Registration Dossier

Administrative data

Endpoint:
biodegradation in soil
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1993

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
No data
GLP compliance:
no
Test type:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

% Degradation
% Degr.:
> 60
Parameter:
other: DMSO reduction to DMS
Sampling time:
12 wk
Half-life / dissipation time of parent compound
Type:
other: DMS measurement
Transformation products:
yes
Identity of transformation products
No.:
#1
Reference
Reference substance name:
Unnamed
Inventory number:
InventoryMultipleMappingImpl [inventoryEntryValue=EC 200-846-2]
IUPAC name:
dimethyl sulfide
CAS number:
75-18-3
Details on transformation products:
The reduction of DMSO to dimethyl sulfide (DMS) in soil was measured in a range of 47 New Zealands topsoils and humus samples.
The relationships between the rate of DMSO reduction and soil type and land use, organic C and N, the soil microbial C estimated by the substrate-induced-respiration (SIR) method, mineralization of N under anaerobic incubation and the mineralization of organic S, were investigated.

DMSO was reduced rapidly in all soils and rates ranged between 180 and 8124 ng DMS/g soil/h, with the coefficient of variance being typically <10%.

Reduction was significantly correlated with the organic carbon and N content of the 44 mineral soils (r=0.61 and 0.62 respectively), anaerobically mineralized N (r= 0.80), microbial biomass C (r=0.81) and aerobically mineralized SO4-S (r=0.60).

The reduction of DMSO was shown to be more sensitive to the presence of Cr (VI) or As (V) than was the SIR response. The sensitivity and reproducibility of the assay make the technique potentially useful for the study of microbial activity in aggregates, rhizospheres samples and contaminated soils.
Details on results:
Results being expressed as ng DMS/g microbial biomass/hour, it has not been possible to properly calculate back a real percentage of degradation for DMSO. Nevertheless, based on the conclusion of hte Author, the degradation is fast and it is expected to have more than 60% of degradation at the end of the experiment.

Applicant's summary and conclusion