Reaction products of bis(4-methylpentan-2-yl)dithiophosphoric acid with phosphorus oxide, propylene oxide and amines, C12-14-alkyl (branched)

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:

May 5 - May 13, 2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was performed according to guideline. Restriction due to log Koc range of test material was outside the range of the calibration standards.

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)

Remarks:

Issued by: The Department of Health of the Government of the United Kingdom Inspection date: 19 August 2008 Signed by: Dr. Andrew J. Gray, Head, UK GLP Monitoring Authority

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

30 C

Details on study design: HPLC method:

EQUIPMENT

- Apparatus: Agilent Technologies 1050

- Type: HPLC

- Type, material and dimension of analytical (guard) column: Zorbax SB-CN 5 μm (250 x 4.6 mm id)
- Detection system: UV 210 nm



MOBILE PHASES

- Type: methanol:reverse osmosis water (55:45 v/v), adjusted to pH 7.0 with 0.1M NaOH

- pH: 7.0

- Solutes for dissolving test and reference substances: methanol


DETERMINATION OF DEAD TIME

- Method: by inert substances which are not retained by the column

REFERENCE SUBSTANCES ( % purity and concentrations shown in Table 1)

- Identity: Acetanilide, Phenol, Atrazine, Isoproturon, Triadimenol, Linuron, Endosulfan-diol, Fention, a-Endosulfan, Phenanthrene, Diclofop-methyl, DDT

DETERMINATION OF RETENTION TIMES

- Quantity of test substance introduced in the column: 10μl of 0.106g/100 mL methanol

- Quantity of reference substances: 10μl of 1g/L solutions in methanol:RO water (55:45 v/v)


REPETITIONS

- Number of determinations: duplicate


EVALUATION

- Calculation of capacity factors k': calculated from the dead time and retention times of reference standards as described in guideline.

- Calculation of retention times: Dead time for formamide (shown in Table 2) and retention times for standards and test material (shown in Table 3 and Table 4).

- Determination of the log Koc value: determined from a calibration plot of log k' vs. log Koc as described in guideline. Log k1 and log Koc are shown in Table 4. Calibration graph is attached in Figure 1.

Type:

log Koc

Value:

< 1.25

Remarks on result:

other: 67.7 area %

Type:

log Koc

Value:

>= 1.36 - <= 5.09

Remarks on result:

other: 32.4 area %

Details on results (HPLC method):

The test substance is a mixture of several components with log Koc values ranging from < 1.25 to 5.09

- Retention times of reference substances used for calibration (shown in Table 3):

- Details of fitted regression line (log k' vs. log Koc): R2=0.968; slope = 0.357; intercept = -0.740

- Graph of regression line attached: Yes (Figure 1)

- Average retention data for test substance: multiple components resolved by HPLC with retention times ranging from 2.043 to 36.982 minutes. See table 5.

Table 2: Determination of Dead Time (formamide)

Substance	Retention Time (min)		Dead Time (min)
	Injection 1	Injection 2
Formamide	2.864	2.861	2.8625

Table 3: Retention times, capacity factor and adsorption coefficients of Reference Standards

Reference Standard	Mean Retention Time (min.)	Capacity factor(k)	Log k	Log Koc
Acetanilide	3.913	0.367	-0.435	1.25
Phenol	3.716	0.298	-0.525	1.32
Atrazine	5.609	0.959	-.00180	1.81
Isoproturon	5.928	1.7	.0297	1.86
Triadimenol	7.881	1.75	0.244	2.40
Linuron	8.331	1.91	0.281	2.59
Endosulfan-diol	9.828	2.43	0.386	3.02
Fenthion	13.182	3.61	0.557	3.31
a-Endosulfan	17.974	5.28	0.723	4.09
Phenanthrene	14.997	4.24	0.627	4.09
Diclofop-methyl	20.809	6.27	0.797	4.20
DDT	42.279	13.8	1.14	5.63

Regression line: slope = 0.357 intercept = -0.740 R² = 0.968

Table 4. Retention times, capacity factors and adsorption coefficient (log Koc) for test material

Peak number	Injection	Retention time (min)	Capacity factor, k	log K	logKoc	Mean log Koc	% area
1	1	2.043	-0.286	-	< 1.25	< 1.25	55.6
	2	2.046	-0.285	-	< 1.25
2	1	3.848	0.344	-0.463	< 1.25	< 1.25	12.1
	2	3.833	0.339	-0.470	< 1.25
3	1	4.461	0.558	-0.253	1.37	1.36	10.5
	2	4.437	0.550	-0.260	1.35
4	1	5.326	0.860	-0.065	1.89	1.92	8.00
	2	5.419	0.893	-0.0493	1.94
5	1	6.962	1.43	0.156	2.51	2.51	0.423
	2	6.943	1.43	0.154	2.51
6	1	7.269	1.54	0.187	2.60	2.60	0.63
	2	7.249	1.53	0.185	2.60
7	1	7.832	1.74	0.239	2.75	2.75	1.12
	2	7.799	1.72	0.237	2.74
8	1	10.534	2.68	0.428	3.28	3.28	1.89
	2	10.534	2.68	0.428	3.28
9	1	11.43	2.99	0.476	3.41	3.41	3.13
	2	11.337	2.96	0.471	3.40
10	1	12.019	3.20	0.505	3.49	3.49	1.14
	2	11.903	3.16	0.499	3.48
11	1	36.982	11.92	1.08	5.09	5.09	5.54
	2	36.557	11.77	1.07	5.08

Validity criteria fulfilled:

yes

Remarks:

A plot of log k vs log Koc for reference standards gave an R2 value of 0.968

Conclusions:

The log Koc determined for the test material ranged from <1.25 to 5.09

Executive summary:

The adsorption coefficient of the test material was determined by HPLC following the guidelines in EU Method C.19. The test substance is a mixture of components with log Koc values ranging from < 1.25 to 5.09.

Description of key information

The test substance is a mixture of components with log Koc values ranging from < 1.25 to 5.09 (EU Method C.19)

Key value for chemical safety assessment

Koc at 20 °C:

17.7

Additional information

The adsorption coefficient of the test material was determined by HPLC following the guidelines in EU Method C.19. The test substance is a mixture of components with log Koc values ranging from < 1.25 to 5.09.