Separation and Determination of Preservative Methylparaben in Insulin Preparations Using Gas Chromatography

Abstract

In this search an improved gas chromatographic method was used foridentification and typically quantitated for methylparaben(mp) which is used aspreservative in insulin preparations.it was involved the optimal conditions forextraction mp from aqueous samples with ethyl acetate ,chloroform ,and toluene asextractants,then analyzed by gas chromatography(GC).Effects of each of extractants polarity, aqueous samples pH, phases (organic toaqueous) ratio, mixing time, polarity of stationary phases, and column temperatureon efficiency of separation and determination of mp. were studied in this work.Synthetic sample which contained the same contents as a life sample wastested to omit interferings of other drug additives on analysis results.The extraction of mp. was (90-91)% with one batch of ethyl acetate and (99-100)%with two batches of ethyl acetate at pH medium(1.5-2).also the non-polarstationary phase(OV-101) is the best choice for determining mp by GC.The concentration of mp. in insulin preparations was within the acceptablerange(1.003mg/ml).The relative error (R.E) was ± (0,39-1.49)% and relative standarddeviation(R.S.D) was (1.21)% for life samples.