ABSTRACT
Objective To establish a stable and reliable method for the determination of ethylene oxide residue,and to analyze ethylene oxide residue in multi components made of different materials involved in some medical devices,so as to provide references for sample selection and ethylene oxide residue detection of multi-component medical device kits.Methods A method for the determination of ethylene oxide residue of multi-component medical devices was developed using headspace-gas chromatography and DB-WAX column under the conditions of headspace extraction with equilibration at 80℃ for 20 min,and the weighing mass,linearity,limit of detection,limit of quantification,precision and recovery of the method were determined.Trials of the method were carried out on the items undergoing ethylene oxide sterilization,including disposable perineal care kit,disposable gynecological examination kit,disposable suture dressing kit,disposable debridement kit and the components contacting human body in the disposable dialysis kit,and the abilities of different materials of the components were analyzed in absorbing,retaining and releasing ethylene oxide.Results The method showed high linearity(r=0.999 8)in the range of ethylene oxide mass concentration from 0.4 to 16.0 μg/mL with a weighing mass of 1.00 g,which had the limit of detection being 0.11 μg/mL,the limit of quantification being 0.37 μg/mL and the relative standard deviations(RSDs)for the precision from 0.35％to 1.52％.The average recoveries of different spiked amounts of ethylene oxide in the three blank matrices ranged from 92.68％to 101.42％with the relative standard deviations(RSDs)from 2.46％to 7.59％,which all satisfied the detection requirements.The components made of rubber and acrylonitrile-butadiene-styrene copolymer(ABS)in multi-component medical device kits had the highest ethylene oxide residues,followed by the components made of wood,degreased cotton,polypropylene and polystyrene.Conclusion The method proposed gains advantages in easy operation and high specificity,quantification and reproducibility,which can be used for the determination of ethylene oxide residue in the multi-component medical device kit undergoing ethylene oxide sterilization.References are provided for sample selection of multi-component medical devices.[Chinese Medical Equipment Journal,2024,45(1):56-61]
ABSTRACT
Objective To observe the effects of interleukin-1 ?(IL-1?) on spontaneous electrical activity of neurons in paravenrticular nuclei,and discuss the possible mechanism.MethodsExtracellular recording technique was employed to observe the effects of IL-1? on spontaneous electrical activity of neurons in paravenricular nuclei in rat hypothalamic slices,and the influence of losartan on the electrical activity induced by IL-1? was examined.ResultsAfter exposure to IL-1?(1?10-7 mol/L),the discharge frequency was significantly increased in 46 of the 59 discharge units(78%) of neurons(P