Phenethyl propionate

Biodegradation in soil

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal and review article.

Justification for type of information:

Data is from peer reviewed journal and review article.

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

Biodegradation study was conducted for 30 days for evaluating the percentage biodegradability of test substance 2-phenylethyl propanoate.

GLP compliance:

not specified

Test type:

laboratory

Specific details on test material used for the study:

- Name of test material (IUPAC name): 2-phenylethyl propanoate
- Common name: Phenethyl propionate (PEP)
- Molecular formula: C11H14O2
- Molecular weight: 178.2296 g/mol
- Smiles notation: c1(CCOC(=O)CC)ccccc1
- InChl: 1S/C11H14O2/c1-2-11(12)13-9-8-10-6-4-3-5-7-10/h3-7H,2,8-9H2,1H3
- Substance type: Organic
- Physical state: Liquid

Radiolabelling:

yes

Oxygen conditions:

aerobic

Soil classification:

other: Laboratory Soil

Soil no.:

#1

Soil type:

sandy loam

% Clay:

18

% Silt:

22

% Sand:

60

% Org. C:

1.6

pH:

7

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location: Soil was collected at the Iowa State University Agronomy and Agricultural Engineering Research Farm near Ames, Iowa [Field 55].

PROPERTIES OF THE SOILS (in addition to defined fields)
- Moisture at 1/3 atm (%): soil moisture content was adjusted to 75% of 1/3 bar moisture.

Soil No.:

#1

Duration:

30 d

Initial conc.:

10 other: μg/g

Based on:

test mat.

Parameter followed for biodegradation estimation:

test mat. analysis

Soil No.:

#1

Temp.:

25 ± 2°C

Humidity:

soil moisture content was adjusted to 75% of -33 J/kg (1/3 bar) moisture

Details on experimental conditions:

- Soil condition: air dried/fresh
- No. of replication treatments: There were four replications for each group.
- Test apparatus (Type/material/volume): 250-ml French square bottle was used as a test vessel. The soil was classified as a sandy loam, a Nicollet-Webster complex with 1.6% organic matter, 60% sand, 22% silt, 18% clay, and pH 7.0. Soil (50g) was kept in a 250-ml French square bottle.
- Details of traps for CO2 and organic volatile, if any: Polyurethane foam was suspended above the treated soils inside each bottle to capture volatile compounds. 1.5g of Drierite® (anhydrous calcium sulfate) was used to trap tritium H2O in the air in the container. Drierite was changed when it turned pink.

Soil No.:

#1

% Recovery:

90

Remarks on result:

other: More than 90% as determined spike-recovery experiments at the initial time point.Volatility loss was negligible in one month with mass balance from 96% to 100%.

Key result

Soil No.:

#1

DT50:

4 d

Type:

(pseudo-)first order (= half-life)

Temp.:

25 °C

Remarks on result:

other: Other details not known

Transformation products:

yes

Remarks:

2-Phenylethanol and 2-(4-hydroxyphenyl) ethanol were found as the degradation of 2-phenylethyl propanoate.

No.:

#1

No.:

#2

Details on transformation products:

Formation and decline of each transformation product during test: 2-Phenylethanol reached the maximal concentration in 1 week both in water and in soil; however, the peak in soil was 36% of total radioactivity compared to 74% of total radioactivity in water. The formation of 2-(4-hydroxyphenyl) ethanol was also less in soil than in water.
Description of biotransformation pathway: Another degradation product was 2-(4-hydroxyphenyl) ethanol, which was probably a biotransformation product of 2-phenylethanol in microbes. This is evidenced by coincidence of increase of the latter and decrease of the former while the overall mass balance remained constant.

Evaporation of parent compound:

no

Volatile metabolites:

no

Residues:

no

Details on results:

TEST CONDITIONS
- Aerobicity, moisture, temperature and other experimental conditions maintained throughout the study: Yes

MINERALISATION
% of applied radioactivity present as CO2 at end of study: Mineralization was less than 3%.

