4,4'-Isopropylidenediphenol, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with 3-aminomethyl-3,5,5-trimethylcyclohexylamine

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

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

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Details on study design: HPLC method:

A standard solution for calibration was prepared which contained the reference compounds. The calibration standard was analyzed in duplicate, followed by duplicate analyses of the test material. Finally, the calibration standard was again analyzed in duplicate. Retention times (tR) for each of the reference compounds were determined based on detection of chromatographic peaks in the refractive index detector (RID). Assignments of chromatographic peaks to the reference compounds were confirmed by analysis of single component standards and detection of chromatographic peaks in the RID. The dead time (to) for the HPLC assay was determined from duplicate analyses of a solution containing urea, a substance recommended in the test guideline as one which is not retained on the HPLC column under the test conditions. Stock solutions of the test substance, BADGE, and IPD were prepared in methanol and diluted in methanol/water (55%/45%; v/v) for analysis, which was performed using duplicate samples. The concentrations of the test and reference compounds were minimized to avoid the potential for overloading the HPLC column, yet allowing adequate sensitivity
for detection in the HPLC assay. The concentration of BADGE-IPD (#33) in the test solution was 200 milligrams per liter (mg/L). Reference compound concentrations in the standard solution were 50 mg/L per compound. The concentrations of urea, BADGE, and IPD in the analyzed solutions were each 200 mg/L.To ensure the reproducibility of compound retention times in the HPLC assay, a constant temperature of 30°C was maintained by the HPLC column heater.

Computational methods:

The HPLC capacity factor (k’) for reference materials and the test materials in the HPLC assay was determined from the retention time for the compounds (tR) and the dead time (to) for the column using the following formula: k’ = (tR-to)/to (Note: tR and to are measured in minutes). The log k’ data for the reference materials was plotted against their log Koc values and a linear regression line determined. Estimated log Koc values for the test materials were determined from their measured capacity factor using the equation for the fitted regression line, and a weighted average was taken.

Type:

log Koc

Value:

> 5.6

Temp.:

30 °C

Details on results (HPLC method):

Under buffered mobile phase conditions, the component substance BADGE eluted as one major peak with an average retention time of 4.02 minutes. This retention time corresponds to an average estimated Koc value of 3.91, which is similar to that predicted for BADGE by KOCWIN (predicted log Koc of 3.81). Peaks with similar retention time characteristics to the major BADGE peak were not detected in BADGE-IPD, and residual unreacted BADGE is not expected to be present in the test substance (Harfmann, 2012). IPD was not detected under study conditions employing buffered mobile phase at the reference wavelength of 210 nm, and the chromatograms for IPD samples were similar to those obtained for blank samples (Figure 6). KOCWIN’s molecular connectivity index method predicts a log Koc value of 2.3 for the IPD component (USEPA, 2010). BADGE-IPD components representing products of the BADGE-IPD adduct were not detected in this study, and the chromatograms for BADGE-IPD samples were similar to those obtained for blank samples (Figure 6). BADGE-IPD adducts are expected to retain structural features of BADGE, and should be similarly detectable at the reference wavelength of 210 nm. Furthermore, chromatograms for BADGE-IPD do not indicate elution of the test substance in the void volume. These observations suggest that the retention time of adduct products present in BADGE-IPD was longer than could be observed under study conditions. Therefore, the BADGE-MXDA adducts are estimated to have a log Koc higher than 5.63 (the value attributed to DDT), and likely higher than 6.59 (the estimated log Koc value corresponding to the maximumelution time of the HPLC assay).

Validity criteria fulfilled:

yes

Conclusions:

BADGE-IPD is estimated to have a log Koc value > 5.63 (the log Koc value of DDT) and likely > 6.59 (the estimated log Koc value corresponding to the maximum elution time of the HPLC assay).

