Phenoxymethylpenicillin potassium

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)

Version / remarks:

version adopted 21st January 2000

Qualifier:

according to guideline

Guideline:

EU Method C.18 (Adsorption / Desorption Using a Batch Equilibrium Method)

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

soil

Specific details on test material used for the study:

Name: Pen V Potassium
Lot No.: B519322
Appearance: white, solid powder
Expiry date: 30 April 2024
Storage condition: at room temperature, protected from light

Radiolabelling:

no

Test temperature:

20 °C

Details on study design: HPLC method:

Analytical Method

In the course of this study an HPLC analysis of Pen V Potassium in soil matrix was validated. The procedure was found to be suitable for the analysis. The validation parameters meet the acceptance criteria set in the corresponding Study Plan. The summary of the method parameters is presented:
Results of the Method Validation in 0.01M CaCl2 solution
Specificity No interfering component was detected Linear range 0.2 – 50 μg/mL
Limit of Quantification in 0.01M CaCl2 solution0.4 μg/mL
Recovery of Pen V Potassium from 0.01M CaCl2 solution : 102 % (0.02 mg/mL) - 100 % (0.2 mg/mL) 100 % (0.4 mg/mL) - 97 % (0.4 μg/mL)
Precision < 2 %
Stability of the test item in 0.01M CaCl2 solution at the temperature 15-25 °C, 0.02 – 0.2 – 0.4 mg/mL for 7 days 92 – 94 – 95 %
0.02 – 0.2 – 0.4 mg/mL for 14 days % 84 – 87 – 85 %
Stability of Pen V Potassiumin distilled water after 3 days at 5±3 °C temperature 101 % at ca. 200 mg/mL / 99 % at ca. 1 mg/mL
Stability of the calibration samples stable at least 22 hours in the autosampler
Stability of the stock solution stable at least 7days at 5 ± 3 °C

Results of the Method Validation in soil extract

Specificity: No interfering component was detected
Limit of Quantification in soil extract 10 μg/g
Recovery of Pen V Potassium from soil extract
0.5 mg/g: 94 – 102 %
5 mg/g: 95 – 105 %
10 mg/g: 95 – 104 %
0.1 mg/g: 92 – 96 %
Precision≤ 4 %

Analytical monitoring:

not specified

Matrix no.:

#1

Matrix type:

silty clay loam

% Clay:

ca. 27.6

% Silt:

ca. 58.7

% Sand:

ca. 13.7

% Org. carbon:

ca. 1.91

pH:

ca. 6.8

Matrix no.:

#2

Matrix type:

sandy loam

% Clay:

ca. 15.3

% Silt:

ca. 25.5

% Sand:

ca. 59.3

% Org. carbon:

ca. 0.51

pH:

ca. 4.52

Matrix no.:

#3

Matrix type:

silty clay loam

% Clay:

ca. 31.5

% Silt:

ca. 61.9

% Sand:

ca. 6.7

% Org. carbon:

ca. 0.69

pH:

ca. 5.89

Matrix no.:

#4

Matrix type:

silty clay loam

% Clay:

ca. 35.9

% Silt:

ca. 61.7

% Sand:

ca. 2.5

% Org. carbon:

ca. 2.98

pH:

ca. 6.77

Matrix no.:

#5

Matrix type:

loam

% Clay:

ca. 18.1

% Silt:

ca. 32.9

% Sand:

ca. 48.9

% Org. carbon:

ca. 1.21

pH:

ca. 6.96

Details on matrix:

Soils were not treated with fertilizer or organic fertilizer. Herbicide was not used.
Cultivation branch: arable land, grass.
Soils were collected from a maximum depth of 20 cm.
The soil was stored until use under aerobic circumstances in a dark plastic box at the temperature 15-25 °C where the temperature is monitored.
The air-dried soils were sieved to a particle size ≤ 2 mm. The moisture content of each soil was determined with the help of a gravimetric moisture balance.
The soil samples were sterilized for the adsorption-desorption study.
For all the calculations the dry mass of soils was used.

