Manley Amber, Collins Adrian L, Joynes Adrian, Mellander Per-Erik, Jordan Phil
Sustainable Agriculture Sciences, Rothamsted Research, North Wyke, Okehampton, EX20 2SB UK.
Agricultural Catchments Programme, Teagasc, Environment Research Centre, Johnstown Castle, Co., Wexford, Ireland.
Water Air Soil Pollut. 2020;231(10):524. doi: 10.1007/s11270-020-04871-w. Epub 2020 Oct 9.
Clean water is a precious resource, and policies/programmes are implemented worldwide to protect and/or improve water quality. Faecal pollution can be a key contributor to water quality decline causing eutrophication through nutrient enrichment and pathogenic contamination. The robust sourcing of faecal pollutants is important to be able to target the appropriate sector and to engage managers. Biomarker technology has the potential for source confirmation, by using, for example the biomarker suite of steroids. Steroids have been used in the differentiation of human and animal faeces; however, there is no unequivocal extraction technique. Some of the methods used include (i) Soxhlet extraction, (ii) Bligh and Dyer (BD) extraction, and (iii) accelerated solvent extraction (ASE). The less costly and time intensive technique of ASE is particularly attractive, but a current research gap concerns further comparisons regarding ASE lipid extraction from soils/slurries compared with the more traditional Soxhlet and BD extractions. Accordingly, a randomised complete block experiment was implemented to assess differences between the three extraction methods, differences between the different sample types, and the interactions between these two factors. Following GC-MS, it was found that there was no significant difference between the results of the steroid extraction methods, regardless of the type of sample used, for the quantity of each steroid extracted. It was concluded that ASE could be used confidently instead of the more established steroid extraction methods, thereby delivering time and cost savings.
清洁水是一种宝贵资源，世界各地都在实施相关政策/方案来保护和/或改善水质。粪便污染可能是导致水质下降的关键因素，通过营养物质富集和病原体污染造成富营养化。明确粪便污染物的来源对于确定合适的部门并促使管理人员采取行动至关重要。生物标志物技术有潜力通过使用例如类固醇生物标志物组合来确认污染源。类固醇已被用于区分人类和动物粪便；然而，目前尚无明确的提取技术。使用的一些方法包括：（i）索氏提取法，（ii）布莱和戴尔（BD）提取法，以及（iii）加速溶剂萃取法（ASE）。ASE成本较低且耗时较少，特别有吸引力，但目前的研究差距在于，与更传统的索氏提取法和BD提取法相比，还需要进一步比较从土壤/泥浆中进行ASE脂质提取的情况。因此，开展了一项随机完全区组试验，以评估三种提取方法之间的差异、不同样品类型之间的差异以及这两个因素之间的相互作用。经过气相色谱 - 质谱联用分析后发现，无论使用何种样品类型，对于每种提取的类固醇数量而言，类固醇提取方法的结果之间没有显著差异。得出的结论是，可以放心地使用ASE替代更成熟的类固醇提取方法，从而节省时间和成本。
