Analysis of ethylene oxide based on headspace HS-25 and Panol GC1949

Abstract

In this paper, based on the self-developed fully automatic headspace sampler HS-25 and 1949 GC for the analysis of ethylene oxide, the FID detector was used. The limit of quantiation was as low as 0.15ug/g, and the standard recovery was within 98% ~ 119%.The following are detailed descriptions of the establishment of standard curve, method verification and other contents.

Introduction

GBT 14233.1-2008 Test Methods for Medical Infusion, transfusion and injection apparatus Part 1: Chemical Analysis Method specifies the determination of ethylene oxide residues by GC.Masks used by the public shall conform to the standards of "Medical Masks for Single Use" (YY/T0969-2013) "Medical Surgical Masks" (YY 0469-2011) and Technical requirements for medical protective Masks (GB 19083-2010). Protective clothing shall meet the standard of GB19082-2009C Technical Requirements for Medical disposable protective Clothing, which stipulates that after sterilization by ethylene oxide, the residual amount of ethylene oxide shall not exceed 10ug/g.GB/T 16886.7-2015 "Biological evaluation of medical devices Part 7: Ethylene oxide sterilization residue "GB 15979-2002" Hygiene standard for disposable health products "G/T15980-2009" Hygiene standard for disposable medical products "in the provision of medical products after ethylene oxide disinfection or sterilization factory, ethylene oxide residue should meet the corresponding product national standards or industry standards.

In this paper, the chromatograph 1949 and the self-developed automatic headspace sampler HS-25 were used to establish the analytical method.

Principle of method

The sample is placed in a sealed headspace vial. Under a certain temperature and pressure, the volatile components of the sample in the headspace vial volatilize to the liquid space, resulting in vapor pressure, and the gas-liquid phase reaches thermodynamic dynamic equilibrium. Within a certain concentration range, the concentration of ethylene oxide in the gas phase is proportional to that in the water phase.The quantitative extraction of the gas phase part was separated by GC, detected by hydrogen flame ionization detector(FID), qualitative according to the retention time, quantitative by standard curve external standard method.

Instruments and reagents

GC: PANNA Model 1949 GC with FID detector

Chromatographic column: -1 capillary column 30m×0.32mm×1.0µm

Headspace Sampler: Automatic headspace sampler HS-25 (Changzhou Panyu Instrument Co., LTD.)

Standard sample solution: ethylene oxide standard solution 5000µg/ml (methanol solution) 

General laboratory commonly used equipment, reagents

Analysis steps

1. Analysis conditions:

Headspace: Heating balance temperature 80℃, valve/quantitative ring temperature 85℃, transmission line 150℃, heating balance time 30min, GC analysis time 8min, injection time 2min, compression pressure 20psi, quantitative pressure 4psi, small flow purge 50ml/min before injection, large flow purge 200ml/min after injection, Purging time 1min, sample plate oscillation level 0.

GC: Column HP-innowax 30m*0.32mm*0.25μm, inlet 250℃, constant flow 1ml/min, initial temperature 80℃, hold for 8min. Shunt injection, shunt ratio of 10, detector 250℃, hydrogen 30ml/min, air 300ml/min, make up gas 25ml/min.

2. Calibration curve drawing:

10ug/ml reserve liquid: Absorb 100ul of 5000mg/ul ethylene oxide standard liquid into 500ml volumetric bottle, and fill to the scale with pure water.

(1) Add 0.5ml 10ug/ml standard solution into 20ml headspace vial, and add 4.5ml pure water to seal and mark the concentration as 1ug/ml

(2) Add 1ml of 10ug/ml of standard liquid into 20ml of headspace vial, and add 4ml of purified water into the sealed labeled concentration of 2ug/ml

(3) Add 2ml of 10ug/ml of standard liquid into 20ml of headspace vial, and add 3ml of purified water into the sealed labeled concentration of 4ug/ml

(4) Add 3ml 10ug/ml standard solution into 20ml headspace vial, and add 2ml purified water seal labeled concentration of 6ug/ml

(5) 4ml 10ug/ml standard solution was added into 20ml headspace vial, and 1ml purified water was added with 8ug/ml sealed concentration

(6) Add 5ml 10ug/ml standard solution into 20ml headspace vial with marked concentration of 10ug/ml

6 concentration samples were put into the instrument and measured according to the above analysis conditions. The typical spectrum of ethylene oxide is shown in Figure 1:

Figure 1 Spectrogram of 2ug/ml

Test results

Figure 2. Calibration diagram of ethylene oxide

1. Calibration curve:

Ethylene oxide calibration curve and linear correlation coefficient, detection limit (3 times signal-to-noise ratio), limit of quantitation (10 times signal-to-noise ratio) see the table below.

It can be seen from the above table that the correlation coefficient of ethylene oxide reaches 0.99989, with good linearity.

2. Determination of the lower limit concentration spectrum:

FIG. 3 Spectrum of 0.15ug/ml

3、Repetitive spectrogram:

2.5ug/ml repeatability spectrogram (n=7), repeatability 0.97%

Figure 4 Repeatability spectrogram of 2.5ug/ml

Test data sheet

4. Sample test spectrum:

A brand of mask was cut into pieces of 0.5mm×0.5mm, weighed 1g and put 5ml purified water into a headspace vial for testing, and the test result was 0.032ug/g

Figure 5 Ethylene oxide in the mask

5. Labeling and recovery:

1ug/ml and 4ug/ml have been added to the label recovery, respectively measured 4 times, the results are as follows: