TY - JOUR
T1 - Solid-phase extraction coupled with electrochemical detection for the determination of the herbicide bromofenoxim in water samples at low- and sub-μg l-1 levels
AU - Svegl, I. G.
AU - Ogorevc, B.
AU - Novic, M.
AU - Benfenati, E.
PY - 1996
Y1 - 1996
N2 - The application of solid-phase extraction (SPE) as a preconcentration and clean-up step with subsequent off-line flow injection amperometric (FI-AD) or batch square-wave voltammetric (SWV) detection of the herbicide bromofenoxim was developed. The selection of an appropriate organic eluent, some parameters influencing the efficiency of the SPE and the electrochemical detection of bromofenoxim in the organic effluent solution were thoroughly investigated. Undiluted acetonitrile with SWV and acetonitrile-water (80 + 20) with FI-AD, both containing 0.1 mol l-1 LiClO4, were chosen as the most appropriate SPE eluents. The addition of LiClO4 as supporting electrolyte to the eluent and acidification of a water sample to 1 x 10-3 mol l-1 HClO4 (pH 3) prior to the SPE procedure were found to improve greatly the current response on mercury drop (SWV) and mercury film (FI-AD) electrodes. Subsequent to the SPE procedure, the effluents were transferred to the voltammetric cell or injected into the flow injection system without any further treatment. The calibration plots obtained for bromofenoxim in pure water samples were linear over the ranges 0.2-12.0 μg l-1 and 3.0-120 μg l-1, with calculated detection limits of 0.05 and 1.5 μg l-1 (100 ml samples), for the SPE-SWV and SPE-FI-AD procedures, respectively. The actual detection capabilities of the proposed methods depend on the water sample volumes applied to the extraction cartridges. The recoveries of the over-all procedures, applying spiked tap water samples, and the corresponding RSDs were 92% and 6% (n = 6) and 121% and 9% (n = 7) for SPE-SWV and SPE-FI-AD, respectively. The practical applicability of the proposed methods for the analysis of ground and tap water samples was confirmed via an inter-laboratory test on a tap water sample containing five common pesticides including bromofenoxim.
AB - The application of solid-phase extraction (SPE) as a preconcentration and clean-up step with subsequent off-line flow injection amperometric (FI-AD) or batch square-wave voltammetric (SWV) detection of the herbicide bromofenoxim was developed. The selection of an appropriate organic eluent, some parameters influencing the efficiency of the SPE and the electrochemical detection of bromofenoxim in the organic effluent solution were thoroughly investigated. Undiluted acetonitrile with SWV and acetonitrile-water (80 + 20) with FI-AD, both containing 0.1 mol l-1 LiClO4, were chosen as the most appropriate SPE eluents. The addition of LiClO4 as supporting electrolyte to the eluent and acidification of a water sample to 1 x 10-3 mol l-1 HClO4 (pH 3) prior to the SPE procedure were found to improve greatly the current response on mercury drop (SWV) and mercury film (FI-AD) electrodes. Subsequent to the SPE procedure, the effluents were transferred to the voltammetric cell or injected into the flow injection system without any further treatment. The calibration plots obtained for bromofenoxim in pure water samples were linear over the ranges 0.2-12.0 μg l-1 and 3.0-120 μg l-1, with calculated detection limits of 0.05 and 1.5 μg l-1 (100 ml samples), for the SPE-SWV and SPE-FI-AD procedures, respectively. The actual detection capabilities of the proposed methods depend on the water sample volumes applied to the extraction cartridges. The recoveries of the over-all procedures, applying spiked tap water samples, and the corresponding RSDs were 92% and 6% (n = 6) and 121% and 9% (n = 7) for SPE-SWV and SPE-FI-AD, respectively. The practical applicability of the proposed methods for the analysis of ground and tap water samples was confirmed via an inter-laboratory test on a tap water sample containing five common pesticides including bromofenoxim.
KW - Bromofenoxim
KW - Electrochemical detection
KW - Flow injection
KW - Herbicides
KW - Solid-phase extraction
KW - Water analysis
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U2 - 10.1039/an9962101839
DO - 10.1039/an9962101839
M3 - Article
C2 - 9008406
AN - SCOPUS:0030453235
VL - 121
SP - 1839
EP - 1843
JO - The Analyst
JF - The Analyst
SN - 0003-2654
IS - 12
ER -