Study On Analysis By GC-MS And ICP-OES And Identification Model Of Three Kinds Of Famous Liquor

Chinese liquor is an indispensable drink in social intercourses,celebrations and weddings with a long history of five thousands of years and profound cultural connotation.It has a unique style features.The traditional identification of Chinese liquor mainly relies on the sensory evaluation of wine-tasters,and the accuracy is affected by emotion,taste environment and many other subjective or objective factors.The wine-tasters is insufficient to the large amount of Chinese liquor,and it is difficult to meet the needs of market supervision and identification.The Wuliangye Crystal Liquor,Shuijingfangg Wellbay liquor and 10 years Honghualang Liquor were chosen as the representative famous liquor.The organic components and inorganic elements were determined by GC-MS and ICP-OES,and the data was analyzed by Agilent Mass Profiler Professional and Matlab.Principal component analysis,Clustering analysis,Linear discriminant analysis,Partial least squares discriminant analysis and Support vector machine were used to established classification and prediction model for three kinds of famous liquor.The models of authentic identification of famous liquor were explored.(1)The determination conditions of liquor by GC-MS were optimized.The optimized chromatographic conditions were as follow: the flow rate was 1.0 mL/min and the split ratio was 5:1.the temperature program was: the initial temperature was set at 40°C for 5 min,then ramped to 100°C at a rate of 5°C/min and held for 5 min,and ramped to 190°C at a rate of 10°C/min and held for 20 min.The optimized MS conditions were: Electron impact ion source: EI,Electron energy: 70 eV,Ion source temperature: 230°C,Scanning mass range(m/z): 35 ~ 500.The precision of the method was experimented under the optimum GC-MS conditions.The retention time RSD(n = 6)of the n-amyl acetate was 0.1% and the RSD(n = 6)of the peak area was 3%.The results showed that the method had a good precision.(2)The accuracy,precision and detection limit of 9 kinds of metal elements(Ca,Na,K,Mg,Cu,Fe,Mn,Zn,Sr)were measured by ICP-OES.The correlation coefficient of the standard curve of each metal element ranged from 0.998 to 1.000,the recovery of standard ranged from 95% to 110%,the relative standard deviation(RSD,n = 6)was lower than 4.7%,the detection limit was less than 0.005 mg/L.The results show that the linearity,accuracy,precision and detection limit of 9 kinds of elements were satisfied with the analytical chemistry requirement.(3)The concentration of 9 kinds of metal elements in 175 liquor samples were determined by ICP-OES,and the metal element concentration characteristics of three famous liquor were analyzed.The results showed that the concentration of metal elements in the same varieties of liquor was relatively concentrated,it was less than the difference between the different varieties.The concentration of metal elements in the three famous liquor had its own characteristics.The concentration of Ca and Mg in Wuliangye crystal were the lowest,and the average concentration was as low as 2.10 mg/L and 0.32 mg/L,respectively.The concentrations of Ca,Mg and Sr in the Shuijingfangg Wellbay were significantly higher than those of the Honghualang samples while the concentrations of K,Mn,Cu and Fe were consistent.The concentration of 9 kinds of metal elements between the 10 years Honghualang,15 years Honghualang and 20 years Qinghualang samples was highly consistent.(4)The GC-MS and ICP-OES data of 16 groups Wuliangye crystal liquor and 11 group of the same factory,13 group of origin samples were analyzed by principal component analysis.The results showed that all Wuliangye crystal samples gathered in a small area and tended to overlap to the same factory samples.It showed that the organic components and inorganic metal concentration of the 16 groups of Wuliangye were high degree of uniformity,and those were similar to some same factory samples.The results of cluster analysis based on GC-MS data showed that 16 groups of Wuliangye were divided into two parts,14 of which were together with 2 groups of the same factory samples,and other 2 groups were clustered together with 1 group of Yibin samples.The analytical results of GC-MS and ICP-OES of Wuliangye crystal liquors were consistent.(5)The GC-MS and ICP-OES data of 20 groups of Shuijingfang Wellbay and 18 groups of the same factory,23 groups of origin samples were analyzed by principal component analysis.The results showed that the organic components and inorganic metal concentration of Shuijingfang Wellbay were consistency and similar to the same factory samples.But the data were significantly different from the liquor samples of Chengdu.The difference between the ICP-OES data of the Shuijingfang Wellbay and the liquor samples of Chengdu was less than that of GC-MS.The results of cluster analysis showed that the samples of 20 groups of Shuijingfang were divided into four parts,which were clustered together with similar samples of the same factory/origin liquors.The consistency of Shuijingfang liquors was less than Wuliangye crystal liquors because the production date presented a wider range.(6)The GC-MS and ICP-OES data of 19 groups of 10 years Honghualang liquors and 20 groups of the same factory,11 groups of origin samples were analyzed by principal component analysis.The results showed that the organic components and inorganic metal concentration of 10 years Honghualang were consistency and similar to 15 years Honghualang and 20 years Qinghualang samples.But the difference from the liquor samples of Gulin was obvious.The results of cluster analysis based on GC-MS data showed that 13 of the 19 groups of 10 years Honghualang liquors clustered together and the other 6 groups clustered with similar samples.The results of cluster analysis were in agreement with the results of principal component analysis.The organic components and inorganic metal of 10 years Honghualang,15 years Honghualang and 20 years Qinghualang were high similarity because these all belonged to Langjiu liqour varieties with a high degree of production materials,brewing process,fermentation methods,blending methods.(7)Three kinds of famous liquor classification prediction models based on GC-MS,ICP-OES and GC-MS-ICP-OES data was established respectively.Models had been verified by the samples not involved in model buliding.The results showed that the model based on GC-MS-ICP-OES data were better than those based on the GC-MS or ICP-OES data.And it had higher cross validation accuracy and overall prediction accuracy.The accuracy of cross validation and overall prediction of W-Combin-LDA of Wuliangye crystal liquor were 94.1% and 94.6%,respectively.The accuracy of S-Combin-LR of Shuijingfang Wellbay were 90.4% and 99.1% respectively,and the accuracy of L-Combin-SVM of 10 years Honghualang were 93.18% and 95.2%,respectively.