Detergent (Anionic Surfactant) Residue Determination

Medical Analyses

Detergent (Anionic Surfactant) Residue Determination

Determination of Detergent (Anionic Surfactant) Residues on Medical Devices

Pre-Treatment: Extraction • Determination: Gravimetric Method
ISO 2271 • ASTM F2459

1. Why Test for Detergent Residues?

During cleaning or reprocessing of medical devices, detergents containing anionic surfactants (e.g., SDS, SLES) may remain on the device surface. These residues may cause:

Cytotoxicity (cell membrane disruption)
Protein denaturation and inflammation
Interference with sterilization efficacy
Non-compliance with ISO 10993 biocompatibility requirements

2. Applicable Standards

Standard	Description
ISO 2271	Determination of anionic surfactants (gravimetric or MBAS method)
ASTM F2459	Extractable detergent analysis from medical device surfaces
ISO 10993-12	Sample preparation and extraction conditions
ISO 17664 / ISO 15883	Cleaning and decontamination requirements

3. Extraction Pre-Treatment

Parameter	Typical Condition
Solvent	Ultrapure water or 70:30 water:isopropanol
Temperature	37°C–50°C
Duration	30–60 minutes
Method	Stirring or ultrasonic extraction
Surface/Volume Ratio	1 cm² = 1 mL solvent

4. Gravimetric Determination (ISO 2271)

The extract is transferred into a pre-weighed dish
Solvent is evaporated at 105 °C
Residue is weighed
Result is expressed as mg/device or µg/cm²:

$Residue \\,(mg/device) = \\frac{(m_{final} - m_{initial})}{number \\,of\\, devices}$

5. Acceptance Criteria

Unit	Limit
mg/device	≤ 0.5 mg
µg/cm²	≤ 2 µg/cm²
Visual check	“No visible residue” (ASTM F2459)

6. Services by TTS Laboratory

✔ ISO 2271 gravimetric & MBAS analysis
✔ ASTM F2459 compliant extraction & validation
✔ Post-sterilization surface cleanliness verification
✔ Toxicological risk evaluation (ISO 10993-17)
✔ Documented reports for CE / FDA compliance