2,2'-azobis[2-methylbutyronitrile]

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions) - Method B: Fibre Length and Diameter Distributions

Version / remarks:

The study was conducted according to the test guidelines in effect at the time of study conduct.

Deviations:

no

GLP compliance:

no

Type of method:

electrical sensing zone (e.g. Coulter) method

Type of distribution:

other: electrical sensing zone

Specific details on test material used for the study:

Purity: 99.56%

Percentile:

other: R10

Mean:

21 µm

Remarks on result:

other: see Remark

Remarks:

The R10, R50, and R90 values are Stoke’s radius equivalents of the traditional D10, D50 and D90 values; for 2 μm to 200 μm

Percentile:

other: R50

Mean:

42.2 µm

Remarks on result:

other: see Remark

Remarks:

The R10, R50, and R90 values are Stoke’s radius equivalents of the traditional D10, D50 and D90 values; for 2 μm to 200 μm

Percentile:

other: R90

Mean:

67.5 µm

Remarks on result:

other: see Remark

Remarks:

The R10, R50, and R90 values are Stoke’s radius equivalents of the traditional D10, D50 and D90 values; for 2 μm to 200 μm

Percentile:

other: Mean Rs

Mean:

43.4 µm

Remarks on result:

other: see Remark

Remarks:

mean Stoke’s effective hydrodynamic radius for the material was determined to be 43.4 microns; for 2 μm to 200 μm

The test substance particles were determined to consist of mostly irregular spheroids.

OECD 110 Method A: The Multisizer III, electrosensing zone analysis of three separate preparations indicated an effective single modal distribution of the test material. The samples were analyzed at pH 7.0 using a concentration of approximately 0.02 mg test substance compound to one gram of the saturated solution . The mean particle size diameter averaging the full distribution of three analyses was determined to be 43.5 microns corresponding to approximately 100 percent of the sample. This data is in reasonable agreement with light scattering data which provided a mean radius of 33.2 microns giving a coefficient of variation of 18.9% between the measurements. The mass of particles having a radius below 2 microns was determined by electrosensing zone measurement. A statistically significant value from the mass balance was not achieved. The mean Stoke’s effective hydrodynamic radius for the material was determined to be 43.4 microns assuming equivalence between the electrical sensing zone radius and Stoke’s hydrodynamic radius. The R10, R50, and R90 values are Stoke’s radius equivalents of the traditional D10, D50 and D90 values. That is R10 represents the Rs at which 10% of the material with an Rs between 2 and 200 microns falls below. Similarly, R50 represents the Rs for 50% and R90 the Rs for 90%.

Analysis	Mass Percent for given Rs			Additional Data for 2 μm to 200 μm
	<2 μm	2 μm to 200 μm	>200 μm	Mean Rs	R10	R50	R90
Analysis #1	0.1%	99.9%	0%	44.6	21.6	42.5	71.0
Analysis #2	0.1%	99.9%	0%	41.7	20.9	41.7	66.0
Analysis #3	0.1%	99.9%	0%	42.4	20.5	42.4	65.5
Average	0.1%	99.9%	0%	43.4	21.0	42.2	67.5

Conclusions:

This study and the conclusions which are drawn from it fulfill the quality criteria (validity, reliability, repeatability).

Approximately, 99.9% of the material was found to have a radius between 2 and 200 microns. Mean radius = 43.5 microns.

Executive summary:

The test substance particles were determined to consist of mostly irregular spheroids.

OECD 110 Method A: The electrosensing zone analysis of three separate preparations indicated an effective single modal distribution of the test material. The samples were analyzed at pH 7.0 using a concentration of approximately 0.02 mg test substance compound to one gram of the saturated solution . The mean particle size diameter averaging the full distribution of three analyses was determined to be 43.5 microns corresponding to approximately 100 percent of the sample. This data is in reasonable agreement with light scattering data which provided a mean radius of 33.2 microns giving a coefficient of variation of 18.9% between the measurements. The mass of particles having a radius below 2 microns was determined by electrosensing zone measurement. A statistically significant value from the mass balance was not achieved. The mean Stoke’s effective hydrodynamic radius for the material was determined to be 43.4 microns assuming equivalence between the electrical sensing zone radius and Stoke’s hydrodynamic radius. The R10, R50, and R90 values are Stoke’s radius equivalents of the traditional D10, D50 and D90 values. That is R10 represents the Rs at which 10% of the material with an Rs between 2 and 200 microns falls below. Similarly, R50 represents the Rs for 50% and R90 the Rs for 90%.

Description of key information

~99.9% had a radius between 2 and 200 microns.  Mean radius = 43.5 microns.

Additional information

OECD 110, using electrical sensing zone method