真空紫外活化亚硫酸盐在有氧条件下降解二甲双胍

Degradation of metformin by vacuum ultraviolet activated sulfite under aerobic conditions

以治疗Ⅱ型糖尿病的基础药物——二甲双胍(MET)为研究对象,考察其在真空紫外(VUV)活化亚硫酸盐有氧(VUV/SO_(3)^(2-)/O_(2))体系中的降解效果。通过淬灭试验,验证了反应体系中硫酸盐自由基(SO_(4)^(-)·)、羟基自由基(HO·)、水合电子(e-aq)和氢离子自由基(·H)活性物质的存在,同时考察VUV/SO_(3)^(2-)/O_(2)体系中pH、亚硫酸盐(SO_(3)^(2-))浓度、光强、天然有机物(NOM)和常见无机离子对MET降解的影响。结果表明VUV/SO_(3)^(2-)/O_(2)体系对MET的降解效果明显优于VUV/O_(2)或SO_(3)^(2-)/O_(2)体系,在180 min内可降解91%的MET;MET降解率随pH的增大先上升后下降,随SO_(3)^(2-)浓度和光强的增加而增加;NOM、HCO_(3)^(-)、Cl^(-)和NH+4的加入对MET降解均起到抑制作用。共检测到6种降解产物,推测MET共有3条降解路径,产物主要经过C—N键断裂、去甲基化、脱氨基化、环化和脱氢等反应得到。

Metformin(MET),the basic drug for the treatment of typeⅡdiabetes,was used as the research object to investigate the degradation effect in the vacuum ultraviolet(VUV)activated sulfite aerobic(VUV/SO_(3)^(2-)/O_(2))system.The existence of sulfate radical(SO_(4)^(-)·),hydroxyl radical(HO·),hydrated electron(e-aq)and hydrogen ion radical(·H)active substances in the reaction system was verified by quenching test.At the same time,the effects of pH,sulfite(SO_(3)^(2-))concentration,light intensity,natural organic matter(NOM)and common inorganic ions on the degradation of MET in VUV/SO_(3)^(2-)/O_(2)were investigated.The results showed that the degradation of MET by VUV/SO_(3)^(2-)/O_(2)system was significantly better than VUV/O_(2)or SO_(3)^(2-)/O_(2)system,and 91%of MET could be degraded within 180 min;With the increase of pH,the MET degradation rate increased first and then decreased.With the increase of SO_(3)^(2-)concentration and light intensity,the MET degradation rate increased.The MET addition of NOM,HCO_(3)^(-),Cl^(-)and NH+4 could inhibit the removal of MET by VUV/SO_(3)^(2-)/O_(2).A total of six substances were detected.It was speculated that there were three degradation paths of MET.The intermediate products were mainly obtained through C-N bond breaking,demethylation,deamination,cyclization and hydrogen extraction.