Formaldehyde, oligomeric reaction products with acetone and diphenylamine

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:

11 July 2016 to 9 December 2016

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

Media:

soil

Radiolabelling:

no

Test temperature:

Column temperature: 40 degrees C

Details on study design: HPLC method:

EQUIPMENT
Instrument: Acquity UPLC system (Waters, Milford, MA, USA)
Detector: Xevo TQ-S mass spectrometer (Waters)
Column: Acquity UPLC BEH C18, 50 mm x 2.1 mm i.d., dp = 1.7 µm (Waters)
Column temperature: 40°C +/- 1°C
Injection volume: 50 µL
Flow: 0.5 mL/min
MS detection
Ionisation source: ESI+
Cone voltage : 25 V
Collision energy: 22 eV, 24 eV and 25 eV
Acquisition: m/z 170 to m/z 93, m/z 391.2 to m/z 182
m/z 212.1 to m/z 120, m/z 351 to m/z 182,
Quantitation: m/z 170 to m/z 93, m/z 391.2 to m/z 182

MOBILE PHASES
Mobile phase : A – 0.1% formic acid in acetonitrile, B – 0.1% formic acid in water
Gradient:
Time
[minutes] %A %B

0 50 50
1.5 50 50
4 98 2
6 98 2
6.1 50 50
8 50 50

DETERMINATION OF DEAD TIME
- Method: by means of homologous series

REFERENCE SUBSTANCES
Stock solutions of the reference substances at concentrations of approximately 1 g/L in methanol were used. The stock solutions were diluted to obtain an end solution of 55/45 (v/v) methanol/water.
The blank solution for the mixture of reference substances was 55/45 (v/v) methanol/water.


Reference substance Purity CAS number Supplier log Koc#

Acetanilide 99.8% 103-84-4 Sigma-Aldrich 1.26
Monuron 99.9% 150-68-5 Sigma-Aldrich 1.99
2,5-Dichloroaniline 99.9% 95-82-9 Merck 2.55
Naphthalene 99.5% 91-20-3 Acros Organics 2.75
Benzoic acid phenylester 99.9% 93-99-2 Sigma-Aldrich 2.87
Fenthion 97.5% 55-38-9 Sigma-Aldrich 3.31
Phenanthrene 98.1% 85-01-8 Acros Organics 4.09
4,4’-DDT 98.7% 50-29-3 Sigma-Aldrich 5.63

#values according to the OECD 121 guideline based on soil adsorption data
Acros Organics, Geel, Belgium
Merck, Darmstadt, Germany
Sigma-Aldrich, Steinheim, Germany


DETERMINATION OF RETENTION TIMES
Capacity factor (k’): k' = (tr - t0)/t0
where:
tr = retention time
t0 = mean column dead time


REPETITIONS
The reference substance and test item solutions were injected in duplicate. Blank solutions were analysed by single injection.

EVALUATION
- Calculation of capacity factors k':
- Calculation of retention times:
- Determination of the log Koc value:

Key result

Sample No.:

#1

Type:

log Kp

Value:

ca. 3.03 dimensionless

pH:

7

Remarks on result:

other: Result for peak 3

Key result

Sample No.:

#2

Type:

log Kp

Value:

ca. 3.71 dimensionless

pH:

7

Remarks on result:

other: Result for peak 6

Key result

Sample No.:

#3

Type:

log Kp

Value:

ca. 4.17 dimensionless

pH:

7

Remarks on result:

other: Result for peak 7

Key result

Sample No.:

#4

Type:

log Kp

Value:

4.81 dimensionless

pH:

7

Remarks on result:

other: Result for peak 11

Key result

Sample No.:

#5

Type:

log Kp

Value:

> 5.63 dimensionless

pH:

7

Remarks on result:

other: Result for peak 15

Key result

Sample No.:

#6

Type:

log Kp

Value:

> 5.63 dimensionless

pH:

7

Remarks on result:

other: Result for peak 19

Details on results (HPLC method):

The equation of the regression line was: log k’ = 0.327 x log Koc – 825 (r = 0.983, n = 16).
Multiple peaks with log Koc from 2.09 to > 5.63

K_ocof the test item

Substance	tr,1 [min]	tr,2 [min]	mean tr (n=2)	log Koc	Koc	Area %
Formamide (t0)	0.695	0.695	0.695
Acetanilide	0.921	0.922		1.26
Monuron	1.141	1.141		1.99
2,5-Dichloroaniline	1.315	1.313		2.55
Naphthalene	1.532	1.531		2.75
Benzoic acid phenylester	1.812	1.814		2.87
Fenthion	2.482	2.476		3.31
Phenanthrene	2.735	2.734		4.09
4,4’-DDT	6.945	6.957		5.63
TI206534-Peak3	1.707	1.710	1.709	3.03	1.1 x 10^3	34
TI206534-Peak6	2.392	2.396	2.394	3.71	5.2 x 10^3	15
TI206534-Peak7	3.085	3.090	3.088	4.17	1.5 x 10^4	16
TI206534-Peak11	4.552	4.564	4.558	4.81	6.4 x 10^4	7.0
TI206534-Peak15	12.206	12.208	12.207	> 5.63	> 4.3 x 10^5	6.7
TI206534-Peak19	12.784	12.784	12.784	> 5.63	> 4.3 x 10^5	6.8

Validity criteria fulfilled:

yes

Conclusions:

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of Formaldehyde, oligomeric reaction products with acetone and diphenylamine.
The Koc and log Koc values of the test item at neutral pH were:
Koc log Koc Area %
Test item – peak 3 1.1 x 10+3 3.03 34
Test item – peak 6 5.2 x 10+3 3.71 15
Test item – peak 7 1.5 x 10+4 4.17 13
Test item – peak 11 6.4 x 10+4 4.81 7.0
Test item – peak 15 > 4.3 x 10+5 > 5.63 6.7
Test item – peak 19 > 4.3 x 10+5 > 5.63 6.8

Executive summary:

The adsorption coefficient of the substance was estimated using the HPLC method based on soil-adsorption-reference data.

Multiple peaks with log K_oc from 2.09 to > 5.63 were obtained.

Description of key information

The adsorption coefficient was determined in accordance with OECD Guideline 121.

Multiple peaks with log K_oc from 2.09 to > 5.63 were obtained.

Key value for chemical safety assessment

Koc at 20 °C:

430 000

Additional information

Multiple peaks with log K_oc from 2.09 to > 5.63 were obtained.

[LogKoc: 5.63]