紫外光谱法快速测定生物质乙醇/水水解液中糠醛和5-羟甲基糠醛含量

摘要

木质纤维类生物质水解过程中产生的可溶性木素、呋喃类化合物在紫外波长范围内均有吸收峰,且吸收峰相互叠加。研究提出了一种基于紫外光谱法快速测定生物质水解液中糠醛(F)和5-羟甲基糠醛(5-HMF)混合物(M)的方法。研究发现,M中5-HMF的含量百分率(W5-HMF)和最大吸收波长(λmax)存在良好的线性关系,R2=0.9984。进一步研究表明 M中 W5-HMF不变时,混合物浓度(cM )和吸光度值(A)之间也存在良好的线性关系,R2在0.9986~1.0000之间,且重现性均良好。因此,基于A,cM 及λmax ,W5-HMF之间的良好线性关系,可以准确地检测出F和5-HMF的含量,其相对偏差、回收率及RSD分别为5.6%和3.7%,89%~96%,0.21%~0.85%。该方法简单、快捷、准确,适应于乙醇法精炼木质纤维类生物质水解液中 F和5-H MF混合物的测定。%The soluble lignin and furan compounds in hydrolysate of lignocellulose biomass have absorbed peaks and inter-super-impose in UV spectroscopy.Therefore,this paper developed a method for the determination of furfural and 5-hydroxymethyl furfural in ethanol-water refining liquors of lignocellulose biomass based on UV spectroscopy.The study showed that there is a good and linear relationship between maximum absorption (λmax)and the concentration percent of 5-HMF (W5-HMF)of M,the re-gression coefficient up to 0.998 4 (R2=0.998 4).Furthermore,a better linear relationship was also observed between the con-centration of mixture (cM)and absorptivity (A)when the W5-HMF was constant,the R2 of 0.998 6~1.000 0 and reproducibility are desirable.The contents of F and 5-HMF could be calculated accurately according to the perfect liner relationship of A and cM,λmax andW5-HMF,and the relative deviation of F and 5-HMF of 5.6% and 3.7%,recovery of 89%~96%,RSD of 0.21%~0.85%,respectively.Overall,The simple rapid and precise method in this paper can be applied to the determination of the F and 5-HMF in the hydrolysate of ethanol-water refining lignocellulose biomass.