Hydroquinone

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

Study period:

February-March 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

no guideline followed

Principles of method if other than guideline:

Particle size determination was performed using a laser diffraction apparatus. Particle size analysis by laser diffraction determines the equivalent diameter of a sphere which would have the same volume as the particle. This method does not take into account the shape factor of the particles. Characterization was done using a quartz 50 mL cell requiring some milligrams of solid. Dispersing medium was silicon oil with low viscosity where hydroquinone is not soluble.

GLP compliance:

no

Type of method:

Laser scattering/diffraction

Type of distribution:

volumetric distribution

Percentile:

D50

Mean:

281 - 286 µm

Remarks on result:

other: hydroquinone extra pure: X50=281 µm; hydroquinone premium: X50=286 µm

Percentile:

D10

Mean:

136.4 µm

Remarks on result:

other: hydroquinone extra pure

Percentile:

D90

Mean:

478.8 µm

Remarks on result:

other: hydroquinone extra pure

Percentile:

D10

Mean:

125.8 µm

Remarks on result:

other: hydroquinone premium

Percentile:

D90

Mean:

481.8 µm

Remarks on result:

other: hydroquinone premium

Conclusions:

The particle size distribution of extra pure and premium hydroquinone was determined via laser diffraction. The X10, X50, and X90 values were determined to be 136.4, 286.0, and 478.8 µm for the extra pure quality and 125.8, 281.0, and 481.8 µm for the premium quality, respectively. The amount of fines <100 µm were found to be 4 (extra pure) and 5% w/w (premium) and the classes of particles < 105 µm were determied to be 4.4 (extra pure) and 5.95% in volume (premium).

Executive summary:

The particle size distribution of extra pure and premium hydroquinone was determined via laser diffraction. The X10, X50, and X90 values were determined to be 136.4, 286.0, and 478.8 µm for the extra pure quality and 125.8, 281.0, and 481.8 µm for the premium quality, respectively. The amount of fines <100 µm were found to be 4 (extra pure) and 5% w/w (premium) and the classes of particles < 105 µm were determied to be 4.4 (extra pure) and 5.95% in volume (premium).

Description of key information

extra pure hydroquinone
X10=136.4 µm, X50=286 µm, and X90=478.8 µm; fines<100 µm=4% w/W; classes of particles < 105 µm=4.4% in volume
premium hydroquinone
X10=125.8 µm, X50=281 µm, and X90=481.8 µm; fines<100 µm=5% w/W; classes of particles < 105 µm=5.95% in volume

Additional information

Reliable results are available obtained in study conducted according to a generally accepted method