Study On The Method For Determining Methanol In Edible Wine Using Chromatography

A simple and rapid analytical for determining methanol in edible wine is introduced in the paper .The study includes: Stationary phase selection, column preparation; Optimization of operational conditions for selected column ;The study on the conditions of static-head-space-sampling; Synthetic evaluation to Gas Chromatographic method of ODPN column. The result suggested that it is feasible to determine methanol in edible wine.Through comparing three stationary phase (ethyleneglycol, di-glycerol, and ODPN), the result suggested that ODPN is the best one for analysing methanol in edible wine, which can be used in lower temperature and it has a wider using temperature range(20-48℃). The content of ODPN in chromatographic column prepared, which obtained through the comparable study of several content of stationary phase, is determined by 10%. The optimal chromatographic conditions as following: velocity of nitrogen, hydrogen and air is 35ml/min,25 ml/min, and 300 ml/min respectively; temperature of column and vaporing chamber is 45,100 respectively; temperature of detector is 120℃.Through the study of static-head-space-sampling; optimal operational conditions as following: equilibrium temperature at ambient temperature, equilibrium time 10 minutes, salting out agent sodium chloride and it's concentration is 7.5g/100ml, the volume of head space gas injected in one time is 1.0ml.The Gas Chromatographic method we obtained through the study is better to determine methanol in edible wine (R>1.4), chromatographic peak is clear, datum line is straight; and it only need 7.55min for one sample, the analytical rate of this method is 2.5 , 2.42 and 2.28 times faster than that of directly-liquid-sampling ODPN column , DNP-Tween (rapid) column and GDX-102 column t respectively . Addition , the range of methanol concentrations that the method can measure is from 0.01g/100mL to 0.06g/100mL(the minimum detectable concentrations is from 1.8x10-4 to 9.0x10-4 g/100mL), the reappearance of this method is good (coefficient of variation is 1.14%~3.76%) and the accuracy is high (the average recovery rate is 98.48%). there is no significant difference among the determining results of DNP-Tween, GDX-102 and ODPN column when they were used to analyze severalsamples, but there is significant difference between ODPN column and magenta sulfurous acid colorimetric analysis and the result of the latter is higher than that of the former. The influence of sampling numbers of times to results can be overlook when the sampling numbers of times is less four times to one sample , and the influence of alcohol's concentration isn't obvious ; the way is simple and easy to operate.