Ibuprofen

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study with analytical monitoring

Data source

Reference

Reference Type:

publication

Title:

Envonrmental fate of pharmaceuticals in water/sediment systems

Author:

Löffler D. et al

Year:

2005

Bibliographic source:

Environ. Sci. Technol. 39, 5209 - 5218

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 308 (Aerobic and Anaerobic Transformation in Aquatic Sediment Systems)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Ibuprofen

EC Number:

239-784-6

EC Name:

Ibuprofen

Cas Number:

15687-27-1

Molecular formula:

C13H18O2

IUPAC Name:

2-(4-isobutylphenyl)propanoic acid

Details on test material:

- Name of test material (as cited in study report): ibuprofen
- Radiochemical purity (if radiolabelling): > 99%
- Specific activity (if radiolabelling): 8.97 MBq/mg
- Locations of the label (if radiolabelling): carboxyl-14C

Radiolabelling:

yes

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

natural water / sediment

Details on source and properties of surface water:

- Details on collection:
- Location: Wickerbach creek in Floersheim, Germany; sampling site is located close to the source of the creek
- Selection criteria: absence of sewage treatment plant discharges
- Storage conditions: combined water and sediment were stored at a ratio of (3:1) at 4 °C in the dark
- Storage length: a maximum of 28 d
- pH at time of collection: 8.5
- Electrical conductivity: 515 µS/cm
- Redox potential (mv): 382
- Oxygen concentration (mg/L) initial/final: 7.8
- Hardness (CaCO3): 222 mg/L
- TOC: 4.7 mg/L

Details on source and properties of sediment:

- Details on collection:
- Location: Wickerbach creek in Floersheim, Germany; sampling site is located close to the source of the creek
- Selection criteria: low but still environmentally relevant organic carbon content; absence of sewage treatment plant discharges
- Sampling depth was restricted to 5 cm, mainly under oxigen conditions
- Storage conditions: combined water and sediment were stored at a ratio of (3:1) at 4 °C in the dark
- Storage length: a maximum of 28 d
- Soil type: loamy sand
- Textural classification
- sand: 77.5%
- silt: 12.6%
- clay): 9.9%
- pH at time of collection: 7.7
- Organic matter (% dw): 2.4
- Redox potential (mv): 269
- Water content: 20

Duration of test (contact time):

100 d

Parameter followed for biodegradation estimation:

radiochem. meas.

test mat. analysis

Details on study design:

TEST CONDITIONS
- Test vessel: 500 ml amber glass flasks, the vessels were wrapped with aluminium foil to minimize photochemical reactions
- Volume of water/sediment: 300 ml creek water and 200 g sediment
- CO2 traps: 30 g of granulated soda lime were sealed tightly to the flasks
- Test temperature: 20 ± 2 °C

PRETREATMENT
- Water/sediment systems were equilibrated under test conditions for at least 7 d. During the equilibration and the study period the test system were shaken slowly.
- Test substance was spiked into the water phase at the beginning of the study period.

SAMPLING
- Sampling frequency: after 0, 0.25, 1, 2, 7, 14, 28, 56, 100 d
- Taken samples: entire water, sediment phase, soda lime of each test system
- Sample storage before analysis: at - 20 °C

Results and discussion

Mean total recovery

Mean total recovery 1

Compartment:

other: water, material (mass) balance

% Recovery:

90

Mean total recovery 2

Compartment:

other: sediment, material (mass) balance

% Recovery:

92

% Degradation

% Degr.:

50

Parameter:

radiochem. meas.

Sampling time:

6 d

Half-life of parent compound / 50% disappearance time (DT50)

Compartment:

entire system

DT50:

< 6 d

Type:

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

Remarks on result:

other: DT90 < 6 d

Transformation products:

not specified