Raw Material Characterization Screening: Methods & Laboratory Services
Aerospace corrosion testing per MIL-STD-810 evaluating alloy and coating protection performanceWhat Is Raw Material Characterization Screening?
Raw material characterization screening is a systematic analytical process applied to incoming materials before they enter a manufacturing process. It verifies that the material received from a supplier matches the specified composition, purity, physical properties, and identity, and that it is free from unacceptable levels of impurities, contaminants, or adulterants.
Effective raw material screening is the first line of defense in quality assurance, preventing defective or non-conforming materials from entering production and causing costly downstream failures. It is a critical requirement across the pharmaceutical, plastics, metals, electronics, and specialty chemicals industries.
Why Raw Material Characterization Is Critical
Raw material variability is one of the leading causes of production quality problems. Even materials from approved suppliers can vary between lots due to changes in feedstock, process, or transport conditions. Without systematic incoming screening, these variations propagate into finished products, potentially causing:
- Mechanical property failures in molded or machined parts
- Chemical incompatibilities in drug formulations
- Electrical property shifts in insulating or conducting materials
- Corrosion or degradation in service
A structured raw material screening program catches these variations at the earliest, most economical intervention point.
Key Components of a Raw Material Characterization Screen
Identity Testing (ID Test)
Confirms that the material received is the correct substance. Methods include:
- FTIR spectroscopy: Matches the infrared spectrum of the received material against a reference library or approved supplier spectrum. Rapid and non-destructive—suitable for 100% lot screening.
- Raman spectroscopy: Non-destructive identification through sealed containers or packaging.
- NMR spectroscopy: Definitive structural identification for complex organic materials.
Purity and Assay Testing
Quantifies the concentration of the primary substance and detects impurities:
- HPLC/GC: Quantitative assay and organic impurity profiling
- ICP-MS/ICP-OES: Elemental impurity analysis
- Titration: Acid/base assay for simple inorganic compounds
Physical Property Testing
Verifies that physical characteristics match specification:
- Particle size distribution (laser diffraction, ASTM B822 for metals)
- Density (pycnometry, ASTM D792)
- Viscosity (for liquid raw materials, ASTM D445)
- Melt flow index (for polymer pellets, ASTM D1238)
- Moisture content (Karl Fischer titration, loss on drying)
Thermal Characterization
DSC (ASTM E1356, ISO 11357) confirms:
- Melting point / melting range (identity confirmation)
- Glass transition temperature (for polymer raw materials)
- Purity by melting point depression (pharmaceutical)
- Oxidative induction time (antioxidant level in polyolefins)
Microbiological Testing (Pharmaceutical and Medical)
For pharmaceutical raw materials: total aerobic microbial count (TAMC), total yeast and mold count (TYMC), and absence of specific pathogens (E. coli, Salmonella, Staphylococcus aureus) per USP <61> and <62>.
Building an Effective Incoming Material Screening Program
| Step | Action |
| Supplier qualification | Audit, approve, and qualify suppliers before sourcing |
| Specification development | Define acceptance criteria for all critical quality attributes |
| Method validation | Validate test methods to ensure they reliably detect non-conformances |
| Sampling plan | Define lot sampling based on risk (supplier history, criticality) |
| Certificate of Analysis (CoA) review | Verify supplier CoA against specification before testing |
| Reduced testing for qualified suppliers | Use skip-lot or identity-only testing for proven, consistent suppliers |
Why Choose Infinita Lab for Raw Material Characterization Screening?
Infinita Lab offers comprehensive raw material characterization screening services across its nationwide accredited laboratory network. From FTIR identity testing and ICP elemental analysis to DSC thermal profiling and microbiological testing, we provide fast, reliable results with full traceability to support your incoming quality program.
Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090 to learn more about our services and how we can support you. Request a Quote
Frequently Asked Questions (FAQs)
How quickly can FTIR identity testing be performed on incoming raw materials? FTIR identity testing using an ATR (attenuated total reflectance) accessory can be performed in 2–5 minutes per sample with minimal or no sample preparation. It is the fastest and most widely used method for 100% incoming identity screening of polymer pellets, excipients, active ingredients, and chemical raw materials.
What is the difference between a Certificate of Analysis (CoA) review and actual incoming testing? A CoA is a document from the supplier stating that the lot meets specification based on their own testing. CoA review checks that the documented values are within specification but does not independently verify the material. Actual incoming testing provides independent, verifiable confirmation that the received material matches the CoA claims.
How is risk used to prioritize raw material testing scope? Higher-risk materials—those with history of variability, those from new or unqualified suppliers, those with direct patient or safety impact—receive full characterization testing. Lower-risk materials from consistently performing, qualified suppliers may require only identity testing and CoA review. Risk-based testing reduces cost while focusing effort where it matters most.
What is "skip-lot testing" and when is it appropriate? Skip-lot testing reduces the testing frequency for well-qualified suppliers whose materials have a long history of conformance. After a defined number of consecutive passing lots, every second or third lot is tested rather than every lot. Skip-lot programs require documented supplier qualification, statistical performance history, and a plan to return to full testing if a failure occurs.
Can raw material screening detect counterfeit or adulterated materials? Yes. FTIR, NMR, and HPLC are effective at detecting adulterated or counterfeit materials where a substitute substance has been used in place of the specified material. Elemental analysis detects heavy metal adulteration. Thorough characterization screening is the primary defense against adulteration in pharmaceutical and food ingredient supply chains.