VOLATILIZATION
% of the applied radioactivity present as volatile organics at end of study: Average radioactivity as bound residues remained below 6%.

The retention time for test substance PEP was 5.4 min on the HPLC chromatogram.

 

Table: Dissipation half-lives (DT50) of PEP in soil.

 

Incubation conditions	DT50 (days) (± S. D.)	R^2a	Replication (n)
PEP in soil	3.92 (±0.19)	0.84	4

 

Where,

a = R²is the correlation coefficient for the first order dissipation model.

Conclusions:

The half-life of test substance 2-phenylethyl propanoate was determined to be 4 days. The degradation product of chemical 2-phenylethyl propanoate were 2-Phenylethanol and 2-(4-hydroxyphenyl) ethanol, respectively.

Executive summary:

Biodegradation study was conducted for 30 days for evaluating the percentage biodegradability of test substance 2-phenylethyl propanoate. 3H-phenethyl propionate were purchased from PerkinElmer Life Sciences and Analytical Sciences. (Boston, MA, USA). Analytical standards of phenethyl propionate, 2-phenylethanol, 2-(4-hydroxyphenyl) ethanol were purchased from Lancaster Synthesis, Inc. Methanol was purchased from Fisher Scientific Solvents used for extraction and chromatographic analysis were analytical reagent grade or better. Monophase® S scintillation cocktails were purchased from PerkinElmer Life and Analytical Sciences.Initial test substance conc. used for the study was 10μg/g. Soil was collected at the Iowa State University Agronomy and Agricultural Engineering Research Farm near Ames, Iowa [Field 55].The soil contained 1.6% organic matter, 60% sand, 22% silt, 18% clay, and pH 7.0. Soil (50g) was kept in a 250-ml French square bottle, and soil moisture content was adjusted to 75% of 1/3 bar moisture.The temperature was maintained at 25 ± 2°C. Soil samples were treated with 3HPEP in methanol at 10 μg/g. Bottles were sealed with Teflon® caps. Polyurethane foam was suspended above the treated soils inside each bottle to capture volatile compounds. Polyurethane foam was changed biweekly. 1.5g of Drierite® (anhydrous calcium sulfate) was used to trap tritium H2O in the air in the container. Drierite was changed when it turned pink. Soil sampling times were at pre-treatment, at 1, 3, 7, 14, and 30 days post-treatment.

Quantitative analysis of PEP was performed using a Hewlett-Packard (Palo Alto, CA, USA) series 1100 HPLC system with a quaternary pump, an autosampler, a thermostatted column compartment, and a Spectroflow 757 absorbance detector (ABI Analytical, Kratos Division, Ramsey, NJ, USA). Data were collected and analyzed using HP Chemstation system software (REV. A.04.01). An Alltech Adsorbosphere® (Deerfield, IL, USA) C18 column (4.6×250 mm, 5-μm particle size) was used. Detection was conducted at 270 nm with a flow rate of 1.0 ml/min at room temperature. The mobile phase was methanol/distilled water (70:30, v/v). Soil samples (50 g) were extracted with methanol/distilled water (95:5) three times, and the resulting extracts were pooled. Filtered samples were directly injected for HPLC analysis. HPLC fractions were collected for liquid scintillation counting (LSC). Drierite and polyurethane foam were thoroughly extracted with methanol, and the resulting extracts were subjected to LSC to measure trapped radioactivity. Non-extractable radioactive residues in soil were measured by soil combustion using a Packard sample oxidizer. A 0.5-g soil sample was incorporated into a cellulose pellet, and three replications were performed for each treatment.Dissipation rates of PEP were calculated using first-order open models. A student’st-test was used to compare dissipation rates of PEP in light and in dark from the water dissipation studies.The half-life of test substance2-phenylethyl propanoatewas determined to be4 days.The degradation product of chemical 2-phenylethyl propanoate were 2-Phenylethanol and 2-(4-hydroxyphenyl) ethanol, respectively. 2-Phenylethanol reached the maximal concentration in 1 week both in water and in soil; however, the peak in soil was 36% of total radioactivity compared to 74% of total radioactivity in water. The formation of 2-(4-hydroxyphenyl) ethanol was also less in soil than in water.The average radioactivity as bound residues remained below 6%, and mineralization was less than 3%.Based on this half-life value of test chemical 2-phenylethyl propanoate (i.e 4 days), it is concluded that the chemical 2-phenylethyl propanoate is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Description of key information

