Barroso MF, Nunes OC, Vaz MC, Delerue-Matos C. Square-wave voltametric method for determination of molinate concentration in a biological process using a hanging mercury drop electrode.
Anal Bioanal Chem 2005;
381:879-83. [PMID:
15690181 DOI:
10.1007/s00216-004-2971-9]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 11/08/2004] [Accepted: 11/17/2004] [Indexed: 11/24/2022]
Abstract
A square-wave voltammetric (SWV) method using a hanging mercury drop electrode (HMDE) has been developed for determination of the herbicide molinate in a biodegradation process. The method is based on controlled adsorptive accumulation of molinate for 10 s at a potential of -0.8 V versus AgCl/Ag. An anodic peak, due to oxidation of the adsorbed pesticide, was observed in the cyclic voltammogram at ca. -0.320 V versus AgCl/Ag; a very small cathodic peak was also detected. The SWV calibration plot was established to be linear in the range 5.0 x 10(-6) to 9.0 x 10(-6) mol L(-1); this corresponded to a detection limit of 3.5 x 10(-8) mol L(-1). This electroanalytical method was used to monitor the decrease of molinate concentration in river waters along a biodegradation process using a bacterial mixed culture. The results achieved with this voltammetric method were compared with those obtained by use of a chromatographic method (HPLC-UV) and no significant statistical differences were observed.
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