alkoxy substituted aryl diazo heterocyclic aryl nitrile

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

November 12, 2014

Reliability:

other: This study is fully reliable (1) for the milled press cake produced for testing purposes, but not relevant for the imported or marketed dye product, which has a markedly larger particle size due to preparation with dedusting agents and/or spray drying.

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD 110) - tested from milled press cake to support the data of the physico-chemical and (eco)toxicological data collection

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions)

Principles of method if other than guideline:

Laser Diffraction: The particle size distribution of the test item is determined by laser diffraction (light scattering).
The light from a low power Helium-Neon laser is used to form a collimated and monochromatic beam of light, typically 1 cm in diameter. The beam of light is known as the analyser beam and any particles present within this beam will scatter this laser light. The light scattered by the particles and the unscattered remainder falls onto a receiver lens. This lens operates as a fourier transform lens forming the far field diffraction pattern of the scattered light at its focal plane. Here a detector, in the form of a series of 36 elements gathers the scattered light energy over a range of fixed angles of scatter.
The unscattered light is brought to a focus on the detector and passed through a small aperture in the detector and out of the optical system. The total laser power passing out of the system in this way is monitored as it allows the sample volume concentration to be determined. Due to the receiver lens configuration the diffraction pattern of the particle was stationary and centred on the optical axis of the receiver lens wherever the particle is in the analyser beam. It does also not matter that the particle is moving through the analyser beam, the diffraction pattern remains stationary and centred on the axis. Normally many particles are simultaneously present in the analyser beam and the scattered light measured on the detector is the sum of all individual patterns overlaid on the central axis. The scattering angle of a particle is related to the diameter of the particle. Large particles scatter light into small angles of scatter; this means the diffraction pattern will be found on the inner concentric rings of the detector. Small particles on the other side scatter light into large angles of scatter; this means the diffraction pattern will be found on the outer concentric rings of the detector. From the light energy measured by the 36 elements on the detector the computer calculates the volume based particle size distribution. If the test item consists of a homogeneous material, with a constant density, the volume based distribution equals to the mass based distribution.

GLP compliance:

yes (incl. QA statement)

Type of distribution:

volumetric distribution

Percentile:

D50

Mean:

14.1 µm

St. dev.:

0.05

Percentile:

D10

Mean:

3.9 µm

St. dev.:

0

Percentile:

D90

Mean:

44.8 µm

St. dev.:

1.3

Results of Laser Diffraction

The test item consisted of small particles which partially tended to agglomeration.

The particles were introduced to the analyser beam by the dry powder feeder by direct spraying through the measurement area. The powder was loosened by an integrated vibrator. The particles were dispersed and fed to the optical system by pressurized dry air (1.5 bar_g). After passing the spectrometer the sample was collected in a vacuum cleaner.

After adjusting the laser, measuring the background and adjusting the correct particle concentration (obscuration) the measurement was started. The control software automatically performed three measurements. The average of these three measurements was given as result. Two test series of three measurements each were performed. The measurement time was 8 s.

The median particle size L₅₀(D (v, 0.5): 50 % of particle volume or particle mass with lower particle diameter) deduced from these distributions were:

1^st test series:           L₅₀ = 14.1 µm

2^nd test series:          L₅₀ = 14.0 µm

The average of the median particle size L₅₀was:

L₅₀ = 14.1 µm

The particle size L₁₀ (D (v, 0.1): 10 % of particle volume or particle mass with lower particle diameter) deduced from these distributions were:

1^st test series:           L₁₀ = 3.9 µm

2^nd test series:          L₁₀ = 3.9 µm

The average of the particle size L₁₀was:

L₁₀ = 3.9 µm

The particle size L₉₀ (D (v, 0.9): 90 % of particle volume or particle mass with lower particle diameter) deduced from these distributions were:

1^st test series: L₉₀ = 43.6 µm

2^nd test series:           L₉₀ = 46.1 µm

The average of the particle size L₉₀was:

L₉₀ = 44.8 µm

The particle size distribution showed a broad distribution with two maxima at approximately 15 µm and approximately 300 µm. Additionally a shoulder was observed at approximately 1 µm.

Executive summary:

The median particle size L₅₀ of the test item deduced from the particle size distributions was 14.1 µm.

The particle size L₁₀ of the test item deduced from the particle size distributions was 3.9 µm.

The particle size L₉₀ of the test item deduced from the particle size distributions was 44.8 µm.

Reference 2

Endpoint:

particle size distribution (granulometry)

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is marketed or used in a non solid or granular form

Percentile:

D50

Remarks on result:

other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.

Description of key information

The mean particle size of the milled test item (milled press cake for testing purposes) was determined to be 14.1 µm with a 90% range of 3.9 to 44.8 µm; whereas the mean particle size of the imported and marketed product is determined to be 150.8 µm with a 90% range of 56.35 to 245 µm.

Additional information

The particle size of the dedusted dye product of Disperse Blue CVG, which is part of the dye product of the test item as imported and marketed, was determined at its production site by laser diffraction (light scattering).

The median particle size L₅₀ (D (v, 0.5): 50 % of particle volume or particle mass with lower particle diameter) deduced from these distributions are: L₅₀ = 150.8 µm

The particle size L₁₀ (D (v, 0.1): 10 % of particle volume or particle mass with lower particle diameter) deduced from these distributions are: L₁₀= 56.35 µm

The particle size L₉₀ (D (v, 0.9): 90 % of particle volume or particle mass with lower particle diameter) deduced from these distributions are: L₉₀= 245 µm

The particle size distribution of the test item that was milled for testing purposes was determined by laser diffraction (light scattering).

The median particle size L50 of the test item deduced from the particle size distributions was 14.1 µm.

The particle size L10 of the test item deduced from the particle size distributions was 3.9 µm.

The particle size L90 of the test item deduced from the particle size distributions was 44.8 µm.