Inert Particle Experiment Service

Inert Particle Experiment and Characterisation Service – Analysing Particulate Behaviour and Physical Properties for Brazilian Industrial Applications

As an ISO/IEC 17025 accredited independent testing laboratory, we offer specialised inert particle experiment and characterisation services to Brazilian manufacturers, R&D teams, and quality assurance professionals across pharmaceutical, chemical, food, environmental, and advanced materials sectors. Inert particles – defined as non‑reactive, stable solid particulates – are widely used as model tracers, flow aids, catalyst supports, filler materials, and calibration standards. Understanding their physical, chemical, and aerodynamic behaviour is essential for process optimisation, product formulation, quality control, and regulatory compliance. Our experimental platform quantifies key parameters including particle size distribution, density, surface area, porosity, flowability, electrostatic properties, and chemical inertness under controlled conditions. All methods are aligned with ABNT NBR standards, ISO 13322 (Particle size analysis – Image analysis methods), ASTM B822 (Particle size distribution of metal powders), ISO 9277 (BET specific surface area), ASTM D6393 (Bulk solids – Angle of repose), and USP <786> (Particle size distribution estimation by analytical sieving). Our reports are recognised by ANVISA (pharmaceutical and food safety), INMETRO (metrology and certification), IBAMA (environmental compliance), and Brazilian chemical and material companies for product development, supplier qualification, and process validation.

Types of Inert Particles and Sample Matrices We Regularly Test

Our laboratory accommodates a broad range of particulate materials, from fine powders to coarse granules. Typical test samples include:

• Pharmaceutical excipients – lactose, microcrystalline cellulose, starch, and mannitol powders
• Catalyst supports and adsorbents – alumina, silica, zeolites, and activated carbon particles
• Food and feed additives – salt crystals, sugar granules, dietary fibres, and vitamin premixes
• Construction and ceramic materials – sand, gravel, cement powders, and ceramic beads
• Environmental tracer particles – fluorescent microspheres, glass beads, and polymer markers for flow visualisation
• Metallic and ceramic powders – aluminium, titanium, and zirconia powders for additive manufacturing
• Agricultural and agrochemical granulates – fertiliser prills, seed coatings, and pesticide carriers

Particle Size and Shape Analysis – Granulometric Characterisation

• Laser diffraction particle size distribution (ISO 13320 / ABNT NBR 16399) – We use a laser diffraction analyser with a measurement range of 0.1 µm to 3 mm. The sample is dispersed in air or a suitable liquid medium, and the diffraction pattern is recorded to generate a volume‑weighted size distribution. We report the D10, D50, D90 values, the span, and the uniformity index. This method is essential for process control in Brazilian pharmaceutical and chemical manufacturing.
• Dynamic image analysis (ISO 13322‑2 / ABNT NBR 16125) – For irregular particles, we use a dynamic image analyser that captures high‑speed images of particles in free fall. The software calculates parameters such as circularity, aspect ratio, convexity, and Feret diameter. We provide the shape factor distribution and the percentage of elongated or angular particles. This is critical for flowability and compaction behaviour.
• Static image analysis (ISO 13322‑1) – for sub‑micron particles – Using a scanning electron microscope (SEM) coupled with automated image processing, we measure particle size and shape at the nanoscale (down to 50 nm). We report the number‑based mean diameter and the equivalent circular diameter. The micrographs are also used to detect agglomerates or surface irregularities.
• Sieve analysis (ASTM E11 / ISO 3310 / ABNT NBR 5734) – For coarser particles (≥ 38 µm), we perform dry or wet sieving using a set of calibrated stainless‑steel sieves, following the guidelines of USP <786>. We report the mass fraction retained on each sieve and the cumulative passing percentage, which is required for Brazilian construction materials and fertiliser certification.

Density, Porosity and Surface Area – Bulk and Particle-Level Properties

• True (particle) density by helium pycnometry (ISO 12154 / ASTM D5550) – We measure the true volume of the solid material by displacing helium gas in a calibrated pycnometer. The true density (g/cm³) is calculated from the sample mass and the displaced volume. This value is essential for interpreting sedimentation behaviour and for calculating the void fraction in packed beds. The measurement uncertainty is typically ±0.01 g/cm³.
• Bulk and tapped density (ISO 697 / ASTM D6393 / ABNT NBR 13853) – We pour the powder into a graduated cylinder and measure the mass‑to‑volume ratio without compaction (bulk density). Then we tap the cylinder mechanically until no further volume decrease occurs, and record the tapped density. The Hausner ratio (tapped/bulk) and Carr compressibility index are calculated, providing a reliable assessment of powder flowability – a critical parameter for Brazilian tablet compression and capsule filling processes.
• Specific surface area by BET (ISO 9277 / ASTM D4567 / ABNT NBR 17203) – Using nitrogen or krypton gas adsorption at 77 K, we measure the surface area of the particles based on the Brunauer‑Emmett‑Teller (BET) theory. We report the BET specific surface area in m²/g and the pore volume (if applicable). This is essential for catalyst supports and adsorbents, where high surface area correlates with higher activity.
• Mercury intrusion porosimetry (ISO 15901‑1 / ASTM D4284) – For porous particles, we determine the pore size distribution (2 nm to 200 µm), pore volume, and porosity. The median pore diameter and the total intraparticle porosity are reported. This data is critical for Brazilian pharmaceutical coatings and for selecting filter media.

