Octasodium 2-(8-(4-chloro-6-(3-((4-chloro-6-(3,6-disulfonato-2-(1,5-disulfonatonaphthalen-2-ylazo)-1-hydroxynaphthalen-8-ylamino)-1,3,5-triazin-2-yl)aminomethyl)phenylamino)-1,3,5-triazin-2-ylamino)-3,6-disulfonato-1-hydroxynaphthalen-2-ylazo)naphthalene-1,5-disulfonate

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 May 2000 to 17 October 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to OECD test guideline in compliance with GLP and reported with a GLP certificate.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

soil

Test material

Test material information

Constituent 1

Reference substance name:

Octasodium 2-(8-(4-chloro-6-(3-((4-chloro-6-(3,6-disulfonato-2-(1,5-disulfonatonaphthalen-2-ylazo)-1-hydroxynaphthalen-8-ylamino)-1,3,5-triazin-2-yl)aminomethyl)phenylamino)-1,3,5-triazin-2-ylamino)-3,6-disulfonato-1-hydroxynaphthalen-2-ylazo)naphthalene-1,5-disulfonate

EC Number:

413-550-5

EC Name:

Octasodium 2-(8-(4-chloro-6-(3-((4-chloro-6-(3,6-disulfonato-2-(1,5-disulfonatonaphthalen-2-ylazo)-1-hydroxynaphthalen-8-ylamino)-1,3,5-triazin-2-yl)aminomethyl)phenylamino)-1,3,5-triazin-2-ylamino)-3,6-disulfonato-1-hydroxynaphthalen-2-ylazo)naphthalene-1,5-disulfonate

Cas Number:

142068-96-0

Molecular formula:

Hill formula: C53H28Cl2N14Na8O26S8

IUPAC Name:

octasodium 5-[(4-chloro-6-{[4-({[4-chloro-6-({7-[2-(1,5-disulfonatonaphthalen-2-yl)diazen-1-yl]-8-hydroxy-3,6-disulfonatonaphthalen-1-yl}amino)-1,3,5-triazin-2-yl]amino}methyl)phenyl]amino}-1,3,5-triazin-2-yl)amino]-3-[2-(1,5-disulfonatonaphthalen-2-yl)diazen-1-yl]-4-hydroxynaphthalene-2,7-disulfonate

Details on test material:

- Name of test material (as cited in study report): H112339
- Analytical purity: 86.8%
The shipment of test item H 112339 (as Lot 321/18) was received on May 5, 2000 from BASF, Ludwigshafen, Germany, The Analytical Report "Characterization of "H 112339" before start of toxicological and ecotoxicological studies", Study no. 99 L 00180, BASF, specified the purity as 86.8 %. If not used for the preparation of stock solutions, the test item remained stored refrigerated, under nitrogen, in the dark at 4°C.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable.

Radiolabelling:

no

Study design

Test temperature:

20 °C

HPLC method

Details on study design: HPLC method:

Not applicable

Batch equilibrium or other method

Analytical monitoring:

yes

Details on sampling:

All samples taken were prepared and analysed according to the following steps:

Pre-incubation - Aliquots between 2 and 50 g of the standard soils were weighed in glass centrifuge tubes, equipped with a Teflon seal in the lid. A defined volume of 0.01 M CaCl2 (i.e. 49 ml) was added and the closed centrifuge tubes agitated at a setting of 150 rpm for 24 hours at 20 °C,

Fortification with H 112339 and Agitation - Following pre-incubation, if applicable, a defined volume of H 112339 stock solution, or analytical standard, was added (i.e. 1 ml) to adjust to the final volume (i.e, 50 ml) and concentration of the supernatant. The samples were agitated at 20°C at a setting of 150 rpm for predetennined time intervals between 2 and 24 hours.

Centrifugation - Following the agitation period, samples were collected and centrifuged at 2500 rpm and 4 °C for 10 min.

Filtration - Following the centrifugation, an aliquot of the supernatant was filtered through 0.45 ftm membrane filters into HPLC-vials prior to injection in the HPLC-system.

Details on matrix:

Two standard test soils, a Speyer 2.2 loamy Sand and a Speyer 2,3 sandy Loam were used throughout the study. The soils vary significantly in their physical characteristics, especially organic matter and pH.

The soils were received fieldfresh from the Agricultural Research Station Speyer, Germany on April 14, and May 15, 2000, respectively. The soils were received air-dried and sieved through a 2 mm sieve. Throughout the study, the soils were handled according to ISO norm 10381-6. Unless used for sample preparation, the soils were stored at approximately 4 ⁰C.

