Round‐robin evaluation of a solid‐phase microextraction–gas chromatographic method for reliable determination of trace level ethylene oxide in sterilized medical devices

Abstract

Medical devices that are sterilized with ethylene oxide (EtO) retain small quantities of EtO residuals, which may cause negative systemic and local irritating effects, and must be accurately quantified to ensure non-toxicity. The goal of this round-robin study is to investigate the capability of a novel solid-phase microextraction-gas chromatographic (SPME-GC) method for trace-level EtO residuals analysis: three independent laboratories conducted a guided experiment using this SPME-GC method, in assessing method performance, ruggedness and the feasibility of SPME fibers. These were satisfactory across the independent laboratories, at the 0.05-5.00 ppm EtO range. This method was then successfully applied to analyze EtO residuals in several sterilized/aerated medical devices of various polymeric composition, reliably detecting and quantifying the trace levels of EtO residuals present ( approximately 0.05 ppm EtO). SPME is a feasible alternative for quantifying trace-level EtO residuals in sterilized medical devices, thereby lowering the limit of quantification (LOQ) by as much as two to three orders of magnitude over the current GC methodology of direct liquid injection.

Optimization of a novel headspace–solid‐phase microextraction–gas chromatographic method by means of a Doehlert uniform shell design for the analysis of trace level ethylene oxide residuals in sterilized medical devices

“…This CAR-PDMS SPME fiber mixed-phase coating, which possesses complementary properties in contrast to lone PDMS, functions by means of adsorption, and thus is more generally apt for extracting high-capacity VOC with higher distributions constants (Dron et al, 2002) such as EtO, as applied in similar studies (Harper et al, 2008;Ayoub et al, 2002;Tsai and Wu, 2003;Tsai et al, 2004). Moreover, for such gas-phase analytes that naturally possess high Henry's constants, their natural convection is enough to facilitate rapid equilibration onto the CAR-PDMS SPME fiber (Pawliszyn, 1997).…”

“…However, there are very few publications on the analysis of EtO using HS-SPME. Of the few studies cited, both Harper et al and Ayoub et al used DI-SPME whereas Tsai et al focused on an indirect approach involving on-fiber derivatization with HBr for analyzing EtO (Harper et al, 2008;Ayoub et al, 2002;Tsai and Wu, 2003;Tsai et al, 2004).…”

“…Some EtO-sterilized medical devices may retain trace quantities of EtO residuals even after controlled aeration at levels that cause local irritation in patients (Harper et al, 2008). Direct liquid injection gas chromatography (GC) analysis (Sandra et al, 2002) of acetonebased exhaustive extractions or conventional headspace (HS) analyzer-based sampling is still widely employed to analyze EtO residuals found in medical devices (AAMI, 1995;Marlowe et al, 1987;Gramiccioni et al, 1985).…”

“…Ethylene oxide (EtO) is frequently used for sterilizing medical devices, especially for those devices that cannot be sterilized by steam, dry heat or ionizing radiation (Harper et al, 2008). Some EtO-sterilized medical devices may retain trace quantities of EtO residuals even after controlled aeration at levels that cause local irritation in patients (Harper et al, 2008).…”

Chemical Characterization and Non-targeted Analysis of Medical Device Extracts: A Review of Current Approaches, Gaps, and Emerging Practices

“…GC/MS is a technique used for the analysis of VOC and SVOC analytes in extracts. ,,,− The first stage of GC/MS analysis is the introduction of the sample to the analytical system. Typically, direct injection methods where the sample is loaded in liquid form are used, although alternative sample introduction methods may be selected to suit the chemical space, including static headspace, ,, solid phase microextraction (SPME), , dynamic headspace, and thermal desorption . For example, headspace GC/MS (HS-GC/MS) methods are reported for the characterization of volatile device constituents including residual processing solvents and sterilization agents. , HS-GC/MS may be performed on an aqueous extract or directly on a solid test article .…”