Ethylene Oxide Content based on Simulated Use
This test is generally performed on devices that are not implanted or in use for extended periods, and analysis of the total EO content of the device may not be required. The test simulates clinical use of the device including temperature and time of exposure to tissue to determine the potential residual EO dose to a patient.
 

Ethylene Oxide Content Following Exhaustive Solvent Extraction
The test article is extracted repeatedly with the appropriate solvent (acetone or water are commonly used) and the EO content of the extracts is measured until either no more EO is found or until less than 10% of the EO found in the initial extract is detected. The sum of the EO detected in all of the extracts is reported.
 

Ethylene Oxide Content by Exhaustive Headspace Analysis
The test article is repeatedly heated in a sealed container and the EO content of the gaseous headspace is measured. Number of heatings, their duration and temperature are determined in accordance with AAMI guidelines. The sum of the EO detected in each of the heatings is reported.
 

Ethylene Glycol and Ethylene Chlorohydrin in Aqueous Extracts
Ethylene oxide can react with water to form ethylene glycol, and if chloride is present, ethylene chlorohydrin may also form. The reactions are pH, temperature and material dependent. Water extraction (either simulated use or exhaustive extraction) followed with gas chromatographic analysis is employed for determination of these two residual products.
 

Ethylene Oxide residuals analyzed according to ISO 10993-7

• Ethylene Oxide (aqueous extraction)
• Ethylene Oxide (solvent extraction)
• Ethylene Oxide (headspace)
• Ethylene Chlorohydrin (aqueous extraction)
• Ethylene Glycol (aqueous extraction)
  

Gas Chromatography

• Trace solvent analysis
• Contact lens residual monomers (HEMA, EGDM, MEHQ)
• Ethylene oxide gas mixture analysis
• Ethylene oxide sterilization chamber content analysis
• Development of gas chromatographic methods
• Residual glutaraldehyde analysis

High Performance Liquid Chromatography (HPLC)

• Quantitative and stability-indicating assays of pharmaceutical products using isocratic and gradient separations.
• Development and validation of HPLC methods using USP-defined principles

USP General Chapters Assays

• Identification Tests USP 191: Identification of a variety of anions and cations using non-instrumental methods.
• Arsenic Method I USP 211: This test is used to determine the presence of trace amounts of arsenic in inorganic materials.
• Heavy Metals USP 231: Total heavy metal (lead, mercury, bismuth, arsenic, antimony, tin, cadmium, sliver, copper and molybdenum) content is determined through visual comparison with known lead standards.
   - Method I This method is used unless otherwise specified in the USP monograph.
   - Method II This method is used when specified by USP for substances that interfere with heavy metal analysis by Method I.
• Residue on ignition USP 281
• Volatile Organic Impurity Assays USP 467: This method is generally used to look at solvent residuals that remain after drug production or purification processes.
• Physicochemical Tests, Plastics, USP 661: Extracts from plastics are evaluated using the complete battery of tests described in USP including nonvolatile residue, residue on ignition, heavy metals and buffering capacity
• Loss on drying USP 731
• Loss on ignition USP 733
• Melting Range or Temperature USP 741
• pH USP 791
• Specific Gravity USP 841

Refractive Index
Using an Abbe refractometer Spectrophotometric Scanning

• UV/Visible

Medical Device Cleaning Studies
The Moog Chemistry Department works with our Reusable Device group to design and perform cleaning studies. Cleaning efficacy may be determined by use of a total protein assay, or by other client-specified measures of contamination removal.