食品中常见有机物还原Cr(Ⅵ)反应动力学Reduction Kinetics of Cr(Ⅵ) in the Presence of Common Food Organics
梅喜艳,祝巨,傅杰,姜仁禹,张淹,郭尚伟,尤金花,吕秀阳
摘要(Abstract):
采用二苯碳酰二肼分光光度法,测定了食品中15种常见有机物在不同pH值、不同温度下还原Cr(Ⅵ)的动力学数据,结果表明:L-抗坏血酸、L-半胱氨酸盐酸盐、L-甲硫氨酸表现出较强的还原Cr(Ⅵ)能力,其余12种有机物在5 h内基本未还原Cr(Ⅵ)。L-抗坏血酸在短时可将Cr(Ⅵ)全部还原,L-半胱氨酸盐酸盐在60 min内可将Cr(Ⅵ)全部还原,L-甲硫氨酸在5 h内能将Cr(Ⅵ)还原23%,其还原能力次序为:L-抗坏血酸>L-半胱氨酸盐酸盐>L-甲硫氨酸。pH值对还原反应动力学影响较大,L-半胱氨酸盐酸盐对Cr(Ⅵ)的还原作用随pH的升高而增强,而L-甲硫氨酸对Cr(Ⅵ)的还原作用则随pH的升高而减弱直至不反应。以零级反应动力学方程拟合了pH=3.0时L-甲硫氨酸还原Cr(Ⅵ)的动力学数据,得到L-甲硫氨酸还原Cr(Ⅵ)的表观活化能为35.5 kJ mol 1;以一级反应动力学方程拟合了L-半胱氨酸盐酸盐还原Cr(Ⅵ)动力学数据,得到pH=3.0、5.0和7.0时,L-半胱氨酸盐酸盐还原Cr(Ⅵ)的表观活化能分别为34.4,45.3,34.9kJ mol 1。
关键词(KeyWords): 有机物;Cr(Ⅵ);还原反应;动力学
基金项目(Foundation): “重大新药创制”科技重大专项“中药大品种阿胶技术改造”(2011ZX09201-201-10)资助项目
作者(Author): 梅喜艳,祝巨,傅杰,姜仁禹,张淹,郭尚伟,尤金花,吕秀阳
参考文献(References):
- [1]LIANG Qi-feng(梁奇峰).Chromium and human health(铬与人体健康)[J].Guangdong Trace Elements Science(广东微量元素科学),2006,13(2):67-69.
- [2]SUN Gen-xing(孙根行),YU Cong-zheng(俞从正).Development of the research of hexavalent chromium in leather(皮革中六价铬的研究进展)[J].China Leather(中国皮革),2002,31(7):35-39.
- [3]WANG Li-jun(王立军),ZHANG Shen(章申).Morphological transformation of Cr(III)and Cr(VI)in the medium of soil with water(土壤水介质中Cr(Ⅲ)与Cr(Ⅵ)形态的转化)[J].Environmental Science(环境科学),1982,3(4):38-42.
- [4]Wittbrodt P R,Palmer C D.Reduction of Cr(Ⅵ)in thepresence of excess soil fulvic acid[J].Environmental Science&Technology,1995,29(1):255-263.
- [5]LIANG Bin(梁斌),LAN Jie(兰洁),LAN Ye-qing(兰叶青).Comparison of the reduction of Cr(VI)by mandelic,malic and lactic acids(苦杏仁酸、苹果酸、乳酸对Cr(Ⅵ)还原作用的比较)[J].Acta Scientiae Circumstantiae(环境科学学报),2007,27(8):1326-1330.
- [6]TIAN Xiao-fang(田晓芳),GAO Xian-chao(高显超),GUO Jing(国静),et al.Catalytic role of Mn(Ⅱ)and Fe(Ⅲ)in the reduction of Cr(VI)by oxalic acid(过渡金属离子Mn(Ⅱ)和Fe(Ⅲ)对草酸还原Cr(VI)的催化作用)[J].Journal of Nanjing Agricultural University(南京农业大学学报),2009,32(4):160-164.
- [7]LEI Xue-fei(雷雪飞),XUE Xiang-xin(薛向欣).Effect of acidity and acidic medium on photocatalytic reduction of Cr(VI)by sulfate modified titanium-bearing blast furnace slag(酸度及酸介质对硫酸盐掺杂的含钛高炉渣光催化还原Cr(VI)的影响)[J].J Chem Indand Eng(China)(化工学报),2008,59(9):2247-2254.
- [8]LIU Yong(刘永),XU Xin-hua(徐新华),JIANG Dong(江栋).Research on affecting factors of Cr(VI)degradation by L-ascorbic acid(L-抗坏血酸还原降解六价铬的影响因素)[J].Research of Environmental Sciences(环境科学研究),2008,21(4):25-28.
- [9]LI Jing(李静),WANG Yu(王雨),CHEN Hua-bao(陈华宝),et al.Simultaneous extraction and determination of chromium(III)and chromium(VI)in milk(牛奶中三价铬和六价铬的同时提取和检测方法)[J].Food Science(食品科学),2010,31(10):250-253.
- [10]TANG Xin-hu(汤心虎),WEI Chao-hai(韦朝海),LONG Bao-gen(龙宝根),et al.Photocatalytic reduction of hexavalent chromium in its low concentration solution(稀水溶液中Cr(VI)的光催化还原研究)[J].Environment Chemistry(环境化学),2006,25(1):20-23.
- [11]Department of Physical Chemistry,Tianjin University(天津大学物理化学教研室).Physical ChemistryⅡ(物理化学下册)[M].Beijing(北京):Higher Education Press(商业教育出版社).2001:27-46.
- [12]LIU Zi-li(刘自力),LIU Hong-wei(刘宏伟),LI Ru(李茹).Photocatalytic reduction of wastewater containing Cr(VI)by photocatalyst Cu2O(Cu2O光催化还原含铬(VI)废水的研究)[J].J Chem Eng of Chinese Univ(高校化学工程学报),2007,21(1):88-92.
- [13]LIU Shi-hong(刘世宏),ZHAO Liang-zhong(赵良仲),WANG Dang-han(王当憨).Study of the oxidation mechanism of disulfide bonds,sulfhydryl groups and melanin in human epidermal skin by X-ray photoelectron spectroscopy(用X光电子能谱研究人体表皮中二硫键、巯基和黑色素的氧化机理)[J].Acta Chimica Sinica(化学学报),1983,41(8):716-721.