Gadoliniumsulfite trihydrate

Particle size distribution (Granulometry)

Administrative data

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

In a first step, the dispersion agent (ethanol) was added into the system and brought to constant circulation. Then, an underground determination and system calibration was carried out by measuring the particles contained in the dispersion agent. The resulting particle contamination was 0.00 %. Afterwards, some powder of Gd2(SO3)3 • 3 H2O was added into the ethanol at time t0 until an optimum intensity of the scattered light was achieved (Copt = 10.03 %). The first measurment was started at t1 = 4 min 8 s after t0. Recording of particle size data for the first measurement was carried out for 10 s. The measurements were then repeated in the same way at t2 = 19 min 42 s and t3 = 29 min 26 s after t0 without exchanging the suspension in between.
The calculation model used for determination of the particle size distribution assumes each particle to have spherical shape. Thus, the distribution curves calculated by the software of the system display the particle distribution vs. an averaging particle diameter. It is also important to point out that the distribution is volume based and does not refer to the number of particles.

GLP compliance:

not specified

Type of method:

Laser scattering/diffraction

Type of particle tested:

aggregate

Type of distribution:

volumetric distribution

Test material

Test material information

Constituent 1

Reference substance name:

Gadoliniumsulfite trihydrate

EC Number:

456-900-2

EC Name:

Gadoliniumsulfite trihydrate

Cas Number:

51285-81-5

Molecular formula:

Gd2(SO3)3*3H2O

IUPAC Name:

digadolinium(3+) trihydrate trisulfite

Test material form:

solid: particulate/powder

Details on test material:

white dry powder
sample name: 2-02-M

Results and discussion

Mass median aerodynamic diameter:

93.6 µm

Particle size

Particle size 1

Key result

Percentile:

D99

Mean:

178.47 µm

St. dev.:

1.2

Particle size 2

Key result

Percentile:

D90

Mean:

138.32 µm

St. dev.:

1.45

Particle size 3

Key result

Percentile:

D50

Mean:

93.57 µm

St. dev.:

0.83

Particle size 4

Key result

Percentile:

D10

Mean:

52.4 µm

St. dev.:

0.48

Applicant's summary and conclusion

Executive summary:

The measurement was carried out with the laser diffraction spectroscopy device Sympatec Helos KR equipped with three lenses R1, R3, and R5 for particle sizes in the range of 0.1 to 875 µm. The device fully agrees with ISO 13320 (“Particle size analysis - laser diffraction methods”). Data interpretation was carried out with the software WINDOX 5.7.1.0 provided by the equipment manufacturer Sympatec. In a first step, the dispersion agent (ethanol) was added into the system and brought to constant circulation. Then, an underground determination and system calibration was carried out by measuring the particles contained in the dispersion agent. The resulting particle contamination was 0.00 %. Afterwards, some powder of Gd2(SO3)3 • 3 H2O was added into the ethanol at time t0 until an optimum intensity of the scattered light was achieved (Copt = 10.03 %). The first measurment was started at t1 = 4 min 8 s after t0. Recording of particle size data for the first measurement was carried out for 10 s. The measurements were then repeated in the same way at t2 = 19 min 42 s and t3 = 29 min 26 s after t0 without exchanging the suspension in between. The calculation model used for determination of the particle size distribution assumes each particle to have spherical shape. Thus, the distribution curves calculated by the software of the system display the particle distribution vs. an averaging particle diameter. It is also important to point out that the distribution is volume based and does not refer to the number of particles. All measurements were carried out at room temperature (25°C). A density of 4.1 g / cm3 and an aspect ratio of 1.0 was used for particle size calculations.

Results:

•       The powder of gadolinium sulphite trihydrate (Gd2(SO3)3 • 3 H2O) investigated by laser diffraction spectroscopy shows a monomodal particle size distribution.

•       The spherical aggregates have sizes between 10-250 µm with 99 vol. % of the particles having sizes < 180 µm.

•       The MMAD was calculated to 93.6(7) µm.

•       The aggregates consist of platelike crystallites (< 10 µm).

•       No significant volume of particles < 10 µm was detected.

•       The powder particles have a low probability of fragmentation.

•       The findings of the laser diffraction spectroscopy investigation are supported by SEM images of the same substance.