Significance Of Ethylene Oxide Residue Detection

Significance of Ethylene Oxide Residue Detection

Ethylene oxide (EO) is an organic compound with a simple ring structure, chemical formula C2H4O. It is a toxic substance with strong penetrating and killing effects on various organisms such as bacterial spores, fungi, and viruses. EO is widely used in disinfection processes across industries such as textiles, pharmaceuticals, and medical devices.

The detection of ethylene oxide residue is crucial for enterprises using EO sterilization equipment for the production of non-medical devices. The use of EO can effectively kill various microorganisms at room temperature. However, due to its high toxicity to humans, strict requirements are imposed by industry standards on residual EO levels in disposable non-medical products.

The ethylene oxide residue detection apparatus (Gas Chromatograph) is applicable to all disposable medical products disinfected using EO sterilization equipment. Some listed products are:

• Disposable sterile syringes
• Blood transfusion products
• Plasma separation cups
• Leukocyte filters
• Blood bags
• Sterile urinary catheters
• Blood containers
• Protective masks
• Disposable protective clothing
• Soft tissue expanders
• Surgical dressings
• Medical cotton
• Implantable drug delivery devices
• Intravenous infusion sets
• Blood transfusion sets

The execution standards for ethylene oxide residue detection are:

• GB/T 14233.1-2008: Inspection methods for infusion, blood transfusion, and injection equipment - Part 1: Chemical analysis methods
• GB/T 16886.7-2001: Biological evaluation of medical devices - Part 7: Ethylene oxide sterilization residue

Ethylene Oxide Residue Detection by Gas Chromatography

1. Test Equipment: Gas Chromatograph
2. Testing Principle: Under certain temperature, extractant-water is used to extract the EO from the sample, and the EO content is determined using Headspace Gas Chromatography.
3. Preparation of Standard Stock Solution (Weighing Method):
   • Place approximately 50mL of water into a 50mL volumetric flask, stopper it, weigh precisely to 0.100g. Inject approximately 6mL of EO using a syringe, shake gently, cover tightly, reweigh. The difference between the two weights represents the weight of EO contained in the solution. Then dilute this solution to 1x10-2g/L to serve as the standard stock solution.
4. Test Method:
   • Take an appropriate amount of EO standard stock solution to prepare six standard solutions of different concentrations, take 10mL of each, and prepare six standard solution samples. When the standard solution reaches gas-liquid equilibrium, the gas at different concentrations corresponds to different gas concentrations. After reaching equilibrium, inject the gas into the sampler and record the peak height (or area) of EO. Then calculate the EO residue according to the formula based on the peak height (or area) corresponding to different concentrations.