加工对蜂蜜中两种有机磷类农药含量的影响及大孔树脂吸附脱除研究

【作者】 朱青；

【导师】 曹炜；

【作者基本信息】 西北大学 ， 食品科学， 2010， 硕士

【摘要】 本课题研究了蜂蜜中的两种残留农药—毒死蜱和马拉硫磷在加工过程中的含量变化,并使用大孔树脂吸附的方法对蜂蜜中的马拉硫磷和氯霉素进行了脱除研究。全文共分为四章,作者的主要工作为以下三个方面：1、研究了毒死蜱和马拉硫磷在蜂蜜加工过程中的含量变化。结果表明蜂蜜加工对这两种有机磷类农药的含量有较大影响,毒死蜱和马拉硫磷的含量分别降低了70%和22.5%。其中真空浓缩步骤的影响最大,两种农药含量分别下降了60.9%和16.5%,过滤的影响次之。2、对蜂蜜中的马拉硫磷在大孔吸附树脂上的吸附行为进行了热力学研究。结果表明：在298K、308K和318K的浓度范围内,LS-903型大孔树脂对蜂蜜中马拉硫磷的平衡吸附数据较好地符合Freundlich吸附等温方程；蜂蜜中的马拉硫磷在LS-903型大孔树脂上的吸附焓变小于零,表明此吸附过程是一个放热过程,低温有利于吸附的进行；LS-903型大孔树脂对马拉硫磷的吸附自由能变为负,表明树脂对马拉硫磷的吸附具有较强的驱动力,吸附为自发反应。3、对蜂蜜中的氯霉素在大孔树脂上的吸附行为进行了动力学研究。讨论了温度、吸附时间和搅拌速度等因素对吸附过程的影响。结果表明,LS-903型大孔树脂对蜂蜜中氯霉素的吸附速率较好的符合了拟二级动力学方程,其拟合的动力学参数k2=0.006,qe=17.48μg／g；氯霉素在LS-903树脂上的吸附过程的控制步骤为膜扩散和粒扩散过程,其扩散系数分别为0.0015和0.0010。更多还原

【Abstract】 The effects of different steps in honey production on chlorpyrifos and malathion levels are investigated. The removal effect of malathion and chloramphenicol in honey on the macroporous adsorption resin are also studied. The content of this article consisted of four chapters, and the author’s work are in the following three aspects.1. Chlorpyrifos and malathion residues in honey are quantified by gas chromatography with flame photometric detection (GC-FPD) after each stage including preheating, filtration, vacuum concentration and pasteurization. The total loss of chlorpyrifos and malathion in honey are about 70% and 22.5%, respectively. Among these four stages, vacuum concentration had the significant effects on chlorpyrifos and malathion levels, and the mean losses were 60.9 and 16.5%, respectively. Filtration had the secondary reduction effect.2. Thermodynamic properties of adsorption of malathion in honey by macroporous adsorption resins (LS-903) were investigated using static adsorption method. Equilibrium data were obtained from the adsorption of malathion in honey at 298K,308K and 318K, respectively and correlated with Freundlich-type of isotherm equation. Freundlich adsorption isotherms and isosteric enthalpy of adsorption indicate that the process of adsorption of malathion by LS-903 resin is an exothermic process. The negative value of△G indicates the spontaneous nature of the adsorption process.3. Adsorptive kinetics of chloramphenicol in honey by macroporous adsorption resions (LS-903) were investigated. The effects of temperature, time and agitation on the adsorption have been investigated. The speeds of adsorption appear to follow pseudo-second-order kinetics model. The adsorption was controlled by pore diffusion and film diffusion. The diffusion coefficients (D) calculated by using Fick’s equation were 0.0015 and 0.0010.更多还原