Details on test conditions:

PRELIMINARY STUDY
Throughout the study, the concentration decrease in the supernatant phase (indirect method) was used to determine adsorption and desorption of H 112339 to the test soils.

The optimal soil/solution ratio for the adsorption of H 112339 to the two test soils was determined at three soil/solution ratios. Duplicate samples of 2, 10 and 50 g of each soil and 49 ml 0.01 CaCl2 solution were pre-incubated according to the sample preparation procedure. After the preincubation, the samples were fortified with 1 ml of a 5.06 mg/ml standard of H 112339 to achieve an initial concentration of 0.10 mg/ml in the supernatant. Following a 24 h agitation period at 20 °C, centrifugation and filtration, the concentration of H 112339 in the supernatant was determined via HPLC-UV.

A control sample of 0.01 M CaCl, solution fortified with H 112339 and a control sample of 0.01 M CaCl2 solution and soil were subjected to the same procedure. The adsorption onto the surface of the test vessels was determined by analysing the control sample (H 112339 in 0.01 M CaCl2 solution) for a depletion of H 112339 concentration during the test procedure.

The stability of H 112339 during the test procedure was determined by reanalysing supernatants of duplicate samples of each soil at the end of the adsorption period (24 hours) and after an additional period of 19 days.

A parental mass balance was detemuned in duplicate experiments for both soils at soil/solution ratios that resulted in a depletion > 30% after 24 hours. These were 5g : 50 ml for Speyer 2.2, and 15g : 50 ml for Speyer 2.3 soil, respectively. Following the sample preparation steps until sample centrifugation, the aqueous phase was decanted and recovered as much as possible. The rernaining soil was extracted three times with 50 ml dimethyl sulfoxide (DMSO), and the extracts filtered and analysed. The amount of H112339 in aqueous supernatant and DMSO extracts was determined and integrated to establish the mass balance.

ADSORPTION KINETICS STUDY
The adsorption kinetics of H112339 to Speyer 2.2 and Speyer 2.3 standard test soil were determined based on the concentration, decrease in the supernatant phase (indirect method). The initial concentration level in the supernatant was 0.1 mg/ml. The same soil/solution ratios were used as in the preliminary study. Under the test conditions, the depletion of H 112339 in the supernatant after the adsorption phase exceeded 30% when 5g:50ml and 15g:50ml for test soils Speyer 2.2 and Speyer 2.3 were used.

Ten duplicate treated samples were prepared per timepoint and agitated for periods of 2,4,6,8 and 24 hours, respectively. Adsorption kinetics were determined based on the results obtained per contact time point.

Accurate determinations were possible as the values which result by multiplying the Kd determined for with the numerical value of the soil/solution ratio using the indirect method were > 0.3 for both test soils.

ADSORPTION ISOTHERMS, DESORPTION KINETICS AND ISOTHERMS

ADSORPTION ISOTHERMS
The Freundlich adsorption isotherms of H 112339 to Speyer 2.2 and Speyer 2.3 standard test soil were determined, since an accurate determination of Kd was possible based on the results of the Adsorption Kinetics Study.

Five duplicate assays per soil type were prepared in. a concentration range in the supernatant phase from 0.011 mg/ml to 0.505 mg/ml of H 112339. The adsorption isotherms study was performed similarly to the adsorption kinetics study, including the same soil/solution ratios, with the only difference that the aqueous phase was analysed only once after a period of 24 hours to ensure that the adsorption equilibrium was reached.

DESORPTION KINETICS
Desorption kinetics of H 112339 to Speyer 2.2 and Speyer 2.3 standard test soil were determined since an accurate detemination of Kd was possible based on the results from the Adsorption Kinetics Study.

Ten duplicate assays per soil type were prepared similarly to the adsorption kinetics study. The samples were agitated for a period of 24 hours to ensure that adsorption equilibrium was reached prior to commencing the desorption step. To determine the desorptlon of H 112339 from Speyer 2-2 and Speyer 2.3 standard test soil, the phases were separated by cenrrifugation and the supernatant removed as much as possible. The supernatant was replaced by 50 nil of 0.01 M CaCk. and the new mixtures agitated again to start the desorption phase. The supematants of duplicate samples were recovered and analysed for H 112339 after 2, 4, 6, 8, and 24 hours.

The percentage of desorption was calculated at each time point and plotted versus time.

DESORPTION ISOTHERMS
Desorption isotherms of H 112339 to Speyer 2.2 and Speyer 2.3 standard test soil were determined since an accurate determination of was possible based on the results from the Adsorption Kinetics Study.

