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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 OECD 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:
Reverse Phase High Performance Liquid Chromatography on Octadecyl-modified silica based stationary phase is used.
Partitioning on the column occurs in order of hydrophobicity when a suitable mobile phase is used. From relationship between the measured retention times and the adsorption coefficient on organic matter of reference substances, the sorption coefficient of the test substance is calculated.
GLP compliance:
yes
Type of method:
HPLC estimation method
Media:
soil/sewage sludge
Specific details on test material used for the study:
- Name of test material: Ammonium iodide
- IUPAC name: Ammonium iodide
- Molecular formula: H4IN
- Molecular weight: 144.939 g/mole
- Smiles : [NH4+].[IH-]
- Inchl: 1S/HI.H3N/h1H;1H3
- Substance type: Inorganic
- Physical state: Solid crystalline powder (colorless to white)
Radiolabelling:
not specified
Test temperature:
25 deg.C
Details on study design: HPLC method:
PREPARATION PROCEDURE
Preparation of Reference substances:
Twenty eight reference substances Acetanilide, 2-nitrobenzamide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 3-nitrobenzamide, Nitrobenzene, 4-Nitrobenzamide, 1-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, N,Ndimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene were chosen having Koc value range from 1.25 to 4.09. Individual solutions of these twenty eight substances were prepared in Acetonitrile with concentrations of 500 mg/l.
Urea (at concentration of 500 mg/l) was used as an unretained compound for the determination of the “dead
time” t0.
K=tR -t0
t0
where
k= capacity factor,
tR= retention time of test substance and reference substance.
t0=retention time of Urea.
Analytical monitoring:
yes
Details on sampling:
A test item solution was prepared by accurately weighing 3 mg of test item and diluted with methanol up to 10 ml. Thus, the test solution concentration was 300 mg/l. The pH of test substance was 6.71.
Details on test conditions:
Chromatographic 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 : Acetonitrile : water (55:45)
Temperature : 25°C
Detector : Diode Array Detector @210nm
Injector : Autosampler
Injector volume : 10μl
Data Acquisition software : ChemStationOpen lab Control Panel
Key result
Sample No.:
#1
Type:
log Koc
Value:
1.275 dimensionless
Temp.:
25 °C
Remarks on result:
other: other details not available
Details on results (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(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.
Transformation products:
not specified

The Log Kocof ammonium Iodide (CAS No. 12027 -06 -4) was determined to be 1.275 dimensionless at 25°C.

Test substance ammonium Iodide

 

K

Log k (X axis)

Log Koc ( Y axis)

 By Generalized calibration graph

Mean of Log Koc± S.D

Rt1

 

0.782

-0.118

-0.927

1.269

1.275± 0.009

 

Rt2

 

0.779

-0.122

-0.914

1.281

Validity criteria fulfilled:
not specified
Conclusions:
The Adsorption Coefficient of test substance Ammonium iodide (CAS No.12027-06-4) was determined as per the HPLC method. The Log Koc value obtained was 1.275 dimensionless at 25°C.
Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge Ammonium iodide (CAS No. 12027 -06 -4) was determined by the Reverse Phase High Performance Liquid Chromatographic method. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared.

The reference substances have Koc value ranging from 1.25 to 4.09. The Log Koc value of test chemical Ammonium iodide was determined to be 1.275 dimensionless at 25°C. Based on the value of log Koc it is concluded that this test chemical has negligible sorption to soil and sediments and therefore has rapid migration potential to ground water.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludgeAmmonium iodide (CAS No. 12027 -06 -4) was determined by the Reverse Phase High Performance Liquid Chromatographic method. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared.

The reference substances have Koc value ranging from 1.25 to 4.09.The Log Koc value of test chemicalAmmonium iodidewas determined to be 1.275 dimensionless at 25°C. Based on the value of log Koc it is concluded that this test chemical has negligible sorption to soil and sediments and therefore has rapid migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:
18.8

Additional information

The adsorption coefficient Koc in soil and in sewage sludgeAmmonium iodide(CAS No. 12027 -06 -4) was determined by the Reverse Phase High Performance Liquid Chromatographic method. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared.

The reference substances have Koc value ranging from 1.25 to 4.09.The Log Koc value of test chemicalAmmonium iodidewas determined to be 1.275 dimensionless at 25°C. Based on the value of log Koc it is concluded that this test chemical has negligible sorption to soil and sediments and therefore has rapid migration potential to ground water.

[LogKoc: 1.275]