4-chlorophthalic anhydride

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

OECD Test Guideline 121 (2001) performed with hydrolysis product

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

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

GLP compliance:

yes

Type of method:

HPLC estimation method

Test material

Test material information

Constituent 1

Reference substance name:

4-chlorophthalic acid

EC Number:

201-886-3

EC Name:

4-chlorophthalic acid

Cas Number:

89-20-3

Molecular formula:

C8H5ClO4

IUPAC Name:

4-chlorophthalic acid

Details on test material:

4-Chlorophthalic acid (4-CLP acid; CAS #89-20-3), hydrolyzed from 4 Chlorophthalic anhydride (4-CLPA, CAS #118-45-6)

Study design

Test temperature:

25°C

HPLC method

Details on study design: HPLC method:

A 1.00 mg/mL 4-CLP acid stock solution was prepared by placing 0.0506 g of the test substance in a 50.0-mL volumetric flask and bringing it to volume with acetonitrile. This stock solution was divided into separate aliquots and stored refrigerated until injected on the instrument. A 1.00 mg/mL sodium nitrate reference standard stock solution was prepared by placing 0.00500 g of sodium nitrate in a 5.00-mL volumetric flask and bringing it to volume with acetonitrile. This stock solution was used to determine the dead time (t0) of the instrument, and was stored refrigerated until injected.

Reference standard stock solutions used in the determination of the Koc were prepared in acetonitrile using the following substances: acetanilide, aniline, benzoic acid phenylester, and phenanthrene.

HPLC method: Samples were analyzed by automated injection on a high performance liquid chromatographic system equipped with ultraviolet detection (HPLC/UV). The following instrumental conditions were utilized: Instrument: Hewlett Packard quaternary solvent pump Series 1100 equipped with a Hewlett Packard Series 1100 degasser and autosampler, a Hewlett Packard variable wavelength detector, a column heater and Hewlett Packard Version A.09.01 for data acquisition; Column: Zorbax SB-CN, 5-micrometers, 250 mm x 4.6 mm; Column Temperature: 25ºC; Mobile Phases: A: 100% 0.01 M sodium citrate tribasic; B: 100% acetonitrile; Flow Rate: 1.00 mL/minute; Injection Volume: 10.0 microL; and Wavelength: 210 nm. The dead time (t0) of the system was determined by making duplicate injections of sodium nitrate. Each remaining reference substance was analyzed in duplicate. A calibration graph was determined by plotting the log k’ versus corresponding log (Koc) for the reference substances.

The test substance was analyzed in duplicate. The capacity factor and log k’ were calculated and the log (Koc) determined from the calibration curve. The values of the log (Koc) from the duplicate measurement are considered acceptable when they fall within a range of +/ 0.25 log units.

Batch equilibrium or other method

Computational methods:

The adsorption distribution coefficient (Kd) is the ratio of the concentration of the test substance in the sewage sludge (Cs), and the concentration of the test substance in the aqueous phase (Caq) at the point of equilibrium. The adsorption coefficient (Koc) is the adsorption distribution coefficient (Kd) normalized with the organic carbon content of the sewage sludge (foc). The equations below show these relationships:

Kd = (Cs/Caq)

and

Koc= (Kd/foc)

where:
Cs is generally in units of microg/g and Caq is generally in units of microg/mL

The capacity factors (k’) for each reference standard compound with a known Koc value are determined by the equation:

k’=(tR-to)/to

where:
tR = the retention time of the test substance
to= the dead time (the average time a solvent molecule needs to pass through the column)

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

Koc

Value:

< 33.1 dimensionless

Adsorption coefficient 2

Type:

log Koc

Value:

< 1.52 dimensionless

Any other information on results incl. tables

Reference Standard Retention Times, Capacity Factors (k’), Log k’ and Log Koc Values

Sample Name	Retention Time (min)	k’	log k’	log Koc
Acetanilide	4.204	0.638	-0.195	1.52
Aniline	4.401	0.715	-0.146	1.74
Benzoic Acid Phenylester	7.967	2.104	0.323	3.26
Phenanthrene	9.684	2.773	0.443	4.35
Acetanilide	4.202	0.637	-0.196	1.52
Aniline	4.398	0.714	-0.147	1.74
Benzoic Acid Phenylester	7.938	2.093	0.321	3.26
Phenanthrene	9.645	2.758	0.441	4.35

Results of the Koc coefficient determination with 4-CLP acid

Sample Name	Retention Time (min)	k’	log k’	Calculated log Koc	Mean Log Koc	Koc	Mean Koc
4-CLP acid	2.494	less than -0.0282	NA*	less than 1.52	less than 1.52	less than 33.1	less than 33.1
4-CLP acid	2.496	less than -0.0275	NA	less than 1.52		less than 33.1
* NA=Not Applicable

Mathematical extrapolation of the Koc value for 4-CLP acid

Sample Name	Retention Time (min)	k’	log k’	Calculated log Koc	Mean Log Koc	Koc	Mean Koc
4-CLP acid	2.494	less than 0.0100	Less than -2.000	less than -6.13	less than -6.13	less than 7.4 x 10^-7	less than 7.4 x 10^-7
4-CLP acid	2.496	less than 0.0100	Less than -2.000	less than -6.13		less than 7.4 x 10^-7

Applicant's summary and conclusion

Conclusions:

The Koc for 4-CLP acid was determined to be <33.1, corresponding to a log Koc of <1.52.

Executive summary:

The adsorption / desorption potential of the substance was determined in an OECD 121 study that was in compliance with GLP criteria. The potential was measured according to the HPLC estimation method at a test temperature of 25 °C. The mathematical extrapolation of the Koc given the retention time of 4-CLP acid compared to the standards employed in the study was estimated to be -6.13. Since the retention time of 4-CLP acid was lower than the retention time for acetanilide (the earliest eluting calibration standard identified in the OECD 121 guidelines), the Koc for 4-CLP acid was reported as less than 33.1, the Koc of acetanilide (log Koc of 4-CLP acid is less than 1.52).