Five duplicate assays per soil type were prepared in a concentration range from 0.011 mg/ml to 0.505 mg/ml of H 112339 in the supernatant phase. The desorption isotherms test was performed similarly to the desorption kinetics, with the only difference that the aqueous phase was analysed only once, after 24 hours of desorption to ensure that a desorption equilibrium was reached. The amount of H 112339 desorbed from the test soil was calculated based on the deteirrunafion of H 112339 in the resulting supernatant.

The content of H 112339 remaining adsorbed on soil at desorption equilibrium was plotted as a function of the equilibrium concentration of H 112339 in solution.

Duration of adsorption equilibration

Duration of adsorption equilibration 1

Duration:

2 h

Initial conc. measured:

101.1 other: ug/cm3 Speyer 2.2 & 2.3 Soil

Duration of adsorption equilibration 2

Duration:

4 h

Initial conc. measured:

101.1 other: ug/cm3 Speyer 2.2 & 2.3 Soil

Duration of adsorption equilibration 3

Duration:

6 h

Initial conc. measured:

101.1 other: ug/cm3 Speyer 2.2 & 2.3 Soil

Duration of adsorption equilibration 4

Duration:

8 h

Initial conc. measured:

101.1 other: ug/cm3 Speyer 2.2 & 2.3 Soil

Duration of adsorption equilibration 5

Duration:

24 h

Initial conc. measured:

101.1 other: ug/cm3 Speyer 2.2 & 2.3 Soil

Duration of desorption equilibration

Computational methods:

ADSORPTION ISOTHERMS

Freundlich adsorption isotherms were determined based on the results from the Adsorption Kinetics Study. Accurate determinations results by multiplying the Kd with the soil/solution ratio value to gain a value >0.3, when measurements are based on concentration decrease in the aqueous phase (indirect method), or >0.1, when both phases are analysed (direct method).

Five test item concentrations where used, covering two orders of magnitude, at the same soil/solution ratio per soi. The adsorption test was performed as in the Adsorption Kinetics Study, with the only difference that the aqueous phase will be analysed only once at the time necessary to reach equilibrium. The equilibrium concentrations in the solution will be determined and the amount adsorbed will be calculated from the depletion of the test item in the solution or with the direct method. The adsorbed mass per unit mass of soil will be plotted as a function of the equilibrium concentration of the test item


DESORPTION KINETICS

Desorption kinetics will be determined in soil experiments for which an accurate determination of Kd in the preceding adsorption kinetics study was possible.
Samples with the same soil/solution ratio where prepared for five time intervals at which it is desired to study the desorption kinetics. In every experiment (one soil, one solution) one blank is run that consists of the soil and 0.01 M CaCl2 solution, without test item, and of weight and volume, respectively, identical to those of the experiment.
As a control sample the test item in 0.01 M CaCl2 solution (without soil) was subjected to the same test procedure. All mixtures of the soil with the solution are agitated until adsorption equilibrium is reached. The phases are then separated by centrifugation and the aqueous phases removed as much as possible. The volume of solution removed will be replaced by an equal volume of 0.01 M CaCl2 without test item and the new mixtures will be agitated again. The aqueous phase of the first tube will be recovered as completely as possible and will be measured after, for example, 2 h, that of the second tube after 4 h, that of the third after 6 h, etc until the desorption equilibrium is reached.

The percentage desorption will be calculated at each time point (and/or time interval and plotted versus time. The desorption coefficient of at equilibrium was calculated. If the desorption. equilibrium is attained even within twice the time of the adsorption equilibrium, and the total desorption is more than 15% of the amount adsorbed , the adsorption is considered to be reversible.

DESORPTION ISOTHERMS

Desorption isotherms will be determined on the soils used in the adsorption isotherms experiment. The desorption test will be performed similarly to the desorption kinetics with the only difference that the aqueous phase was analysed only once, at desorption equilibrium. The amount of the test item desorbed was calculated. The content of test item remaining adsorbed on soil at desorption equilibrium was plotted as a function of the equilibrium concentration of the test item in solution

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

Koc

Value:

245.36

Temp.:

20 °C

Remarks on result:

other: Room temperature

Adsorption coefficient 2

Type:

log Koc

Value:

3.57

Temp.:

20 °C

Remarks on result:

other: Room temperature

Results: HPLC method

Details on results (HPLC method):

Not applicable

Results: Batch equilibrium or other method

Adsorption and desorption constants:

The Freundlich adsorption coefficients Kadsf were determined for Speyer 2.2 and Speyer 2.3 to be 93.9 and 29.8, respectively. The amount of H 112339 desorbed in the desorption kinetics study ranged from 26.3 to 37.3 and 28.0 to 42.2 % in Speyer 2.2 and Speyer 2.3 soils, respectively. The adsorption process can be considered irreversible. The Freundlich desorption coefficient Kdesf in Speyer 2.2 and Speyer 2.3 soils were calculated based on results of a desorption isotherms study to be 1.35*10-7 and 3.73*10-9 respectively.

