PSS AccuSizer FX Optical Particle Counter
| Brand | Particle Sizing Systems (PSS) |
|---|---|
| Origin | USA |
| Model | AccuSizer FX |
| Instrument Type | Optical Particle Counter |
| Detection Range | Down to 150 nm |
| Maximum Concentration | 10⁷ particles/mL |
| Automation | Full auto-sampling and on-line dilution |
Overview
The PSS AccuSizer FX Optical Particle Counter is a high-precision, single-particle optical sensing (SPOS) instrument engineered for direct, quantitative particle counting and sizing in liquid suspensions. Unlike ensemble-based techniques such as dynamic light scattering (DLS) or laser diffraction, the AccuSizer FX employs light extinction detection—where individual particles passing through a focused laser beam generate discrete voltage pulses proportional to their cross-sectional area. This principle enables statistically robust, number-weighted particle size distributions with exceptional resolution in the submicron regime, particularly critical for detecting low-abundance aggregates in biopharmaceutical formulations or monitoring process-critical particulates in high-concentration slurries.
Key Features
- Single-Particle Optical Sensing (SPOS) Architecture: Delivers true number-based distribution with sensitivity down to 150 nm, resolving rare but clinically significant subvisible protein aggregates (e.g., dimers, trimers, and larger oligomers) that ensemble methods often mask.
- Full Automation Workflow: Integrated autosampler supports unattended analysis of up to 96 samples; built-in precision dilution module enables real-time, programmable dilution for samples exceeding the upper concentration limit (up to 10⁷ particles/mL), eliminating manual handling errors and ensuring reproducibility across batches.
- Robust Fluidic Design: Chemically resistant wetted path (PEEK, sapphire, and fused silica) accommodates aggressive solvents, acidic/basic buffers, and viscous formulations without degradation or carryover—validated for use with monoclonal antibodies, mRNA-LNPs, catalyst slurries, and ceramic pastes.
- Calibration Traceability: Factory-calibrated using NIST-traceable polystyrene latex (PSL) standards; optional user-performed verification with ISO 21501-4 compliant reference materials ensures ongoing metrological integrity.
- Regulatory-Ready Architecture: Firmware and software architecture supports audit trails, electronic signatures, and user access control—designed to align with FDA 21 CFR Part 11, EU Annex 11, and ICH Q5A/Q5C requirements for quality control laboratories operating under GMP/GLP environments.
Sample Compatibility & Compliance
The AccuSizer FX is validated for aqueous and organic-phase dispersions with refractive index differentials ≥ 0.02 relative to the dispersant. It routinely analyzes protein therapeutics (IgG, insulin, fusion proteins), viral vectors, lipid nanoparticles, pigment dispersions, and abrasive slurries used in CMP processes. All hardware components comply with RoHS and CE directives. Data acquisition and reporting modules conform to ASTM E2456–23 (Standard Practice for Reporting Particle Size Analysis Results) and ISO 13322-2:2022 (Imaging methods — Part 2: Dynamic image analysis). Optional IQ/OQ documentation packages are available for installation and operational qualification per pharmaceutical commissioning protocols.
Software & Data Management
AccuSizer Software v8.x provides intuitive method setup, real-time data visualization, and automated report generation in PDF/CSV formats. The platform includes statistical tools for trend analysis (e.g., % particles >5 µm per USP ), batch comparison overlays, and configurable pass/fail criteria based on internal specifications or regulatory thresholds. All raw pulse data and metadata—including timestamp, flow rate, dilution factor, and calibration ID—are stored in an encrypted SQLite database with immutable audit logs. Export interfaces support LIMS integration via ASTM E1394 or HL7-compliant protocols, enabling seamless data transfer into enterprise quality management systems (QMS).
Applications
- Biopharmaceutical QC: Quantification of subvisible particles in final drug product vials per USP , , and ; stability-indicating assay for aggregation kinetics during accelerated studies.
- Advanced Materials R&D: Characterization of nanoparticle dispersion homogeneity in battery cathode slurries, quantum dot inks, and metal-organic framework (MOF) suspensions.
- Medical Device Manufacturing: Verification of filter integrity and downstream particulate shedding from silicone tubing, IV sets, and prefilled syringe components.
- Academic & Regulatory Research: Reference-grade particle counting for method development, inter-laboratory comparison studies, and reference material certification.
FAQ
What detection principle does the AccuSizer FX use?
It utilizes single-particle optical sensing (SPOS) based on light extinction, not light scattering—enabling accurate sizing and counting of individual particles in the 150 nm – 2500 µm range.
Can it analyze undiluted high-concentration slurries?
Yes—the integrated microfluidic dilution system automatically adjusts sample concentration in real time to maintain optimal signal-to-noise ratio without manual intervention.
Is the system compliant with FDA 21 CFR Part 11?
Yes—software features electronic signatures, role-based permissions, and tamper-evident audit trails meeting Part 11 requirements for electronic records and signatures.
How is calibration verified during routine operation?
Users may perform periodic verification using certified PSL standards traceable to NIST; calibration status is logged with each analysis and included in final reports.
Does it support non-aqueous solvents such as DMSO or THF?
Yes—provided the fluidic path compatibility is confirmed; PEEK and sapphire components resist common organic solvents, and alternative wetted material options are available upon request.
