Solid-phase extraction and photo-induced fluorescence detection of metsulfuron methyl in flow-batch system

CAROLINA C. ACEBAL; MARCOS GRUNHUT; IVANA SRÁMKOVÁ; PETR CHOCHOLOUS; HANA SKLENÁROVÁ; ADRIANA G. LISTA; BEATRIZ S. FERNÁNDEZ BAND

Porto

Conferencia; 18th International Conference on Flow Injection Analysis; 2013

Sociedad Portuguesa de Química (SPQ); Japanese Association for Flow Injection Analysis (JAFIA)

Metsulfuron-methyl (MSM) is one of the most employed herbicides in Bahía Blanca's agricultural region. Although MSM is a naturally non-fluorescent compound, fluorescence signals can be obtained upon UV irradiation [1]. Since detection at low concentration levels is necessary, a preconcentration procedure is required. Flow-Batch Analysis (FBA) systems draw upon the useful features of batch and multi-commutation approaches [2]. In this work, a new FBA system with on-line solid-phase preconcentration step (C18; 100 mg; 60-80 µm particles) and photochemical induced fluorescence (PIF) detection (pH 12-13; irradiation time, 10 s) for determination of ppb levels of MSM was developed. The physical and chemical variables of the SPE-PIF-FBA system were exhaustively studied (eluting solvent, volume and flow rates of sample and eluting solvent, irradiation time, pH conditions, instrumental conditions). Both procedures should be harmonized in order to perform the correct formation of the photoproduct.