1,3-bis(1-isocyanato-1-methylethyl)benzene

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

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:

other: HPLC column

Radiolabelling:

no

Test temperature:

30°C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Agilent Technologies11 00, incorporating autosampler and workstation
- Type, material and dimension of analytical (guard) column: Column: CN Optimal 5µ (150 x 4.6 mm id); Column temperature: 30°C
- Detection system: UV detector at 210 nm wavelength

MOBILE PHASES
- Type: Methanol:water (55:45 v/v)
- pH: 6.5
- Flow rate: 1.0 mL/min

DETERMINATION OF DEAD TIME
- Method: by inert substance (formamide) which are not retained by the column

REFERENCE SUBSTANCES
- Identity: Acetanilide at 108 mg/L; Phenol at 104 mg/L; Atrazine at 96 mg/L; Isoproturon at 98 mg/L; Triadimenol at 100 mg/L; Linuron at 99 mg/L; Naphthalene at 109 mg/L; Endosulfan-diol at 101 mg/L; α-Endosulfan at 126 mg/L; Phenanthrene at 101 mg/L; Diclofop-methyl at 104 mg/L; DDT at 101 mg/L
- Solvent used for reference substance: Acetonitrile

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 10µL (test solution preparation: 0.1085 g of test material was diluted to 100 mL with acetonitrile and further diluted by a factor 4)
- Quantity of reference substances: See above under reference substances
- Intervals of calibration: Ten

REPETITIONS
- Number of determinations: Two

EVALUATION
- Calculation of capacity factors k: The capacity factor was determined using: k = (tr-t0)/t0; where, k: Capacity factor; tr: retention time (min); t0: dead time (min)
- Determination of the log Koc value: The adsorption coefficient was calculated using: Log10Koc= (Log10 k-A)/B; where, Koc: adsorption coefficient; k: capacity factor; A: intercept of the calibration curve; B: slope of the calibration curve

Analytical monitoring:

not required

Details on sampling:

Not applicable

Details on matrix:

Not applicable

Details on test conditions:

Not applicable

Initial conc. measured:

other: Not applicable

Computational methods:

Not applicable

Type:

Koc

Value:

11 400

Temp.:

30 °C

Remarks on result:

other: HPLC method: % organic carbon not relevant

Type:

log Koc

Value:

4.06

Temp.:

30 °C

Remarks on result:

other: Mean value. HPLC method; % organic carbon not relevant

Details on results (HPLC method):

For details, see 'Any other information on results incl. tables'

Adsorption and desorption constants:

Not applicable

Recovery of test material:

Not applicable

Concentration of test substance at end of adsorption equilibration period:

Not applicable

Concentration of test substance at end of desorption equilibration period:

Not applicable

Transformation products:

not measured

Details on results (Batch equilibrium method):

Not applicable

Statistics:

Not applicable

Table 1: Retention times of formamide

Dead Time	Retention Time (min)	Mean Retention Time (min)	Mean Retention Time (min)
	Injection 1	Injection 2
Formamide	1.951	1.948	1.95

Table 2: Retention times, capacity factors (k) and log10 Koc values for the reference standards

Standard	Retention Time (min)		Mean Retention Time (min)	Capacity Factor (k)	LOG10 k	LOG10 Koc
	Injection 1	Injection 2
Acetanilide	2.526	2.526	2.526	0.296	-0.529	1.25
Phenol	2.596	2.598	2.597	0.332	-0.479	1.32
Atrazine	2.956	2.963	2.96	0.518	-0.286	1.81
Isoproturon	3.256	3.258	3.257	0.671	-0.173	1.86
Triadimenol	3.97	3.968	3.969	1.04	1.53 x 10-2	2.4
Linuron	4.645	4.629	4.637	1.38	0.139	2.59
Naphthalene	4.317	4.309	4.313	1.21	8.36 x 10-2	2.75
Endosulfan-diol	5.783	5.761	5.772	1.96	0.292	3.02
α-Endosulfan	8.334	8.335	8.335	3.28	0.515	4.09
Phenanthrene	7.214	7.211	7.213	2.7	0.431	4.09
Diclofop-methyl	8.284	8.28	8.282	3.25	0.512	4.2
DDT	16.325	16.348	16.337	7.38	0.868	5.63

Table 3: Retention times, capacity factors and log10 Koc values determined for the test material

Injection	Retention Time (min)	Capacity Factor (k)	Log10 k	Log10 Koc
1	7.747	2.97	0.473	4.06
2	7.743	2.97	0.473	4.06

Validity criteria fulfilled:

yes

Conclusions:

Under the test conditions, the adsorption coefficient (Koc) of m-TMXDI was determined to be 1.14 x 10(4); log10 Koc = 4.06.

Executive summary:

An adsorption coefficient (Koc) on soil and sewage sludge was determined for m-TMXDI using the HPLC screening method according to OECD Guideline 121 and EU Method C.19, in compliance with GLP.The test substance (10 µL), dead time (formamide) and reference standard solutions were injected in duplicate into the HPLC columns. The retention time data of the deadtime and reference standard solutions were then used to construct the calibration curve. Based on this curve, the log Koc value of the test substance was determined. Under the study conditions, the adsorption coefficient (Koc) of m-TMXDI was determined to be 1.14 x 10(4) and the log10 Koc was 4.06 (Fox, 2009).

Key value for chemical safety assessment

Koc at 20 °C:

11 400

Additional information

An adsorption coefficient (Koc) on soil and sewage sludge was determined for m-TMXDI using the HPLC screening method according to OECD Guideline 121 and EU Method C.19, in compliance with GLP. The test substance (10 µL), dead time (formamide) and reference standard solutions were injected in duplicate into the HPLC columns. The retention time data of the deadtime and reference standard solutions were then used to construct the calibration curve. Based on this curve, the log Koc value of the test substance was determined. Under the study conditions, the adsorption coefficient (Koc) of m-TMXDI was determined to be 1.14 x 10(4) and the log10 Koc was 4.06 (Fox, 2009).