摘要
以甲壳素为原料制备乳糖化壳聚糖,研究不同脱乙酰度的乳糖化壳聚糖对重金属离子Cr6+、Pb2+吸附能力及其机制。研究表明,乳糖化壳聚糖脱乙酰度随Na OH浓度的增加而增加,在Na OH饱和溶液中达到最大;不同脱乙酰度的乳糖化壳聚糖对Cr6+的清除率随乳糖化壳聚糖脱乙酰度的增加呈先不变后降低的趋势,最大清除率为47.26%;而对Pb2+的清除率随乳糖化壳聚糖脱乙酰度的增加先升高后降低,在乳糖化壳聚糖脱乙酰度为56.4时达到最大,最大清除率可达62.09%。红外扫描显示,乳糖壳聚糖主要是-OH和-NH参与重金属吸附反应,吸附Cr6+时O=C=O参与配位,吸附Pb2+时-NO3参与配位;电镜扫描结果显示,乳糖化壳聚糖具有较好的三维结构,对Cr6+、Pb2+的吸附除配位结合外,也有部分附着在其三维结构中。因此,乳糖化壳聚糖对重金属离子具有一定的清除能力,其吸附形式主要为配位键吸附和结构吸附2种形式。
Actosaminated chitosans with different degrees of deacelation（DD） were prepared from chitin and their application in the absorption of Cr6＋ and Pb2＋ and the involved mechanism were studied in this paper. It was found that the DD of actosaminated chitosan increased along with the elevation of Na OH concentration and maximized in saturated Na OH solution. The clearance rate of the derivatives towards Cr6＋ remained unchanged in a certain DD range, but then decreased as the DD further increased and the highest absorption capacity was 47.26%. As for Pb2＋ absorption, the clearance rate of actosaminated chitosans increased along with DD elevation in a certain range and then decreased and the highest clearance rate was as high as 62.09%. FTIR revealed that the absorption capacity was mainly contributed by the –OH and –NH groups. The O=C=O groups was involved in the coordination with Cr6＋ and the –NO3 groups participated in the coordination with Pb2＋. SEM indicated that the actosaminated chitosan possessed good three-dimensional structure and partial absorbed Cr6＋ and Pb2＋ were attached to the structure in addition those absorbed through coordination. It was concluded that actosaminated chitosan exhibited clearance capacity towards heavy metals and coordination and structural absorption were mainly responsible for the absorption.
出处
《食品科技》
CAS
北大核心
2015年第5期269-273,共5页
Food Science and Technology
基金
国家"十二五"科技支撑项目(2012BAK17B05
2012BAD28B03
2012BAD39B05
2012BAK26B003)
