Ethylene Oxide plus solvents: An Application Note

7/28/2019 Ethylene Oxide plus solvents: An Application Note

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PID GC-301C APPLICATION NOTE #102: ETHYLENE

OXIDE + SOLVENTS May 20101

GC-301C

Application

Note #102

Ethylene Oxide

+ solvents

ETHYLENE OXIDE @ PPB LEVELS IN THE PRESENCE OF 1,000 PPM SOLVENTS FACEBOOK.COM/PIDANALYZERS

This application note concerns the

detection of ethylene oxide in workplace

atmospheres where a number of gases &

solvents coexist. The OSHA Permissible

Exposure Limit (PEL) for ethylene oxide

(ETO) is 1.0 ppm since ETO may causecancer. The recommended method for

ETO is Gas Chromatography

(GC)/Photoionization Detector (PID)

(OSHA Method 1910.1047 App D).

This was a manufacturing application

where more than 25 solvents were

present including alcohols, ketones,

aldehydes, aliphatic and aromatic

hydrocarbons. We tested the 301C GC

with a PID (10.6 eV) with solvents > 100

times the ETO concentration. With our

normal pre column, we could separatemany of the solvents. Fig. 1 is the

chromatogram for ETO (30M x 0.32

mmm capillary column) with 1,000 ppm

ethanol and 10 ppm ETO with our

normal precolumn. Note that ETO and

ethanol are separated but the ethanol

peak is off scale. With our novel

precolumn, shown in Fig. 2, the

ethanol peak is

totally eliminated. None of the other

solvents tested produced any peaks but

several had impurity peaks that were

resolved by the analytical column.

After the injection, the precolumn wasbackflushed to prevent any high MW

peaks from interfering with the next run.

The Peak Works software has a

programmable sample ahead feature

that starts sampling the next point as

soon as the sample is injected on the

column. This means that the analytical

time is the time per point.

All of the data including the

chromatogram is saved on an 8 GByte

memory stick. For more info, see the

GC301C brochure. 

Fig. 1 ETO and 1,000 ppm Ethanol with

normal + special precolumns

The lower chromatogram is 10 ppm ETO

1,000 ppm Ethanol. Note that the large p

is well separated from the ETO but with

special precolumn (upper) the 1000 ppmblocked from the analytical column an

there are no peaks from the solvent.

Written by: Dr. Jack Driscoll, PID Analyzers, LLC, 2 Washington Circle, Sandwich, MA 02563 T: 774 413 5281