Development of Sustained-Release Container and High-performance Adsorbent of Pesticide Using Chitosan

以甲壳素的水解物壳聚糖作为甲壳类、昆虫壳和植物细胞壁的基本成分，用不同的交联剂戊二醛和环氧氯丙烷制备了两种壳聚糖微粒(CMS)和膜以及与Ag(I)和部分铂族金属离子(SCM)络合的CMS。利用这些微粒和膜研究了典型农药甲基对硫磷(MP)的吸附和释放行为。结果如下：(1)利用壳聚糖膜和DOLSA-壳聚糖杂化膜，研究了抗肿瘤药物铂族金属的渗透和缓释机理。(2)从CMS和SCMS对银(I)和MP的吸附的pH和浓度依赖关系来看，环氧氯丙烷交联的CM明显优于戊二醛交联的CM，但从pH和浓度的关系来看，环氧氯丙烷交联的CM明显优于戊二醛交联的CM。(3)甲基对硫磷自组装的自组装膜在低pH的冰醋酸和乙酸钠水溶液以及含有一定络合剂的缓冲溶液中也观察到了MP的释放行为。实验结果表明，含硫氰化铵(NH_4SCN)和氨(NH_40H)的水溶液可用于MP包埋SCM中MP的释放。(4)考察了NiP在柱填充SCM上的吸附和洗脱行为，阐明了水溶液pH值、NIP浓度和Ag(I)负载量对SCM上MP的最大负载量和吸附及洗脱速率的影响。

Using Chitosan being a hydrolyzed derivative of chitin distributed in nature as a fundamental component of shells of crustaceans and insects and plant cell walls, we prepared two types of chitosan microparticles (CMs)and membranes and CMs complexed with Ag(I) and some platinum group metal ion (SCMs) using different crosslinking agents, i.e., glutaraldehyde and epichlorohydrin. Using these microparticles and membranes we ave investigated and compared the absorption and release behavior of a typical pesticide, methyl parathion (MP).The obtained results are as follows :(1) Using chitosan membrane and DOLSA-chitosan hybrid membranes, we investigated the permeation and sustained-release mechanism of platinum group metal which is the anti-tumor drug.(2) From the pH and concentration dependencies of Ag (I) and MP adsorption onto both the CMs and SCMs, the epichlorohydrin-crosslinked CM apparently showed the superiority of Ag (I) adsorption over the glutaraldehyde-crosslinked CM, nevertheless, adsorption behavior of NIP onto SCM derived from each CM were observed in reverse.(3) Release behavior of MP from the methyl parathion-loaded SCMs were also observed by aqueous buffer solutions of acetic acid and sodium acetate of low pH as well as by that containing some complexing reagents. The results suggested that the aqueous solutions containing ammonium thiocyanide (NH_4SCN) and ammonia (NH_40H) could be applied for MP release from the MP-loaded SCMs without the silver leackage from the particles.(4) We investigated the adsorption and elusion behaviors of NIP through the column packed SCMs, to elucidate the influences of pH of aqueous solution, NIP concentration and loading amount of Ag (I) on SCMs on maximal loading amount and adsorption and elusion rates of MP We have found that SCM crosslinked by glutaraldehyde has high durability of repeating column operation with reversible adsorption and elusion of MP.