(R)-quinuclidin-3-ol

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Version / remarks:

1992

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(R)-quinuclidin-3-ol

EC Number:

246-857-6

EC Name:

(R)-quinuclidin-3-ol

Cas Number:

25333-42-0

Molecular formula:

C7H13NO

IUPAC Name:

quinuclidin-3-ol

Test material form:

solid: crystalline

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Source: The source of test organisms was activated sludge freshly obtained from a municipal sewage treatment plant: 'Waterschap Aa en Maas', 's-Hertogenbosch, The Netherlands, receiving predominantly domestic sewage.
Treatment: The freshly obtained sludge was kept under continuous aeration until further treatment. The concentration of suspended solids was determined to be 3.2 g/L in the concentrated sludge. Before use, the sludge was allowed to settle (35 minutes) and the supernatant liquid was used as inoculum at the amount of 10 mL/L of mineral medium.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

18 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

12 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium:
Stock solutions of
A) 8.50 g KH2PO4 mineral components 21.75 g K2HPO4, 67.20 g Na2HPO4.12H2O, 0.50 g NH4Cl, dissolved in Milli-RO water and made up to 1 litre, pH 7.4 ± 0.2
B) 22.50 g MgSO4.7H2O dissolved in Milli-RO water and made up to 1 litre.
C) 36.40 g CaCl2.2H2O dissolved in Milli-RO water and made up to 1 litre.
D) 0.25 g FeCl3.6H2O dissolved in Milli-RO water and made up to 1 litre.
Mineral medium: 1 litre mineral medium contains: 10 mL of solution (A), 1 mL of solutions (B) to (D) and Milli-RO water.

- Test temperature: 22.2 - 23.2°C
- pH: 7.6
- pH adjusted: yes (Adjusted using 1 M HCl (Merck, Darmstadt, Germany)) at start of test
- Aeration of dilution water: yes
- Continuous darkness: yes

TEST SYSTEM
- Number of culture flasks/concentration: 2 bottles (2 Litre coloured glass bottles)
- Method used to create aerobic conditions: Synthetic air (CO2 < 1 ppm) A mixture of oxygen (ca. 20%) and nitrogen (ca. 80%) was passed through a bottle, containing 0.5 - 1 litre 0.0125 M Ba(OH)2 solution to trap CO2 which might be present in small amounts. The synthetic air was passed through the scrubbing solutions at a rate of approximately 1-2 bubbles per second (ca. 30-100 mL/min).
- Test performed in open system: No

SAMPLING
At the start of the test (day 0), test and reference item were added to the bottles containing the microbial organisms and mineral components.The volumes of suspensions were made up to 2 litres with Milli-RO water, resulting in the mineral medium described before. Three CO2-absorbers (bottles filled with 100 mL 0.0125 M Ba(OH)2) were connected in series to the exit air line of each test bottle.
Experimental CO2 production
The CO2 produced in each test bottle reacted with the barium hydroxide in the gas scrubbing bottle and precipitated out as barium carbonate. The amount of CO2 produced was determined by titrating the remaining Ba(OH)2 with 0.05 M standardized HCl (1:20 dilution from 1 M HCl (Titrisol® ampoule), Merck, Darmstadt, Germany).
Measurements
Titrations were made every second or third day during the first 10 days, and thereafter at least every fifth day until day 28, for the inoculum blank and test item. Titrations for the positive and toxicity control were made over a period of at least 14 days.
Each time the CO2-absorber nearest to the test bottle was removed for titration; each of the remaining two absorbers were moved one position in the direction of the test bottle. A new CO2-absorber was placed at the far end of the series. Phenolphthalein (1% solution in ethanol, Merck) was used as pH-indicator.
On the penultimate day, the pH of respective test suspensions was measured and 1 mL of concentrated HCl (37%, Merck) was added to the bottles of the inoculum blank and test suspension. The bottles were aerated overnight to drive off CO2 present in the test suspension. The final titration was made on day 15 (positive and toxicity control) and on day 29 (remaining vessels).

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 2 bottles
- Abiotic sterile control: no
- Toxicity control: yes, 1 bottle
- Positive control: yes , 1 bottle

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

Test performance:

Acceptability of the Test
1. The positive control item was biodegraded by at least 60% (80%) within 14 days.
2. The difference of duplicate values for %-degradation of the test item was always less than 20 (≤ 2%).
3. The total CO2 release in the blank at the end of the test did not exceed 40 mg/L (45.8 mg CO2 per 2 litres of medium, corresponding to 22.9 mg CO2/L).
4. The Inorganic Carbon content (IC) of the test item (suspension) in the mineral medium at the beginning of the test was less than 5% of the Total Carbon content (TC). Since the test medium was prepared in tap-water purified by reverse osmosis (Milli-RO water (Millipore Corp., Bedford, Mass., USA, carbon levels < 500 ppb)), IC was less than 5% of TC (mainly coming from the test item, 12 mg TOC/L).

Since all criteria for acceptability of the test were met, this study was considered to be valid.

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

ca. 7

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

80% degradation after 14 days

Any other information on results incl. tables

Table 1   
Comparison of Biodegradation of the Test Item in Bottles A and B

Day	Biodegradation (%)
	Bottle A	Bottle B	Mean A and B	∆ A-B^1)
1	2	0	1	2
4	2	0	1	2
6	2	1	2	1
8	3	2	3	1
11	3	2	3	1
15	4	2	3	2
18	5	3	4	2
22	5	4	5	1
25	5	4	5	1
29^2)	6	5	6	1
29^2)	7	6	7	1
29^2)	7	6	7	1
^1): Absolute difference in biodegradation between bottles A and B ^2): Biodegradation is ended on day 28 by addition of HCl. Therefore, differences observed on day 29 are actually differences of day 28.

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The tes item was not readily biodegradable under the conditions of the modified Sturm test presently performed.