碳酸钙沉淀法检测混浊原水中“两虫”的研究

Detection of Cryptosporidium and Giardia in Turbid Source Water by Calcium Carbonate Precipitation Method

对于混浊水源水中"两虫"的检测,选定有效的浓缩富集及分离纯化方法尤为重要。滤囊/滤芯富集—免疫磁分离(IMS)组合方法对混浊水源水的预处理效果较好,但成本过高。为此,研究了碳酸钙沉淀法对某混浊河水中"两虫"的浓缩富集效果,并对浓缩后样品比较了密度梯度离心法和免疫磁分离法的分离纯化效果。结果发现,利用碳酸钙沉淀法可有效实现水中"两虫"的富集;从分离纯化效果来看,Percoll—蔗糖密度梯度离心方法对贾第鞭毛虫和隐孢子虫的平均回收率分别可达72.3%和39.5%,相对标准偏差分别为10.8%和11.9%;与国标方法中免疫磁分离方法的效果相当,但可显著降低分析成本。因此,碳酸钙沉淀—密度梯度离心组合技术用于混浊水源水中"两虫"的检测具有较好的应用前景。

For detection of Cryptosporidium and Giardia in turbid source water, it is important to select an efficient process for sample concentration and purification. A combined method of capsule/cartridge filters and immunomagnetic separation （IMS） is effective in pretreatment of turbid source water, but its cost is high. The concentration of Cryptosporidium and Giardia in a river water sample by calcium carbonate precipitation method was investigated. Two separation and purification methods, Percoll-sucrose density gradient centrifugation （PSDGC） and immunomagnetic separation （ IMS）, were compared for their separation efficiency. The results showed that the calcium carbonate precipitation method could effectively concentrate Cryptosporidium and Giardia. The average recovery rates of Cryptosporidium and Giardia by PSDGC were 72.3% and 39.5%, and the RSDs were 10.8% and 11.9%, respectively, showing that PSDGC had similar separation efficiency to IMS method, but with a lower cost. So the cornbination of calcium carbonate precipitation and PSDGC could be used for detection of Cryptosporidium and Giardia in turbid source water.