Development and Validation of a Canister Method for Measuring Ethylene Oxide in Ambient Air

Abstract

A sampling and analytical method for measuring ethylene oxide (EO) in ambient air was developed and evaluated. The method is based on the use of evacuated canisters and gas chromatography-mass spectrometry (GC-MS). The objectives of this work were to characterize the performance of the method with respect to the following: (1) stability/recovery of ethylene oxide in a canister over a 15-day holding time; (2) detection capability; and (3) measurement of EO in an ambient air matrix. Both electropolished and silica-lined stainless steel canisters were evaluated in this study. The method evaluation involved both laboratory and field tests. The recovery of the EO was evaluated both on an absolute basis and relative to a spiked internal standard of toluene. EO spiked at levels of 2 ppbv and 20 ppbv was found to be stable for holding times of up to 15 days at 25 degrees C in both a humidified nitrogen matrix and in ambient air. The detection limit of the method was found to be 0.25 ppbv using EPA's traditional approach of seven replicate analyses of a low-level standard and 0.20 ppbv using a probability-based approach. EO recoveries in the laboratory stability study generally were 100 +/- 25%, and did not vary by canister type, nor did the EO recoveries decrease with holding time. Field studies demonstrated that the method is capable of detecting EO (as well as benzene and toluene) in an ambient air matrix.

Analysis of gaseous toxic industrial compounds and chemical warfare agent simulants by atmospheric pressure ionization mass spectrometry

“…5 Pre-concentration prior to analysis, normally necessary for ultra low-level analytes employs solid phase extraction (SPE), solid phase microextraction (SPME), or sorbent trapping. [6][7][8][9][10][11][12][13][14][15] These disadvantages, including long analysis time, 16 the possibility of requiring specially trained personnel, 1 and the potential for sample contamination 17 make these techniques less desirable for field analysis.…”

“…Mass spectrometry has obvious disadvantages as a portable, in situ instrument for the detection of hazardous compounds, given the size of the instrumentation, but this limitation is systematically being lifted by development of new, smaller mass spectrometers. [19][20][21][22][23][24][25][26][27][28][29][30][31] Aside from this, it is especially attractive, due to its general applicability, high sensitivity (as little as 1 part in 10 12 , ca. 10 215 g in favorable cases, even from complex mixtures 32 ) and high selectivity, particularly when using tandem mass spectrometry.…”

Validation of an Evacuated Canister Method for Measuring Part-Per-Billion Levels of Chemical Warfare Agent Simulants

“…Eklund et al 9 developed and validated a sampling and analytical method to measure ethylene oxide in air using evacuated SUMMA and fused silica-lined (FSL) stainless-steel canisters. The method evaluation involved laboratory and field tests.…”

Trace Measurements of Ethylene Oxide Using Cavity-enhanced Absorption Spectrometry near 3066 cm–1

“…This limitation can be partially overcome by minimizing leaks, using a longer column, and exploiting other m/z peaks at 15, 41 -43 and 56; however, this reduces the sensitivity of the analysis, making it unable to quantify low levels of EtO. An extensive study (Eklund et al, 2004) of ethylene oxide monitoring using EPA Method TO-15A showed that Summa canister samples filled with dry nitrogen are stable for up to 15 days and can provide EtO detections limits of 0.25 ppb, which is approximately 10 -20 times higher than the EPA targets noted above. Moreover, EtO production was observed in blank canisters filled with humid air at 50% relative humidity (Hoisington and Herrington, 2021).…”