Analytical Method for Determination of Some Priority Substances in Surface and Ground Water Samples by Liquid Chromatography – Mass Spectrometry

Abstract

Chemical status of water bodies is determined through environmental quality standards, defined for priority pollutants (Directive 2008/105/EC, Off J Eur Commun, December 24, L 348/84, 2008), mostly represented by persistent organic compounds and pesticides. There is a need for precise and accurate analytical methods for reliable assessment of environmental status of surface and ground waters. The aim of this work was to develop an innovative multiresidue analytical method for simultaneous determination of some priority substances in surface and ground waters. Determined target compounds include the pesticides: Acetochlor, Alachlor, Chlorfenvinphos, Chlorpyrifos, Diuron, Isoproturon, Pendimethalin and Trifluralin. Analytical approach was based on a solid-phase extraction (SPE) as a sample pretreatment procedure and a liquid chromatography–mass spectrometry (LC–MS) as an instrumental method. Optimal chemical conditions for quantitative separation and preconcentration of the analytes in a single step extraction procedure are defined. LC–MS method performance is discussed in details. The achieved analytical recovery for all compounds was greater than 86 % and repeatability is up to 10 %. The established detection limits were ranged between 1 and 10 ng/L and the quantification limits were between 5 and 50 ng/L, respectively. The concentration levels of measured priority substances in main Bulgarian rivers were presented.