o-TOLUIDINE CAS N°: 95-53-4 - UNEP Chemicals

OECD SIDS o-TOLUIDINE
3. ENVIRONMENTAL FATE AND PATHWAYS ID: 95-53-4
DATE: 07.01.2005
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systems at equivalent cation charge and reflects the formation of an amine
water bridge with the exchangeable Ca2+.
Test condition : - Soil:
Wyoming bentonite (SWy-1) from the Clay Mineral Society Source Clays
Repository
- Preparation of clay:
Calcium-saturated clay suspensions were generated by repeated
centrifuge washing with 0.5 M Ca(C2H3O2)2 at pH 4. After 3 washings the
clay was washed twice with type I deionized water and three times with
either 0.01 M CaCl2, 0.1 M CaCl2 or 0.005 M CaSO4. The suspensions
contained between 9.99 and 10.04 mg/ml of clay over the course of the
study. The K+-saturated SWy-1 bentonite was prepared in a similar
manner to that described above.
- Preliminary test:
An adequate completion time of adsorption reaction found out was 4 hours.
The adsorption equilibrium was stable up to 48 hours and no adsorption on
the Corex centrifuge tubes occurred
- Stock solution:
2000 mg/l (containing 21.48 mmol/l aniline and 18.67 mmol/l o-toluidine)
prepared in the appropriate Ca2+ or K+ background electrolyte solution
- test vessel:
50 ml centrifuge tubes sealed with Teflon-lined screw caps, wrapped in
aluminum foil.
- Temperature:
20 - 25 °C
- Test method:
20 ml of clay suspension, 20 ml of aniline or toluidine solution and 5 ml of a
pH-adjusting solution were placed in centrifuge tubes sealed with screw
caps (The final clay concentration was 4.44 mg/ml). pH-adjusting solutions
were composed of the background electrolyte and 0.2 M HCl or H2SO4
that ranged in composition from 100 % background electrolyte to a 1:1
mixture. Equilibration was performed on a wrist-action shaker for 24 hours.
The adsorption system was centrifuged at 1,140 x g (maximum radius).
- Replicate:
The experiments including blanks were run in triplicate
- Analysis:
10 ml aliquot was extracted and placed in a 100 ml volumetric flask. A 10
ml aliquot of 0.1 M Ca(OH)2 or KOH was added. Analysis was performed
by UV spectrophotometry (Shimadzu UV-265 spectrophotometer) at
wavelength of approx. 280 nm.
- pH determination:
The pH-value of the equilibrium supernatant solution was determined using
a standardized (pH 4 and 7) combination pH electrode and a Sargent-
Welch MPT automatic titrator microprocessor. Standard solutions for UV
analysis ranged in concentration from 10-20 mg/l.
Test substance : o-Toluidine, purity 99 %, supplied by Aldrich Chemical Co. (Milwaukee,
WI). The substance was used without further purification.
Reliability : (2) valid with restrictions
Comparable to guideline study with acceptable restrictions
Flag : Critical study for SIDS endpoint
20.06.2004 (39) (40)
3.4 MODE OF DEGRADATION IN ACTUAL USE
3.5 BIODEGRADATION
Type : aerobic
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