1-(3-Chloro-2-pyridinyl)-4,5-dihydro-3-[(phenylsulphonyl)oxy]-1H-pyrazole-5-carboxylic acid ethyl ester

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 2006 - December 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

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))

Version / remarks:

1992

Test guideline 2

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))

Version / remarks:

2001

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Test material

Test material information

Constituent 1

Reference substance name:

ethyl 3-[(benzenesulfonyl)oxy]-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate

EC Number:

846-153-4

Cas Number:

653592-41-7

Molecular formula:

C17H16ClN3O5S

IUPAC Name:

ethyl 3-[(benzenesulfonyl)oxy]-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate

Test material form:

solid

Radiolabelling:

no

Study design

Test temperature:

25ºC

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Agilent 1100 series Liquid Chromatograph, equipped with variable wavelength detector, auto sampler and PC based data system.
- Type, material and dimension of analytical (guard) column: Zorbax CN, 250 cm long, 0.46 cm i.d., 5 μm
- Detection system: VW detector

MOBILE PHASES
- Type: Methanol : Water, 55: 45 v/v
- Solutes for dissolving test and reference substances: Methanol: Water, 55:45 v/v

DETERMINATION OF DEAD TIME
- Method: by inert substance (sodium nitrate) which is not retained by the column

REFERENCE SUBSTANCES
- Identity: p-Toluamide, Methiocarb, Naphtalene, 1,2,3-Trichlorobenzene, Pyrazophos and Diclofop-methyl

DETERMINATION OF RETENTION TIMES
- Intervals of calibration: The calibration solution (mixture of six reference substances) was injected before and after the analysis of the test item and individual reference substances to check the performance of the instrument.

REPETITIONS
- Number of determinations: 3 for test item and 2 for reference and inert substances

EVALUATION
- Calculation of capacity factors k':
k’ = (tR-t0)/t0
where: tR = HPLC retention time of test and reference substances (minutes); t0 = HPLC dead time (minutes)
- Determination of the log Koc value:
The log k′ data of the reference substances were plotted against their log Koc values obtained in batch equilibrium experiments (published data, reference OECD 121, Table 3). Using this plot and the log k′ value of a test substance, the log Koc value of the test item was determined.

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Key result

Sample No.:

#1

Type:

log Koc

Value:

3.86

Adsorption coefficient 2

Key result

Sample No.:

#1

Type:

Koc

Value:

7 244.4

Results: HPLC method

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
4.050, 6.916, 8.398, 9.350, 13.675, and 15.770 minutes for p-Toluamide, Methiocarb, Naphthalene, 1,2,3-Trichlorobenzene, Pyrazophos, and Diclofop-methyl, respectively.
Analysis of the inert substance (sodium nitrate) provided a dead time analysis (t0) of 2.346 minutes.
- Details of fitted regression line (log k' vs. log Koc):
log Koc = 2.0969 + 2.4443 (log k′); correlation coefficient 0.9547
- Average retention data for test substance: 14.645 minutes

Applicant's summary and conclusion

Conclusions:

The Koc value for the test item was determined to be 7244.4 (log Koc = 3.86).

Executive summary:

This study was conducted to determine the adsorption coefficient of the test item according to OECD Guideline 121 and method EEC C.19.
The solutions of six reference substances (p-Toluamide, Methiocarb, Naphthalene, 1,2,3-Trichlorobenzene, Pyrazophos and Diclofop-methyl), inert substance (sodium nitrate) and test item were analyzed by HPLC equipped with a cyanopropyl column and a variable wavelength detector (271 nm) using methanol:water (55:45 v/v) as mobile phase. The mean retention times observed were 4.050, 6.916, 8.398, 9.350, 13.675, 15.770 and 14.645 minutes for p-Toluamide, Methiocarb, Naphthalene, 1,2,3-Trichlorobenzene, Pyrazophos, Diclofop-methyl and test item, respectively. The dead time (retention time for sodium nitrate) was 2.346 minutes for inert substance.

The calculated capacity factors (k′) were 0.7263, 1.9480, 2.5797, 2.9855, 4.8291, 5.7221 and 5.2425 for p-Toluamide, Methiocarb, Naphthalene, 1,2,3-Trichlorobenzene, Pyrazophos, Diclofop-methyl and test item, respectively.
The adsorption coefficient (Koc) of the test item was 7244.4 and the respective log Koc value was 3.86.