Biodegradation study was conducted for 30 days for evaluating the percentage biodegradability of test substance 2-phenylethyl propanoate (Dingfue Hu and Joel Coats, 2008 & Dingfue Hu, 2007). 3H-phenethyl propionate were purchased from PerkinElmer Life Sciences and Analytical Sciences. (Boston, MA, USA). Analytical standards of phenethyl propionate, 2-phenylethanol, 2-(4-hydroxyphenyl) ethanol were purchased from Lancaster Synthesis, Inc. Methanol was purchased from Fisher Scientific Solvents used for extraction and chromatographic analysis were analytical reagent grade or better. Monophase® S scintillation cocktails were purchased from PerkinElmer Life and Analytical Sciences.Initial test substance conc. used for the study was 10μg/g. Soil was collected at the Iowa State University Agronomy and Agricultural Engineering Research Farm near Ames, Iowa [Field 55].The soil contained 1.6% organic matter, 60% sand, 22% silt, 18% clay, and pH 7.0. Soil (50g) was kept in a 250-ml French square bottle, and soil moisture content was adjusted to 75% of 1/3 bar moisture.The temperature was maintained at 25 ± 2°C. Soil samples were treated with 3HPEP in methanol at 10 μg/g. Bottles were sealed with Teflon® caps. Polyurethane foam was suspended above the treated soils inside each bottle to capture volatile compounds. Polyurethane foam was changed biweekly. 1.5g of Drierite® (anhydrous calcium sulfate) was used to trap tritium H2O in the air in the container. Drierite was changed when it turned pink. Soil sampling times were at pre-treatment, at 1, 3, 7, 14, and 30 days post-treatment.

Quantitative analysis of PEP was performed using a Hewlett-Packard (Palo Alto, CA, USA) series 1100 HPLC system with a quaternary pump, an autosampler, a thermostatted column compartment, and a Spectroflow 757 absorbance detector (ABI Analytical, Kratos Division, Ramsey, NJ, USA). Data were collected and analyzed using HP Chemstation system software (REV. A.04.01). An Alltech Adsorbosphere® (Deerfield, IL, USA) C18 column (4.6×250 mm, 5-μm particle size) was used. Detection was conducted at 270 nm with a flow rate of 1.0 ml/min at room temperature. The mobile phase was methanol/distilled water (70:30, v/v). Soil samples (50 g) were extracted with methanol/distilled water (95:5) three times, and the resulting extracts were pooled. Filtered samples were directly injected for HPLC analysis. HPLC fractions were collected for liquid scintillation counting (LSC). Drierite and polyurethane foam were thoroughly extracted with methanol, and the resulting extracts were subjected to LSC to measure trapped radioactivity. Non-extractable radioactive residues in soil were measured by soil combustion using a Packard sample oxidizer. A 0.5-g soil sample was incorporated into a cellulose pellet, and three replications were performed for each treatment.Dissipation rates of PEP were calculated using first-order open models. A student’st-test was used to compare dissipation rates of PEP in light and in dark from the water dissipation studies.The half-life of test substance2-phenylethyl propanoate was determined to be4 days.The degradation product of chemical 2-phenylethyl propanoate were 2-Phenylethanol and 2-(4-hydroxyphenyl) ethanol, respectively. 2-Phenylethanol reached the maximal concentration in 1 week both in water and in soil; however, the peak in soil was 36% of total radioactivity compared to 74% of total radioactivity in water. The formation of 2-(4-hydroxyphenyl) ethanol was also less in soil than in water.The average radioactivity as bound residues remained below 6%, and mineralization was less than 3%.Based on this half-life value of test chemical 2-phenylethyl propanoate (i.e 4 days), it is concluded that the chemical 2-phenylethyl propanoate is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Key value for chemical safety assessment