Executive summary:

The soil adsorption coefficient (Koc) for BADGE-IPD was estimated using Organisation for Economic Co-operation and Development (OECD) Guideline 121: “Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using

High Performance Liquid Chromatograpy (HPLC)”. This method compares the retention time of the test substance in a defined HPLC assay to the retention times of a series of reference substances with known Koc values. The reference substances utilized for this study included acetanilide, methyl benzoate, naphthalene, 1,2,3-trichlorobenzene, phenanthrene and DDT. For comparison purposes, the HPLC method was also used to estimate Koc values for unreacted BADGE and IPD. A linear regression line for reference substances was determined using the log k’ data plotted against the known log Koc values. The k’ value was the HPLC capacity factor derived from the retention time for the substance corrected for the dead volume in the HPLC column. The Koc of the test substance was then determined from its measured HPLC capacity factor using the equation for the fitted regression line. Under HPLC assay conditions, chromatographic peaks were not observed for BADGE-IPD at the reference wavelength of 210 nanometers (nm). Chromatographic peaks were detected for BADGE at this reference wavelength, which suggests that BADGE-IPD adduct compounds should be detectable at 210 nm. The lack of detectable peaks for BADGE-IPD therefore suggests that BADGE-IPD has a retention time longer than that of DDT under assay conditions. BADGE-IPD is therefore estimated to have a log Koc value > 5.63 (the log Koc value of DDT) and likely > 6.59 (the estimated log Koc value corresponding to the maximum elution time of the HPLC assay). This interpretation is supported by quantitative structural activity relationship (QSAR) analysis of BADGE-IPD, which predicts a log Koc ≥ 5.9 for BADGE-IPD adduct products.

Description of key information

The soil adsorption coefficient (Koc) for BADGE-IPD adduct was estimated using Organisation for Economic Co-operation and Development (OECD) Guideline 121:  “Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatograpy (HPLC).

Key value for chemical safety assessment

Koc at 20 °C:

3 890 000

Other adsorption coefficients

Type:

log Kp (solids-water in soil)

Value in L/kg:

4.89

at the temperature of:

20 °C

Other adsorption coefficients

Type:

log Kp (solids-water in sediment)

Value in L/kg:

5.29

at the temperature of:

20 °C

Other adsorption coefficients

Type:

log Kp (solids-water in suspended matter)

Value in L/kg:

5.59

at the temperature of:

20 °C

Other adsorption coefficients

Type:

log Kp (solids-water in raw sewage sludge)

Value in L/kg:

6.07

at the temperature of:

20 °C

Other adsorption coefficients

Type:

log Kp (solids-water in settled sewage sludge)

Value in L/kg:

6.07

at the temperature of:

20 °C

Other adsorption coefficients

Type:

log Kp (solids-water in activated sewage sludge)

Value in L/kg:

6.16

at the temperature of:

20 °C

Other adsorption coefficients

Type:

log Kp (solids-water in effluent sewage sludge)

Value in L/kg:

6.16

at the temperature of:

20 °C

Additional information

The soil adsorption coefficient (Koc) for BADGE-IPD was estimated using Organisation for Economic Co-operation and Development (OECD) Guideline 121: “Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using

High Performance Liquid Chromatograpy (HPLC)”. This method compares the retention time of the test substance in a defined HPLC assay to the retention times of a series of reference substances with known Koc values. The reference substances utilized for this study included acetanilide, methyl benzoate, naphthalene, 1,2,3-trichlorobenzene, phenanthrene and DDT. For comparison purposes, the HPLC method was also used to estimate Koc values for unreacted BADGE and IPD. A linear regression line for reference substances was determined using the log k’ data plotted against the known log Koc values. The k’ value was the HPLC capacity factor derived from the retention time for the substance corrected for the dead volume in the HPLC column. The Koc of the test substance was then determined from its measured HPLC capacity factor using the equation for the fitted regression line. Under HPLC assay conditions, chromatographic peaks were not observed for BADGE-IPD at the reference wavelength of 210 nanometers (nm). Chromatographic peaks were detected for BADGE at this reference wavelength, which suggests that BADGE-IPD adduct compounds should be detectable at 210 nm. The lack of detectable peaks for BADGE-IPD therefore suggests that BADGE-IPD has a retention time longer than that of DDT under assay conditions. BADGE-IPD is therefore estimated to have a log Koc value > 5.63 (the log Koc value of DDT) and likely > 6.59 (the estimated log Koc value corresponding to the maximum elution time of the HPLC assay). This interpretation is supported by quantitative structural activity relationship (QSAR) analysis of BADGE-IPD, which predicts a log Koc ≥ 5.9 for BADGE-IPD adduct products.

[LogKoc: 6.59]