生活饮用水中细菌总数检测的方法比较与应用

Comparison and Application of Methods for Detecting Total Bacteria in Drinking Water

自《生活饮用水卫生标准》(GB 5749—2006)实施以来,市场上涌现出各种针对生活饮用水样品的细菌总数检测方法。文中选取了检测中常见的营养琼脂异养菌平板计数(HPC)检测方法、R2A HPC检测方法、复合酶底物检测方法和ATP生物荧光检测方法,分别对标准物质样品和上海浦东某水厂样品进行了对比检测。结果表明,除ATP生物荧光法外,其余3种方法的检测结果均在标准物质样品真值的3倍标准偏差可接受范围内。培养法中HPC涂布检测方法对生活饮用水中微生物指标的检测灵敏性更高,但检测周期较长、人员和环境要求严格,在实际市场应用时需根据检测需求配套使用其他检测方法。而ATP生物荧光检测方法检测效率很高,平均单个样品检测时间为5 min,操作简单、环境要求较低,结果可以间接反映水中微生物含量,适用于时效性要求较高的检测任务。酶底物法可用于移动实验室等无法很好保证环境在无菌情况下的检测场景。

Since the implementation of Standards for Drinking Water Quality(GB 5749—2006),various total bacteria testing methods for drinking water samples have emerged on market.This article selected common nutrient agar heterotrophic plate count( HPC)detection method,R2A HPC detection method,enzyme substrate technique and ATP biofluorescence detection method that were common in detection market.It was compared with a sample from a water plant in Pudong,Shanghai.Results showed that,except for ATP biofluorescence method,detection results of other three methods were all within the acceptable range of 3 times the standard deviation of the true value of standard material sample.In the culture method,HPC coating detection method was more sensitive to the detection of microbial indicators in drinking water,but it had a long detection cycle and strict personnel and environmental requirements.In actual market applications,other detection methods must be used according to detection requirements.ATP biofluorescence detection method had a high detection efficiency.Average detection time for a single sample was 5 minutes.It was easy to operate and environmental requirements were low.Results can indirectly reflect microbial content in water,which was suitable for detection tasks with high timeliness requirements.Enzyme substrate technique can be used for testing tasks in mobile laboratories where the sterility of environment cannot be guaranteed.