N-potassium phthalimide

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))

Principles of method if other than guideline:

To determine Adsorption coefficient (KOC) on soil and on sewage sludge of the N-potassium phthalimide (CAS No. 1074-82-4) using HPLC.

GLP compliance:

no

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Specific details on test material used for the study:

- Name of test material (as cited in study report): Potassium phthalimide
- Molecular formula (if other than submission substance): C8H5NO2.K
- Molecular weight (if other than submission substance): 185.223 g/mol
- Smiles notation (if other than submission substance): c12c(C(=O)[NH-]C1=O)cccc2.[K+]
- InChI: 1S/C8H5NO2.K/c10-7-5-3-1-2-4-6(5)8(11)9-7;/h1-4H,(H,9,10,11);/q;+1/p-1
- Substance type: Organic
- Physical state: solid

Radiolabelling:

not specified

Test temperature:

25°C

Details on study design: HPLC method:

The solutions of the test substance and reference substances were prepared in the mobile phase. Each of the reference substance and test substance were analysed by HPLC at 210 nm.
After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed.
Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor.
Operating Conditions:
HPLC Model No. : Agilent Technologies,1260 Infinity
Flow Rate : 1.0 mL/min
Column : ZORBAX Eclipse Plus C18, 4.6×100mm, 3.5 μm
Mobile phase : Acetonitrile: water (55:45)
Temperature : 25°C
Detector : Diode Array Detector @210nm
Injector : Autosampler
Injector volume : 10μl
Data Acquisition software : ChemStationOpen lab Control Panel

Details on test conditions:

A test item solution was prepared by accurately weighing 4 mg of test item and diluted with acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 8.16.

Key result

Type:

log Koc

Value:

1.855 dimensionless

pH:

8.16

Temp.:

25 °C

Remarks on result:

other: reported as 1.855 ± 0.001

Transformation products:

not specified

Test substance N-potassium phthalimide		K	Log k	Log Koc by Generalized Calibration Graph	Mean of Log Koc ± S.D.
tR1	1.276	0.439	-0.3579	1.8543	1.855 ± 0.001
tR2	1.277	0.440	-0.3568	1.8555

Validity criteria fulfilled:

yes

Conclusions:

The Adsorption Coefficient of test substance N-potassium phthalimide (CAS No. 1074-82-4)was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was found to be 1.855 ± 0.001 at 25°C.

Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge N-potassium phthalimide(CAS No.1074-82-4) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were having Koc value ranging from 1.25 to 4.09. The Log Koc value was found to be 1.855 ± 0.001at 25°C.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge N-potassium phthalimide(CAS No.1074-82-4) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were having Koc value ranging from 1.25 to 4.09. The Log Koc value was found to be 1.855 ± 0.001at 25°C.

Key value for chemical safety assessment

Koc at 20 °C:

71.614

Additional information

Three studies including experimental reports and Predicted model data of adsorption endpoint for the target chemical Potassium phthalimide (Cas no. 1074-82-4) with structurally similar read across were reviewed to summarize as follows:  

 

First experimental study by UERL laboratory;2017 suggest that the adsorption coefficient Koc in soil and in sewage sludge N-potassium phthalimide(CAS No.1074-82-4) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were having Koc value ranging from 1.25 to 4.09. The Log Koc value was found to be 1.855 ± 0.001at 25°C.

Above result supported by predicted model EPI suite 2017 indicate the soil adsorption coefficient (Koc) value of chemical Potassium phthalimide (Cas no. 1074-82-4) is estimated to be 109.2L/kg (log KOC = 2.038) by means of MCI method at 25 deg.C, indicating that it is has a low sorption to soil and sediment and therefore have moderate migration potential to groundwater.

And supporting data from HSDB database; 2017 for the read across chemical Phthalimide (Cas no. 85-41-6) indicated the Koc is estimated as approximately 100, using an experimental log Kow of 1.15 and a regression derived equation.This estimated Koc value suggests that phthalimide should have moderate to high mobility in soil.

Thus based on the above all available studies it is concluded that the test substance Potassium phthalimide (Cas no. 1074-82-4) has moderate to high mobility in soil/sediment.

[LogKoc: 1.855]