Half-life in soil:

4 d

at the temperature of:

25 °C

Additional information

Biodegradation study was conducted for 30 days for evaluating the percentage biodegradability of test substance 2-phenylethyl propanoate (Dingfue Hu and Joel Coats, 2008 & Dingfue Hu, 2007). 3H-phenethyl propionate were purchased from PerkinElmer Life Sciences and Analytical Sciences. (Boston, MA, USA). Analytical standards of phenethyl propionate, 2-phenylethanol, 2-(4-hydroxyphenyl) ethanol were purchased from Lancaster Synthesis, Inc. Methanol was purchased from Fisher Scientific Solvents used for extraction and chromatographic analysis were analytical reagent grade or better. Monophase® S scintillation cocktails were purchased from PerkinElmer Life and Analytical Sciences.Initial test substance conc. used for the study was 10μg/g. Soil was collected at the Iowa State University Agronomy and Agricultural Engineering Research Farm near Ames, Iowa [Field 55].The soil contained 1.6% organic matter, 60% sand, 22% silt, 18% clay, and pH 7.0. Soil (50g) was kept in a 250-ml French square bottle, and soil moisture content was adjusted to 75% of 1/3 bar moisture.The temperature was maintained at 25 ± 2°C. Soil samples were treated with 3HPEP in methanol at 10 μg/g. Bottles were sealed with Teflon® caps. Polyurethane foam was suspended above the treated soils inside each bottle to capture volatile compounds. Polyurethane foam was changed biweekly. 1.5g of Drierite® (anhydrous calcium sulfate) was used to trap tritium H2O in the air in the container. Drierite was changed when it turned pink. Soil sampling times were at pre-treatment, at 1, 3, 7, 14, and 30 days post-treatment.

Quantitative analysis of PEP was performed using a Hewlett-Packard (Palo Alto, CA, USA) series 1100 HPLC system with a quaternary pump, an autosampler, a thermostatted column compartment, and a Spectroflow 757 absorbance detector (ABI Analytical, Kratos Division, Ramsey, NJ, USA). Data were collected and analyzed using HP Chemstation system software (REV. A.04.01). An Alltech Adsorbosphere® (Deerfield, IL, USA) C18 column (4.6×250 mm, 5-μm particle size) was used. Detection was conducted at 270 nm with a flow rate of 1.0 ml/min at room temperature. The mobile phase was methanol/distilled water (70:30, v/v). Soil samples (50 g) were extracted with methanol/distilled water (95:5) three times, and the resulting extracts were pooled. Filtered samples were directly injected for HPLC analysis. HPLC fractions were collected for liquid scintillation counting (LSC). Drierite and polyurethane foam were thoroughly extracted with methanol, and the resulting extracts were subjected to LSC to measure trapped radioactivity. Non-extractable radioactive residues in soil were measured by soil combustion using a Packard sample oxidizer. A 0.5-g soil sample was incorporated into a cellulose pellet, and three replications were performed for each treatment.Dissipation rates of PEP were calculated using first-order open models. A student’st-test was used to compare dissipation rates of PEP in light and in dark from the water dissipation studies.The half-life of test substance2-phenylethyl propanoate was determined to be4 days.The degradation product of chemical 2-phenylethyl propanoate were 2-Phenylethanol and 2-(4-hydroxyphenyl) ethanol, respectively. 2-Phenylethanol reached the maximal concentration in 1 week both in water and in soil; however, the peak in soil was 36% of total radioactivity compared to 74% of total radioactivity in water. The formation of 2-(4-hydroxyphenyl) ethanol was also less in soil than in water.The average radioactivity as bound residues remained below 6%, and mineralization was less than 3%.Based on this half-life value of test chemical 2-phenylethyl propanoate (i.e 4 days), it is concluded that the chemical 2-phenylethyl propanoate is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.