Potassium hydrogen phthalate

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

Justification for type of information:

Experimental test result performed using standard test guidelines

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 test chemical Potassium hydrogen phthalate (CAS no. 877-24-7) 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: Potassium hydrogen phthalate
- Molecular formula: C8H5KO4
- Molecular weight: 204.221 g/mol
- Smiles notation: c1(c(cccc1)C(=O)[O-])C(O)=O.[K+]
- InChl: 1S/C8H6O4.K/c9-7(10)5-3-1-2-4-6(5)8(11)12;/h1-4H,(H,9,10)(H,11,12);/q;+1/p-1
- Substance type: Organic
- Physical state: Solid
- Batch No./ Lot no.: 0051
- Physical Appearance: white crystalline powder
- Purity: 100.3%
- Stability: Stable in recommended storage conditions
- Storage Conditions: Ambient Temp (23 to 27 deg.C) (Store in a cool, dry, well ventilated place. Keep in a fireproof place. Keep away from strong bases, strong acids, sources of heat, ignition and direct sunlight)

Radiolabelling:

no

Test temperature:

25°C

Details on study design: HPLC method:

HPLC Procedure:
The solutions of the test substance and reference substances were prepared in solvent mentioned in 4.3. 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(table 3).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 : 1.0ml/min
Column : ZORBAX Eclipse Plus C18, 4.6×100mm, 3.5 μm
Mobile phase : ACN : water (55:45)
Temperature : 25°C
Detector : Diode Array Detector @210nm
Injector : Autosampler
Injector volume : 10μl
Data Acquisition software : ChemStationOpen lab Control Panel

Analytical monitoring:

not specified

Details on sampling:

- Concentrations: 400 mg/l
- Sampling interval: 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 5.4.

Key result

Sample No.:

#1

Type:

log Koc

Value:

0.841 dimensionless

pH:

5.4

Temp.:

25 °C

Remarks on result:

other: Log Koc = 0.841± 0.000

Details on results (HPLC method):

The Adsorption coefficient (KOC) on soil and on sewage sludge of the Potassium hydrogen phthalate (CAS No. 877-24-7) was determined to be 0.841± 0.000 at 25°C.

Transformation products:

not specified

Test substance		K	Log k	Log Koc by Generalized Calibration Graph	Mean of Log Koc ± S.D.
tR1	0.854	-0.037	-1.429	0.841	0.841 ±0.000
tR2	0.854	-0.037	-1.429	0.841

Validity criteria fulfilled:

yes

Conclusions:

The Adsorption Coefficient of test substance Potassium hydrogen phthalate (CAS No. 877-24-7) was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined to be 0.841± 0.000 at 25°C..

Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge of test chemical Potassium hydrogen phthalate (CAS No. 877-24-7) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. 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 5.4. 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. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were Acetanilide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4-

Nitrobenzamide, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, 3,5-dinitrobenzamide, Benzamide, phenanthrene having Koc value ranging from 1.25 to 4.09. The Log Koc value of test chemical Potassium hydrogen phthalate was determined to be 0.841± 0.000 at 25°C. This log Koc value indicates that the substance Potassium hydrogen phthalate has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge of test chemical Potassium hydrogen phthalate (CAS No. 877-24-7) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals (Experimental study report, 2018). The solutions of the test substance and reference substances were prepared in appropriate solvents. 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 5.4. 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. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were Acetanilide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4- Nitrobenzamide, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichloro benzene, Pentachlorophenol, 3,5-dinitrobenzamide, Benzamide, phenanthrene having Koc value ranging from 1.25 to 4.09. The Log Koc value of test chemical Potassium hydrogen phthalate was determined to be 0.841± 0.000 at 25°C. This log Koc value indicates that the substance Potassium hydrogen phthalate has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:

6.934

Additional information

The adsorption coefficient Koc in soil and in sewage sludge of test chemical Potassium hydrogen phthalate (CAS No. 877-24-7) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals (Experimental study report, 2018). The solutions of the test substance and reference substances were prepared in appropriate solvents. 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 5.4. 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. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were Acetanilide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4- Nitrobenzamide, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichloro benzene, Pentachlorophenol, 3,5-dinitrobenzamide, Benzamide, phenanthrene having Koc value ranging from 1.25 to 4.09. The Log Koc value of test chemical Potassium hydrogen phthalate was determined to be 0.841± 0.000 at 25°C. This log Koc value indicates that the substance Potassium hydrogen phthalate has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

[LogKoc: 0.841]