Real-time detection of faecally contaminated drinking water with tryptophan-like fluorescence: defining threshold values
Real-time detection of faecally contaminated drinking water with tryptophan-like fluorescence: defining threshold values
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DOI：
10.1016/j.scitotenv.2017.11.162
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发表时间：
2018-05-01
影响因子：
9.8
通讯作者：
Ward, Jade S. T.
中科院分区：
文献类型：
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作者：
Sorensen, James P. R.;Baker, Andy;Ward, Jade S. T.
我们评估了使用激发发射波长为 280 nm 和 360 nm 的荧光溶解有机物（称为类色氨酸荧光 (TLF)）作为粪便污染饮用水的指标。使用来自印度、马拉维、南非和赞比亚的地下水和地表水饮用水源的数据，使用 TLF 作为耐热大肠菌群 (TTC) 的预测因子，开发了一个显着的逻辑回归模型。选择 1.3 ppb 溶解色氨酸的 TLF 阈值对 TTC 污染进行分类。 TLF 阈值的验证表明假阴性错误率为 15%，假阳性错误率为 18%。该阈值无法成功对每 100 mL 含有 < 10 TTC cfu 的污染源进行分类，我们认为这是当前的检测极限。如果仅对高于此限制的源进行分类，假阴性错误率非常低，为 4%。 TLF 强度与 TTC 浓度密切相关 (rho(s) = 0.80)。建议采用 6.9 ppb 溶解色氨酸的较高阈值来指示严重污染源（= 每 100 mL 100 TTC cfu）。目前市售的荧光计易于使用，适合在线和远程环境使用，既不需要试剂也不需要消耗品，并且最重要的是提供即时读数。在典型的自然范围内，TLF 测量不会明显受到常见干扰因素（例如 pH、浊度和温度）的影响。该技术是实时筛查全球受粪便污染的饮用水的可行选择。 (C) 2017 年自然环境研究委员会 (NERC)，以英国地质调查局 (BGS) 为代表。由 Elsevier B.V. 出版。保留所有权利。
We assess the use of fluorescent dissolved organic matter at excitation-emission wavelengths of 280 nm and 360 nm, termed tryptophan-like fluorescence (TLF), as an indicator of faecally contaminated drinking water. A significant logistic regression model was developed using TLF as a predictor of thermotolerant coliforms (TTCs) using data from groundwater- and surface water-derived drinking water sources in India, Malawi, South Africa and Zambia. A TLF threshold of 1.3 ppb dissolved tryptophan was selected to classify TTC contamination. Validation of the TLF threshold indicated a false-negative error rate of 15% and a false-positive error rate of 18%. The threshold was unsuccessful at classifying contaminated sources containing < 10 TTC cfu per 100 mL, which we consider the current limit of detection. If only sources above this limit were classified, the false-negative error rate was very low at 4%. TLF intensity was very strongly correlated with TTC concentration (rho(s) = 0.80). A higher threshold of 6.9 ppb dissolved tryptophan is proposed to indicate heavily contaminated sources (= 100 TTC cfu per 100 mL). Current commercially available fluorimeters are easy-to-use, suitable for use online and in remote environments, require neither reagents nor consumables, and crucially provide an instantaneous reading. TLF measurements are not appreciably impaired by common intereferents, such as pH, turbidity and temperature, within typical natural ranges. The technology is a viable option for the real-time screening of faecally contaminated drinking water globally. (C) 2017 Natural Environment Research Council (NERC), as represented by the British Geological Survey (BGS). Published by Elsevier B.V. All rights reserved.