Flowability and Handling Behaviour – Angle of Repose, Compressibility and Shear Strength

• Angle of repose measurement (ASTM D6393 / ISO 4324 / ABNT NBR 16196) – We pour the powder through a funnel onto a flat surface and measure the angle of the cone formed. The angle is recorded for both static and dynamic conditions. A smaller angle indicates better flowability – a key parameter for hopper design and pneumatic conveying in Brazilian industrial plants.
• Shear cell test for powder cohesion and wall friction (ASTM D6773 / ISO 15149) – We use a ring shear tester to measure the unconfined yield strength and the internal friction angle. The flow function (FF) is calculated to classify the powder as free‑flowing, easy‑flowing, or cohesive. We also measure the wall friction angle against common container materials (stainless steel, aluminium, plastic), which is essential for feed‑rate consistency and preventing segregation.
• Floodability and aeration test (ASTM D7891) – We assess the powder’s tendency to flood when aerated by measuring the aerated bulk density and the air retention. A high floodability index is reported for powders that may cause uncontrolled discharges, helping Brazilian engineers design appropriate dust‑control measures.
• Electrostatic charging tendency – friction charging test – We pass the powder through a defined tube of standard material (e.g., PTFE or steel) at controlled velocity and measure the charge‑to‑mass ratio (µC/g) using a Faraday cup electrometer. Excessive electrostatic charge may cause segregation or adhesion to equipment surfaces, and our report provides recommendations for mitigation.

Chemical Inertness and Compatibility – Reactivity and Leaching Assessment

• Chemical reactivity test with standard solvents and pH environments (ASTM D3682 / ISO 17294 adapted) – We expose the inert particles to a range of solvents (water, ethanol, hexane, acid and alkaline solutions) at elevated temperature (40‑60 °C) for a defined period (e.g., 7 days). After filtration, we analyse the leachate for any dissolved species using ICP‑OES or ion chromatography. The mass loss of the particles and the leached ion concentration are reported. A mass loss below 0.1 % over 7 days qualifies the material as “chemically inert” for most Brazilian food and pharmaceutical applications.
• Catalytic activity or interference testing – For catalyst supports, we perform a blank reaction test (e.g., decomposition of a model compound) to ensure that the inert particles do not introduce unintended catalytic effects. The conversion or yield is compared to a reference; any deviation greater than 2 % is flagged.
• Adsorption/desorption of active ingredients – For excipients used in drug formulations, we measure the adsorption capacity of a model drug (e.g., ibuprofen or caffeine) from aqueous solution and the subsequent desorption profile. The results are expressed as mg of drug per gram of particle, which is critical for controlled‑release formulations in Brazilian generic drug manufacturing.
• Thermal stability and decomposition onset (TGA/DSC) – Using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), we determine the temperature at which the particles start to decompose or undergo phase transitions. The decomposition onset temperature and the mass loss at 500 °C are reported, ensuring that the inert particles can withstand high‑temperature processes such as drying, sintering, or sterilization.

Environmental and Hygienic Properties – Microbial and Contaminant Testing

• Microbial load test for pharmaceutical and food‑grade particles (USP <61> / AOAC 991.14) – We test for total aerobic count, yeast and mould, and specific pathogens (E. coli, Salmonella, Staphylococcus aureus) following standard microbiological methods. Results are expressed as CFU/g and compared to the acceptance limits (e.g., ≤ 1,000 CFU/g for excipients). This is mandatory for ANVISA compliance in Brazilian food and drug products.
• Endotoxin test (LAL method) – for parenteral or inhalation applications – We perform the Limulus Amebocyte Lysate test to quantify bacterial endotoxin in EU/g or EU/mg, following USP <85> and ABNT NBR 16122. A value below 0.5 EU/mg is typically required for sterile products, and our report provides the measured endotoxin level with a clear pass/fail verdict.
• Heavy metal leaching and trace contaminant screening (USP <232> / ICH Q3D) – We digest the particles in microwave‑assisted acid and analyse for trace elements (Pb, Cd, As, Hg, Cr, etc.) using ICP‑MS. The results are compared to the permissible daily exposure limits for pharmaceutical and food products, ensuring compliance with Brazilian regulations.
• Fouling and cleaning verification – for process equipment – For particles used in cleaning validation studies (e.g., as soil mimics), we apply a known amount of particles to stainless steel coupons, perform a cleaning procedure, and measure the residual particles by gravimetry or HPLC. The cleaning efficiency percentage is calculated, helping Brazilian QC teams validate their cleaning protocols.

Report Acceptance & Compliance with Brazilian Pharmaceutical, Chemical and Environmental Standards

All inert particle experiments and characterisations described above are conducted under our ISO/IEC 17025:2017 accreditation, using calibrated instruments traceable to national and international standards (INMETRO, NIST). Our final test reports include: a detailed description of sample preparation and test conditions, raw data (particle size distributions, density values, surface area, flowability indices), graphical representations (histograms, cumulative curves, BET plots), statistical summaries (mean, standard deviation, confidence intervals), and a clear conformity statement against the client’s specified specification or reference standard. Where applicable, we also provide a measurement uncertainty (expanded uncertainty, k=2) for each key parameter. These reports are widely accepted by ANVISA for product registration and quality assurance, by INMETRO for metrological certification, by IBAMA for environmental impact studies involving particulate release, and by Brazilian manufacturers in the chemical, food, and advanced materials sectors for supplier validation, process scale‑up, and troubleshooting. Bilingual (Portuguese/English) versions are available to facilitate submissions to regulatory authorities and communication with international technical teams. With our comprehensive inert particle experimental service, you gain precise, actionable data to optimise your products and processes, ensuring that your particulate materials meet the highest standards of purity, stability, and performance for the Brazilian market.