Propionaldehyde, reaction product with formaldehyde

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:

from 2009-11-16 to 2010-03-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other 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:

other: HPLC column

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material:

PHYSICO-CHEMICAL PROPERTIES
- Water solubility: > 100 g/L
- pKa (calculated by the software PALLAS pKa Prediction Module 5.1, version 3.7.1.1): The calculated pKa's of the test substance are
13.1 and 14.0 (acidic groups)
- log Pow*: 1.67

Radiolabelling:

no

Test temperature:

35 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Finnigan Surveyor
- Type: HPLC
- analytical column: LiChrospher 100 CN 5 µm 150*3 mm; Col. No. Q31021; ARC Seibersdorf
- Detection system: DAD (UV 210 nm)

MOBILE PHASES
- Type: 35 % methanol (Chromasolv, Sigma-Aldrich, Lot. No. 9001S); 65 % buffer pH 6.5 in water(10 mMol/L potassiumdihydrogencitrate)
- Experiments with additives carried out on separate columns: no
- pH: 6.5
- Solutes for dissolving test and reference substances: Methanol and mobile phase

DETERMINATION OF DEAD TIME
The dead time t0 was determined by an unretained compound (sodium nitrate; assay 99.6 %; Lot 50330; Riedel de Haen).

REFERENCE SUBSTANCES
see results

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: see results
- Quantity of reference substances: see results
- Intervals of calibration: on day of analysis

REPETITIONS
- Number of determinations: 2

EVALUATION
According to the guidelines a minimum of six reference points, if possible at least one above and one below the expected value of the test substance should be used.
Freshly prepared solutions of six reference compounds in the mobile phase were injected individually to identify their peak in this HPLC-system. Then they were injected simultaneously (before and after the test substance) and the exact retention times were determined in duplicate. The corresponding capacity factors and logarithms of the capacity factors were calculated and plotted as a function of the log KOC.
A linear regression line was calculated from the data of this graph.
The log KOC values of the reference compounds are described in the guidelines.

SELECTION of pH
According to the guideline two tests should be performed, for ionisable substances with both ionised and non-ionised forms but only in cases where at least 10 % of the test compound will be dissociated within pH 5.5 to 7.5.
The pKa of the test substance was estimated using an atom/fragment contribution method (Software Pallas 3.7.1.1 pKa prediction module pKalc 5.1). The calculated pKa's of the test substance are 13.1 and 14.0 (acidic groups).
The undissociated test substance can be obtained by adjusting the pH to at least one pH-unit below the pKa of the acidic group and at least one pH-unit above the pka of the basic group.
The test substance will exist in the undissociated form between pH 5.5 to 7.5 and therefore only a main tests at pH 6.5 was performed.

Key result

Type:

log Koc

Value:

1.16 dimensionless

Details on results (HPLC method):

The actual pH value of the mobile phase during the test was 6.5.
The temperature during the test was 35 °C.
The calibration curve of the reference substances was: log k' = 0.4092 x log KOC – 0.491.
The results of the individual determinations of the decadic logarithm of the adsorption coefficient log Koc of the test substance were 1.16 and 1.16. The mean adsorption coefficient log KOC of the test substance is 1.16* at pH 6.5.
The values of log Koc derived from two measurements were within a range of 0.25 log unit.
*The experimentally determined log Koc is outside the range (1.5 to 5.0) for which the method is published in the guideline.
Results for reference and test substances see attachment

Validity criteria fulfilled:

yes

Conclusions:

An adsorption/desorption test was performed according to OECD 121. The mean adsorption coefficient log Koc of the test substance was determined to be 1.16 at pH 6.5.

Executive summary:

The adsorption coefficient (log Koc) was determined using HPLC.

The actual pH value of the mobile phase during the test was 6.5.

The temperature during the test was 35 °C.

The calibration curve of the reference substances was: log k' = 0.4092 x log Koc – 0.491.

The results of the individual determinations of the decadic logarithm of the adsorption coefficient log Koc of the test substance were 1.16 and 1.16. The mean adsorption coefficient log Koc of the test substance is 1.16* at pH 6.5. The values of log Koc derived from two measurements were within a range of 0.25 log unit.

*The experimentally determined log Koc is outside the range (1.5 to 5.0) for which the method is published in the guideline.

Description of key information

 An adsorption/desorption Test was performed according to OECD 121 (2001). The mean adsorption coefficient log Koc of the test substance was determined to be 1.16 at pH 6.5.

Key value for chemical safety assessment

Koc at 20 °C:

15

Additional information

An adsorption/desorption Test was performed according to OECD 121. The log Koc was estimated using an atom/fragment contribution method (Software KOCWIN® v 2.00).

The adsorption coefficient (log Koc) was determined using HPLC. The adsorption coefficient was estimated at pH 6.5 using the retention times of the test substance and of six reference substances. The dead time was determined using sodium nitrate. The dissotiation constant pKa of the test substance was calculated by the software PALLAS® pKa Prediction substance Module 5.1, version 3.7.1.1. The actual pH value of the mobile phase during the test was 6.5.

According to the guideline, two tests should be performed for ionisable substances with both ionised and non-ionised forms but only in cases whereat least 10 % of the test compoundwill be dissociated within pH 5.5 to 7.5.

The calculated pKa's of the test substance are 13.1 and 14.0 (acidic groups). Between pH 5.5 and 7.5 the test substanceis in the non ionised form. Therefore only one experimental test at pH 6.5 was performed.

The adsorption log Koc was determined to be-1.7 (MCI) and the coefficient log Koc for comparison was detemined to be -0.9 (log Kow). The experimental test at pH 6.5 was determined to be log KOC=1.2* at 35°C *The experimentally determined log Koc is outside the range (1.5 to 5.0) for which the method is published in the guideline.

The calibration curve of the reference substances was: log k' = 0.4092 x log KOC – 0.491.

The results of the individual determinations of the decadic logarithm of the adsorption coefficient log Koc of the test substance were 1.16 and 1.16. Therefore. the mean adsorption coefficient log Koc of the test substance is determined to be 1.16* at pH 6.5.