value obtained can be considered to represent the value at an unspecified, probably ambient temperature since no mention is made in the guidelines of the temperature at which the tabulated reference substances log Koc values were determined. Adsorption coefficients of the test and reference substances are assumed to vary with temperature in the same way.

Validity criteria fulfilled:
yes
Conclusions:
The adsorption coefficient of the test substance was assessed according to OECD guideline 121. The chromatograms of the test substance show one peak at an average retention time of 4.03 minutes, corresponding to an adsorption coefficient (log value) of 2.9. Therefore the adsorption coefficient (Koc) of decanal is log Koc 2.9.

Description of key information

Log Koc 2.9 (OECD 121)

Key value for chemical safety assessment

Koc at 20 °C:
794

Additional information

The adsorption coefficient of the test substance was assessed according to OECD guideline 121. The chromatograms of the test substance show one peak at an average retention time of 4.03 minutes, corresponding to an adsorption coefficient (log value) of 2.9. Therefore the adsorption coefficient (Koc) of decanal is log Koc 2.9, equivalent to a Koc of 794.