Schumacher Melanie, Castle Glenn, Gravell Anthony, Mills Graham A, Fones Gary R
Natural Resources Wales, Llanelli Laboratory, 19 Penyfai Lane, Llanelli SA15 4EL, UK.
School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, UK.
MethodsX. 2016 Mar 10;3:188-94. doi: 10.1016/j.mex.2016.03.004. eCollection 2016.
The molluscicide metaldehyde (2,4,6,8-tetramethyl-1,3,5,7-tetraoxocanemetacetaldehyde) is an emerging pollutant. It is frequently detected in surface waters, often above the European Community Drinking Water Directive limit of 0.1 μg/L for a single pesticide. Gas chromatography mass spectrometry (GC-MS) can be used to determine metaldehyde in environmental waters, but this method requires time consuming extraction techniques prior to instrumental analysis. Use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) can overcome this problem. We describe a novel LC-MS/MS method, using a methylamine mobile phase additive, coupled with on-line sample enrichment that allows for the rapid and sensitive measurement of metaldehyde in surface water. Only the methylamine adduct of metaldehyde was formed with other unwanted alkali metal adducts and dimers being suppressed. As considerably less collision energy is required to fragment the methylamine adduct, a five-fold improvement in method sensitivity, compared to a previous method using an ammonium acetate buffer mobile phase was achieved. This new approach offers: •A validated method that meets regulatory requirements for the determination of metaldehyde in surface water.•Improved reliability of quantification over existing LC-MS/MS methods by using stable precursor ions for multiple reaction monitoring.•Low limits of quantification for tap water (4 ng/L) and river water (20 ng/L) using only 800 μL of sample; recoveries > 97%.
杀软体动物剂聚乙醛（2,4,6,8 - 四甲基 - 1,3,5,7 - 四氧杂环辛烷四甲醛）是一种新兴污染物。它在地表水中经常被检测到，其含量常常超过欧盟饮用水指令中单一农药0.1μg/L的限值。气相色谱 - 质谱联用（GC - MS）可用于测定环境水体中的聚乙醛，但该方法在仪器分析之前需要耗时的萃取技术。使用液相色谱 - 串联质谱（LC - MS/MS）可以克服这一问题。我们描述了一种新颖的LC - MS/MS方法，该方法使用甲胺作为流动相添加剂，并结合在线样品富集技术，能够快速且灵敏地测定地表水中的聚乙醛。仅形成了聚乙醛的甲胺加合物，其他不需要的碱金属加合物和二聚体受到抑制。由于裂解甲胺加合物所需的碰撞能量大大降低，与先前使用乙酸铵缓冲液流动相的方法相比，方法灵敏度提高了五倍。这种新方法具有以下优点：•一种经过验证的方法，满足地表水中聚乙醛测定的监管要求。•通过使用稳定的前体离子进行多反应监测，比现有LC - MS/MS方法提高了定量的可靠性。•仅使用800μL样品，自来水（4 ng/L）和河水（20 ng/L）的定量下限低；回收率> 97%。