Details on test conditions:

Known volumes of solutions of the test item, at known concentrations in 0.01M CaCl2 are added to soil samples of known dry weight which have been pre-equilibrated in 0.01M CaCl2. Mixtures are agitated for an appropriate time interval. The soil suspensions are then separated, the aqueous and soil phases are analysed and the amount of test item adsorbed on the soil is calculated. All experiments were carried out at laboratory ambient temperature in 50 mL PTFE centrifuge tubes.
After the equilibration period soil and aqueous phases of the test mixtures were separated by centrifugation at 4000 rpm, 20 °C for 10 minutes, the separated phases were filtered (0.45 µm filter) and analysed for Pen V Potassium using the previously validated analytical method.
Samples of aqueous phases were diluted with dilution mixture before analysis or were analysed by HPLC directly. Soil phases were extracted with extraction solution. The extracts were measured separately by HPLC after centrifugation directly or after dilution (dilution mixture).
The pH of the aqueous phase was measured in the control and after the centrifugation in the samples of equilibration.

HPLC Conditions

Detector: 265 nm
Column: PerfectSil 100 ODS-3, 3 µm, 150*4.6 mm No.: 29161703
Mobile phase: Mixture of Acetonitrile and ultra-pure water with
o-phosphoric acid at a ratio of 45:55:0.1 (v/v)
Flow: 1 mL/min
Injection volume: 20 µL
Temperature: 25 °C
Retention time of test item: 5.6 min ± 5 %

The moisture content of each soil was determined on three aliquots with the help of a gravimetric moisture balance. For all the calculations the dry mass of soils was used.

Key result

Sample No.:

#1

Type:

Koc

Value:

ca. 27 dimensionless

pH:

6.8

Temp.:

25 °C

Matrix:

#1 silty clay loam

Key result

Sample No.:

#2

Type:

Koc

Value:

ca. 93 dimensionless

pH:

4.52

Temp.:

25 °C

Matrix:

#2 sandy loam

Key result

Sample No.:

#3

Type:

Koc

Value:

ca. 59 dimensionless

pH:

5.89

Temp.:

25 °C

Matrix:

#3 silty clay loam

Remarks on result:

other:

Key result

Sample No.:

#4

Type:

Koc

Value:

ca. 17 dimensionless

pH:

6.77

Temp.:

25 °C

Matrix:

#4 silty clay loam

Key result

Sample No.:

#5

Type:

Koc

Value:

34 dimensionless

pH:

6.96

Temp.:

25 °C

Matrix:

#5 loam

Adsorption and desorption constants:

see TABLES OF THE EXPERIMENTAL RESULTS attached

Recovery of test material:

see TABLES OF THE EXPERIMENTAL RESULTS attached

Sample no.:

#1

Duration:

6 h

% Adsorption:

ca. 19

Sample no.:

#2

Duration:

6 h

% Adsorption:

ca. 20

Sample no.:

#3

Duration:

6 h

% Adsorption:

ca. 18

Sample no.:

#4

Duration:

6 h

% Adsorption:

ca. 22

Sample no.:

#5

Duration:

6 h

% Adsorption:

ca. 18

Sample no.:

#1

Duration:

6 h

% Desorption:

ca. 80

Sample no.:

#2

Duration:

6 h

% Desorption:

ca. 81

Sample no.:

#3

Duration:

6 h

% Desorption:

ca. 81

Sample no.:

#4

Duration:

6 h

% Desorption:

ca. 80

Sample no.:

#5

Duration:

6 h

% Desorption:

ca. 78

Validity criteria fulfilled:

yes

Conclusions:

The log Koc of Penicillin V Potassium was determined to <1.9.

Executive summary:

Using the Batch Equilibrium Method, the log Koc of Penicillin V Potassium was determined to <1.9.

Description of key information

Using the Batch Equilibrium Method, the log Koc of Penicillin V Potassium was determined to <1.9.

Key value for chemical safety assessment

Koc at 20 °C:

46