Recovery of test material:

See below in Table 7 "determination of the parental mass balance" for recovery details.

Concentration of test substance at end of adsorption equilibration period:

See below in Table 8 "results of the adsorption kinetics study" for recovery details.

Concentration of test substance at end of desorption equilibration period:

See below in Table 10 "results of the desorption kinetics study" for recovery details.

Mass balance (%) at end of adsorption phase

Duration:

24 h

% Adsorption:

90 - 110

Transformation products:

not measured

Details on results (Batch equilibrium method):

ADSORPTION KINETICS STUDY OF H112339
In both soils the adsorption equilibrium of-H 112339 was already reached after 2 hours. The percentage of adsorption ranged from 25.8 % to 36.0 % and 22.4 to 34.7 % for the two soil types, the average adsorption coefficient (Kd) and the average adsorption coefficient based on organic carbon content (K0) were determined as 3.57 and 245.36, respectively. The average log Koc. was determined to be 2.39 for the two soils. The results demonstrate that H 112339 is weakly absorbed to soil.

ADSORPTION ISOTHERMS STUDY OF H 112339
The Freundlich adsorption coefficients K"*F were determined for Speyer 2.2 and Speyer 2.3 to be 93.9 and 29.8, respectively. The respective regression constants n were 2.873 and 3.012 for Speyer 2.2 and Speyer 2.3 soil.

DESORPTION KINETICS STUDY OF H 112339
The amount of H 112339 desorbed reached a maximum of 37.3 % (after 6 h) in Speyer 2.2 and 42.2 % (after 8 h) in Speyer 2.3 soil, respectively. With less than 75 % of H 112339 desorbed at any timing, the adsorption process can be considered irreversible.

DESORPTION ISOTHERMS STUDY OF H 112339
The Freundlich desorption coefficient KflesF of H 112339 from Speyer 2.2 and Speyer 2.3 soils were calculated to 1.35*10-7 and 3.73*l0-7, respectively. The respective regression constants n were 0.3 and 0.2 for Speyer 2.2 and Speyer 2.3 soil.

Statistics:

As discussed above and within the tables below.

Any other information on results incl. tables

 TABLE 7:   DETERMINATION OF THE PARENTAL MASS BALANCE

 

SPEYER. 2.2 SOIL

 

 

Sample Name	Initial Concentration Test Solution [ug/cm3]	Total Amount Test item [ug]	Amount Determined in. Test Solution [ug]	Amount Determined in First Extraction [ug]	Amount Determined in Second Extraction [ug]	Amount Determined in Third Extraction [ug]	Overall Amount Determined [%]	Overall Recovery [%]
BA-0147	101.1	5056.9	3235.0	1090.0	175.0	85.0	4585.0	90.7
BA-0148	101.1	5056.9	3315.0	1030.0	155.0	75.0	4575.0	90.5

* 50ml DMSO, soil solution ratio 0.1 (5g:50ml)

 

 SPEYER 2.3 SOIL

 

Sample Name	Initial Concentration Test Solution [ug/cm3]	Total Amount Test item [ug]	Amount Determined in. Test Solution [ug]	Amount Determined in First Extraction [ug]	Amount Determined in Second Extraction [ug]	Amount Determined in Third Extraction [ug]	Overall Amount Determined [%]	Overall Recovery [%]
BA-0134	101.1	5056.9	3910.0	475.0	90.0	90.0	4565	90.3
BA-0135	101.1	5056.9	3955.0	495.0	70.0	155.0	4675	92.4

* 50ml DMSO, soil solution ratio 0.3 (15g:50ml)

 

 

TABLE 8: RESULTS OF THE ADSORPTION KINETICS STUDY

 

SPEYER 2.2 SOIL

 

Sample Name	Soil Speyer 2.2 [g]	Soil Solution Ratio	Time Interval [g]	Initial Concentration Test Solution [ug/cm^3]	Residual Concentration Test Solution [ug/cm^3]	Adsorption at Time ti %	KD at Time ti (cm^3g-l]
BA-0139	5	0.1	2	101.1	73.5	27.3	3.76
BA-0140	5	0.1	2	101.1	74.8	26.0	3.52
BA-0141	5	0.1	4	101.1	75.0	25.S	3,49
BA-0142	5	0.1	4	101.1	73.9	26.9	3.69
BA-0143	5	0.1	6	101.1	73.9	26:9	3.69
BA-0144	5	0.1	6	101.1	73.6	27.2	3.74
BA-G145	5	0.1	8	101.1	71.9	28.9	4.07
BA-0146	5	0.1	8	101.1	72.7	28.1	3.91
BA-0147	5	0.1	24	101.1	64.7	36.0	5.63
BA-0148	5	0.1	24	101.1	66.3	34.4	5.25

