Determination of N,N dimethyl formamide in micronazed gilibenclamide capsules by gas chromatography

OBJECTIVE To determine the content of N,N dimethyl formamide,the residual organic volatile solvents,in micronazed gilibenclamide capsules.METHODS Dissolved in dimethyl sulphoxide,2 μL sample solution was injected on a DB 1 (100% dimethyl polysiloxane) sillica capillary column using nitrogen as the carrier gas.Keep the initial temperature at 150℃ for 14 min,then it was raised to 200℃ at the rate of 40 ℃·min -1 ,sustained for 12 min.The injection port and FID detector were 210℃ and 240℃.Under this condition,N,N dimethyl formamide and the internal standard tetrahydrofuran were separated completeh.RESULTS The linear range of N,N dimethyl formamide was 35.19～28.15 μg·mL -1 ,and the LOD was 8.8 μg·mL -1 .The precisions was 1.9%.The recovery of N,N dimethyl formamide was 101.4%.Three batches of sample were analysed.CONCLUSION After validation,the method was proved to be accurate,sensitive and reliable.It is quite suitable to be used in the analysis of the N,N dimethyl formamide in micronazed gilibenclamide capsules.