分析化学方法研究螺灭杀的水体降解动态  

Study of degradation dynamics of luomiecide in water by analytical chemistry method

作　　者：王晗[1] 徐世芳[1] 陈爱瑛[1] 朱明东[1] 姜丽霞[1] 

机构地区：[1]浙江省医学科学院,杭州310013

出　　处：《中国媒介生物学及控制杂志》2010年第5期445-447,共3页Chinese Journal of Vector Biology and Control

摘　　要：目的建立灵敏、准确的分析化学方法以替代生物测定方法,用以研究灭螺药"螺灭杀"(50%氯硝柳胺乙醇胺盐可湿性粉剂)在实验室及灭螺现场水体中的降解动态。方法高效液相色谱法(HPLC)∶C18柱,流动相为甲醇-0.01mol/L醋酸钠(87∶13),理论板数>3000;进样100μl,UV检测波长为330nm。实验室模拟降解:螺灭杀水溶液分装小瓶,置日光下,于10d内取样6次,分别用直接过滤和有机溶剂助溶的方法处理2组供试水样,测定;现场灭螺取样6次,水样处理及测定同上。结果 HPLC法最低检出浓度为0.007mg/L;线性范围为0.01～2.42mg/L(r=0.9999,n=12),主峰与杂质分离度>1.5。实验室模拟降解,前3天内原药含量迅速降低,第10天时测定结果比0d下降了83%,第7天测得浓度仅为最低有效浓度。而沉于瓶底的絮状物,经测定为氯硝柳胺。现场施药测得次日即低于有效浓度,估计与取样代表性难以保证有关。结论实验室研究揭示了该药在水体中灭螺效果随时间递减的现象与该制剂在水中逐渐解离为氯硝柳胺单体,并再次聚集为不溶性絮状物导致浓度下降有关,而非因氯硝柳胺化学降解所致。分析化学法不适合大水体现场监测。Objective To establish a sensitive and accurate analytical chemistry method as an alternative to biological tests for determination of degradation dynamics of a molluscicide, Luomiecide （50% wettable powder of niclosamide ethanolamine salt）, in laboratory and in water bodies. Methods High performance liquid chromatography （HPLC） was performed using a C18 column and a mobile phase of methanol-0.01 mol/L sodium acetate （87∶13） with the theoretical plate number 〉3000; a 100 μl, UV detection wavelength of 330 nm was chosen. Laboratory simulation of degradation was conducted, where vials of luomiecide solutions were placed in the sun for 6 times of sampling in 10 d; a parallel couple of samples were either directly filtered or solubilized with organic solvents, and measured. Another 6 samples were collected on the spot of molluscicidal application, treated and detected following the same procedures. Results The minimum detectable concentration by HPLC was 0.007 mg/L, the linear range 0.01-2.42 mg/L （r=0.9999, n=12） and the separation between main peaks and impurities 〉1.5. In laboratory simulation, the original drug concentration dropped rapidly within the first 3 d, with a decrease of 83% on day 10 compared with that on day 0, and the measured concentration on day 7 reduced to the minimum effective level. The bottoming flocculi were identified as niclosamide. As for on-site application, the measured concentration on day 2 was already lower than the minimum effective level, which might be due to the scarce representativeness of the used samples. Conclusion The laboratory study revealed that the decreasing molluscicidal effect of the agent in water with time was a result of the gradual degradation of the agent to niclosamide monomers in water, which again accumulated to form insoluble flocculi and led to concentration decrease, other than chemical degradation of niclosamide. Analytical chemistry methods were not applicable for on-site monitoring of large water bodies.

关 键 词：氯硝柳胺乙醇胺盐 氯硝柳胺 螺灭杀 高效液相色谱法 水体 降解 

分 类 号：S481.9[农业科学—农药学]