 

 SPEYER2.3SOIL

 

Sample Name	Soil Speyer 2.2 [g]	Soil Solution Ratio	Time Interval [g]	Initial Concentration Test Solution [ug/cm^3]	Residual Concentration Test Solution [ug/cm^3]	Adsorption at Time ti %	KD at Time ti (cm^3g-l]
BA-0149	15	0.3	2	101.1	77.9	23.0	0.99
BA-0150	15	0,3	2	101.1	7S.5	22.4	0.96
BA-0151	15	0.3	4	101.1	76.6	24.3	1.07
BA-0152	15	0,3	4	101.1	73.7	27.1	1.24
BA-0153	15	0.3	6	101.1	75.4	25.4	1.14
BA-0154	15	0.3	6	101.1	73.7	27,1	1.24
BA-0155	15	0.3	8	101.1	71.4	29.4	1.39
BA-0156	15	0.3	8	101.1	72.7	28.1	1.31
BA-0157	15	0.3	24	101.1	66.0	34.7	1.77
BA-0158	15	0.3	24	101.1	67.9	32.9	1.63

 

 

TABLE 10: RESULTS OF THE DESORPTION KINETICS STUDY

 

Speyer 2.2 Soil

 

Sample Name	Amount Test Item [ug/test tube]	Time Interval for Adsorption [hr.]	Mass of Test Item Adsorbed [ug]	Time Interval for Desorption [hr.]	Residual Concentration Test Solution [ug/cm^3]	Mass of Test Item Desorbed [ug]	Resorption at Time ti [%]
BA-0159	5'056	24	2091.0	2	13.7	685.0	32.8
BA-0160	5'056	24	2136.0	2	12.8	640.0	30.0
BA-0161	5'056	24	2021.0	4	12.2	610.0	30.2
BA-0162	5'056	24	1836.0	4	10.7	535.0	29.1
BA-0163	5'056	24	1676.0	6	12.5	625.0	37.3
BA-0164	5-056	24	1926.0	6	13.1	655.0	34.0
BA-0165	5'056	24	2006,0	S	12.9	645.0	32.2
BA-0166	5'056	24	1911.0	8	12.7	635.0	33.2
BA-0167	5'056	24	1996.0	24	10.5	525.0	26.3
BA-0168	5'056	24	1996.0	24	10.5	540.0	27.1

 

Speyer 2.3 Soil

 

Sample Name	Amount Test Item [ug/test tube]	Time Interval for Adsorption [hr.]	Mass of Test Item Adsorbed [ug]	Time Interval for Desorption [hr.]	Residual Concentration Test Solution [ug/cm^3]	Mass of Test Item Desorbed [ug]	Resorption at Time ti [%]
BA-0169	5'056	24	1886.0	2	12.4	620.0	32.9
BA-0170	5'056	24	1871.0	2	12.9	645.0	34.5
BA-0171	5'056	24	1806.0	4	13.0	650.0	36.0
BA-0I72	5'056	24	1756.0	4	13.3	665.0	37.9
BA-0173	5'056	24	1720.8	6	12.3	615.0	35.7
BA-0174	5'056	24	1781.0	6	12.3	615.0	34.5
BA-0175	5'056	24	1576.0	S	13,3	665.0	42.2
BA-0176	5'056	24	1781.0	S	13.2	660.0	37.1
BA-0177	5'056	24	1786.0	24	10.0	500.0	28.0
BA-0178	5'056	24	1716.0	24	11.6	580.0	33.8

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The average values of 3.57 and 245.36 indicate that H 112339 is weakly adsorbed to soil. The adsorption process can be considered irreversible.

Executive summary:

Sttudy conducted to OECD test guideline 106 in compliance with GLP and reported with a GLP cerificate.

The adsorption characteristics of the test item H 112339 from a 0.01 M CaCl2. solution to Speyer 2.2 loamy Sand and Speyer 2.3 sandy Loam standard test soils was studied. The averaged adsorption coefficient Koc and the adsorption coefficient based on organic carbon content K,were determined to be 3.57 and 245.36, respectively. The results indicate that H 112339 is weakly adsorbed to soil. This is expected, given the high water solubility and other partitioning values for the substance.