Study On Determination Of Methanol In Alcohol

This paper mainly studies the method of determination of methanol in alcohol.At present,methanol detection method has colorimetry,titration,biosensor,liquid chromatography,gas chromatography,gas chromatography is widely recognized as the method of methanol in the world.The optimal gas chromatography method was used to determine the content of methanol in alcohol by means of the method of direct injection of gas chromatography,internal standard method and topographic method..In this paper,the method for determination of methanol in liquor by gas chromatography direct injection method and hs-gc was studied and compared.Direct sampling method according to GB/T 5009.48 2003 sampling directly and according to GB 5009.266 2016 internal standard method,respectively,to the national standard method is improved and optimized.The optimum chromatographic conditions were established by optimizing the sampling quantity and heating temperature.The linear range of the three methods is 0.0232g/L ~ 1.288 g/L,and the linear correlation coefficient can reach above 0.999.The detection limit of direct injection external standard method is 7.5mg/L,and the range of the standard deviation is: 90%~ 110%,the relative standard deviation is < 1%,and the results of the method uncertainty are expressed as:(0.314 ±0.004)g/L and(0.942 ± 0.011)g/L.The detection limit of direct injection internal standard method is: 7.5mg/L,and the range of the standard recovery:95%~ 105%,relative standard deviation < 2%,the method uncertainty result is indicated:(0.0476 ± 0.008)g/L and(0.557±0.009)g/L.The detection limit of the top space method was 0.02 g/L,and the range of the standard recovery was: 90%~ 110%,relative standard deviation < 4%,and the results of the method uncertainty were expressed as:(0.304 ± 0.008)g/L and(0.950 ±0.013)g/L.The direct external standard method and the external standard method were used to determine the same liquor samples.The experimental results show that there is no significant difference between the laboratory and the laboratory.The content of methanol in 12 wines was determined by the best chromatographic conditions of the three methods,and the results of the three methods were not different.Direct injection external labeling method without pretreatment process,simple and fast precision;The direct injection method can be used to monitor the operation process and the interference caused by the instrument to make the quantitative results more accurate.The headspace injection method is small for the analysis personnel and the environment,the automation degree is high and the repeatability is good,the operation is simple,the three methods each have the advantage.The determination of methanol content in alcohol can be used flexibly.