Registration Dossier

Administrative data

Endpoint:
monitoring data
Remarks:
Determination of residue levels in soil
Type of information:
experimental study
Adequacy of study:
key study
Study period:
approx. 25 October - 15 November 1993
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The purpose of the study was:

1). To generate soil samples for residue analysis following treatment with GESATOP 50WP
2). To determine the residue levels of simazine in the soil samples.
3). To compare the results obtained from sampling using two different tube diameters (22.5 mm and 44 mm).
4). To compare the results obtained from 4 adjacent sub-plots.
GLP compliance:
yes (incl. certificate)
Type of measurement:
other: Determination of residue levels in soil
Media:
soil

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Test material: GESATOP 50WP
- Appearance: White to beige powder
- Active ingredient (a.i.): Simazine
- Nominal rate: 500 g a.i./kg
- Actual rate: 47.5 - 52.5% w/w
- Formulation type: WP
- Batch No.of test material: 2296 DA

Study design

Details on sampling:
For the untreated samples, soil cores were taken from 5 randomly distributed points within the untreated plot. The sampling points within the treated plot were within a 12.5 cm radius of the sampling point for each core taken.

Sample 1 (S1): Diluent sample taken immediately prior to T1 application
Sample 2 (S2): Spray deposition samples taken during T1 application
Sample 3 (S3): Soil cores taken 1 - 4 hours after T1 application

Results and discussion

Details on results:
The corrected results compare to the actual rates of recovery from each sample with the anticipated level, based on the surface area of each core. The results were corrected to take account of the procedural recovery rate and the diameters of the cutting edge of the soil core sleeves (21.0 mm and 42.5 mm, respectively). The results are presented in groups of 5 cores and the sub-plot means for each core are provided.

Any other information on results incl. tables

Table 1: Recovery rates of Simazine

Repetition number

Corrected recovery rate (%)

22.5 mm cores

44 mm cores

1

57.1

154.1

2

71.4

64.2

3

22.8

77.4

4

11.4

104.6

5

14.3

61.4

Sub-plot mean

36.4

92.3

6

71.4

106.7

7

88.5

82.3

8

22.8

92.0

9

68.5

83.0

10

71.4

174.3

Sub-plot mean

64.5

107.7

11

37.1

123.4

12

42.8

76.0

13

57.1

61.4

14

60.0

92.7

15

57.1

86.5

Sub-plot mean

50.8

88.0

16

100.0

171.5

17

97.1

131.1

18

74.3

95.5

19

74.3

95.5

20

88.5

97.6

Sub-plot mean

86.8

124.1

OVERALL MEAN

59.4

103.0

Applicant's summary and conclusion

Conclusions:
The results show that the 44 mm diameter cores gave a more accurate measurement of the true dose of pesticide applied to the soil than the 22.5 mm diameter cores. The most probable explanation is that there was a disproportionate disruption of the soil surface as the probe entered the soil, resulting in a smaller area of soil surface entering the tube than would be predicted from the real diameter of the tube.