TOMILAC 214

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Recently conducted GLP compliant study using the most recent test methods

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

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

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): JKY-214
- Physical state: white solid
- Analytical purity: No information
- Lot/batch No.: Y002E
- Expiration date of the lot/batch: No information
- Stability under test conditions: No information. Assumed stable due to no data to the contrary
- Storage condition of test material: room temperature in the dark
- Other:

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

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus:
- Type: Agilent Technologies 1100, incorporating autosampler and workstation
- Type, material and dimension of analytical (guard) column: Zorbax SB CN 5pm (250 x 4.6 mm id)
- Column temperature: 40°C
- Detection system: UV
- Detector wavelength: dead time and reference standards: 210 nm; sample: 260 nm


MOBILE PHASES
- Type: methanol: water (55:45 v/v), adjusted with 0.1M hydrochloric acid
- Experiments with additives carried out on separate columns: no
- pH: 5.1
- Solutes for dissolving test and reference substances:
Test material (0.0201 g) was diluted to 100 ml with tetrahydrofuran
Solutions of reference standards were prepared in methanol.


DETERMINATION OF DEAD TIME
The dead time was determined by measuring the retention time of formamide (purity 99.94%, 622 mg/l solution in methanol).


REFERENCE SUBSTANCES
Standard Purity <%)* Concentration (mg/l)
Acetanilide 99+ 106
Phenol 99+ 106
Atrazine 97.2 102
Isoproturon 99.8 105
Triad i me nol 98.4 100
Linuron 99.7 100
Endosulfan-diol 99.8 115
Fenthion 97.8 103
a-Endosuifan 99.6 109
Phenanthrene 97.0 101
Diclofop-methyl 99.5 101
DDT 98.0 115



DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 5 microlitres
- Quantity of reference substances: 5 microlitres
- Intervals of calibration: minutes between 2 and 35 minutes


REPETITIONS
- Number of determinations: 2 injections for sample and standards


EVALUATION
- Calculation of capacity factors k': k = tr-to/ to
where k = capacity factor, tr = retention time (mins) and to = dead time (mins)
- Calculation of retention times: recorded in mins and retention time of standards plotted to form calibration curve
- Determination of the log Koc value: log Koc = log k - A/ B
where Koc is adsorption coefficient, k = capacity factor, A = intercept of calibration curve and B = slope of calibration curve

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

Koc

Value:

5.35

Adsorption coefficient 2

Type:

log Koc

Value:

218 000

Results: HPLC method

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
The retention times of formamide and the retention times, capacity factors (k) and logio Koc values for the reference standards are shown in the two following tables:

Dead Time Retention 1 fime (mins) Mean Retention Time (mins)
Injection 1 Injection 2
Formamide 2.825 2.824 2.825



Standard Retention Time (mins) Mean Retention Time (mins) Capacity Factor (k) Logio k Log™ Koc
Injection 1 Injection 2
Acetanilide 3.724 3.723 3.724 0.318 -0.497 1.25
Phenol 3.566 3.566 3.566 0.263 -0.581 1.32
Atrazine 5.096 5.096 5.096 0.804 -9.46 x10~2 1.81
Isoproturon 5.314 5.316 5.315 0.882 -5.47 x10~2 1.86
Triadimenol 6.680 6.679 6.680 1.37 0.135 2.40
Linuron 7.052 7.046 7.049 1.50 0.175 2.59
Endosulfan-dio! 8.099 8.096 8.098 1.87 0.271 3.02
Fenthion 10.150 10.149 10.150 2.59 0.414 3.31
a-Endosulfan 13.841 13.811 13.826 3.90 0.591 4.09
Phenanthrene 11.728 11.716 11.722 3.15 0.498 4.09
Diclofop-methyl 15.209 15.195 15.202 4.38 0.642 4.20
DDT 28.782 28.810 28.796 9.20 0.964 5.63


- Details of fitted regression line (log k' vs. log Koc):
Log10Koc Log10k
1.250 -0.497
1.320 -0.581
1.810 -9.463E-Q2
1.860 -5.466E-02
2.400 0;135
2.590 0,175
3.020 0.271
3.310 0.414
4.090 0.591
4.090 0.498
4.200 0.642
5.630 0.864
A = >0.773
B = 0.330
r = 0.967

- Graph of regression line attached
- Average retention data for test substance:

Any other information on results incl. tables

The retention times of formamide and the retention times, capacity factors (k) and log₁₀K_ocvalues for the reference standards are shown in the two following tables:

Formamide retention time Dead Time Retention time (mins) Mean Retention Time (mins) Injection 1 Injection 2 Formamide 2.825 2.824 2.825

 

 

Reference standards retention times Standard Retention Time (mins) Mean Retention Time (mins) Capacity Factor (k) Log10k Log10Koc Injection 1 Injection 2 Acetanilide 3.724 3.723 3.724 0.318 -0.497 1.25 Phenol 3.566 3.566 3.566 0.263 -0.581 1.32 Atrazine 5.096 5.096 5.096 0.804 -9.46 x10^-2 1.81 Isoproturon 5.314 5.316 5.315 0.882 -5.47 x10^-2 1.86 Triadimenol 6.680 6.679 6.680 1.37 0.135 2.40 Linuron 7.052 7.046 7.049 1.50 0.175 2.59 Endosulfan-diol 8.099 8.096 8.098 1.87 0.271 3.02 Fenthion 10.150 10.149 10.150 2.59 0.414 3.31 a-Endosulfan 13.841 13.811 13.826 3.90 0.591 4.09 Phenanthrene 11.728 11.716 11.722 3.15 0.498 4.09 Diclofop-methyl 15.209 15.195 15.202 4.38 0.642 4.20 DDT 28.782 28.810 28.796 9.20 0.964 5.63

Adsorption coefficient of sample

The retention times, capacity factors and log₁₀K_ocvalues determined for the sample are shown in the following table:

Injection Retention Time (mins) Capacity Factor (k) Log10k Log10Koc 1 30.250 9.71 0.987 5.33 2 30.395 9.76 0.990 5.34

 

Mean log₁₀K_oc:                    5.34

Adsorption coefficient: 2.18 x 10⁵

           

The method guideline states that the measurement of adsorption coefficient should be carried out on substances in their ionised and unionised forms. Testing was carried out at pH 5.1, with the test material in its non-ionised form and also attempted at a pH >9.24 in its ionised form. Analysis at the higher pH demonstrated drifting retention times indicative of damage caused to the stationary phase of the required column. Thus, only analysis performed in the non-ionised form was possible.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient (Koc) of the test material, in its non-ionised form, has been determined to be 21800, log10Koc5.34.

Executive summary:

The soil adsorption coefficient has been assessed using the HPLC method according to EU method C19 in compliance with GLP. The test system was calibrated using formamide and the adsorption coefficient determined by reference to 12 reference reagents of known adsorption coefficient. Measurements for the test material were recorded in duplicate and the adsorption coefficient calculated by reference to the calibration curve established from the reference solutions. The adsorption coefficient was determined for the substance in its non-ionised form at pH 5.1. The test was attempted at higher pH, >9.41 to obtain the result for the ionised form, but the raised pH was considered to damage the stationary phase of the required column. The adsorption coefficient was determined to be 5.34 at pH 5.1.