Thiago Faria Tormin

Publications (2)6.67 Total impact

• Article: Fast and direct determination of butylated hydroxyanisole in biodiesel by batch injection analysis with amperometric detection.

  Thiago Faria Tormin, Denise Tofanello Gimenes, Eduardo Mathias Richter, Rodrigo Alejandro Abarza Munoz
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  ABSTRACT: We report here, for the first time, application of batch injection analysis (BIA) with amperometric detection for determination of the phenolic antioxidant butylated hydroxyanisole (BHA) in biodiesel. A sample plug was directly injected onto a boron-doped diamond electrode immersed in 50% v/v hydroethanolic solution with 0.1 mol L(-1) HClO(4) using an electronic micropipette. Importantly, the only preparation step required for biodiesel analysis is dilution in the same hydroethanolic electrolyte solution. Our proposed method has several advantages for routine biodiesel analysis, including: a low relative standard deviation between injections (0.29%, n=20), high analytical frequency (120 h(-1)), adequate recovery values (93-101%) for spiked samples, satisfactory accuracy (based on comparative determinations by high-performance liquid-chromatography), and a low detection limit (100 ng of BHA per g of biodiesel). Finally, our method can be adapted for the determination of other antioxidants in biodiesel samples.
  Talanta 09/2011; 85(3):1274-8. · 3.79 Impact Factor
• Article: Flow‐Injection Amperometric Method for Indirect Determination of Dopamine in the Presence of a Large Excess of Ascorbic Acid

  Denise Tofanello Gimenes, Wallans Torres Pio dos Santos, Thiago Faria Tormin, Rodrigo Alejandro Abarza Munoz, Eduardo Mathias Richter
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  ABSTRACT: A simple flow injection amperometric system for fast and indirect quantification of dopamine (DA) in the presence of a large excess of ascorbic acid (AA) is reported. The method consists of the application of three sequential potential pulses to an unmodified glassy carbon-working electrode positioned in a wall-jet cell. DA is indirectly detected at +0.35 V through the reduction of the oxidation product (o-dopaminoquinone) electrochemically generated at +0.80 V. The third potential pulse (0.00 V) is applied for the regeneration (cleaning) of the unmodified working electrode. The limits of detection (LOD) and quantification (LOQ) were calculated as 50 and 170 nmol L−1, respectively. Considering the LOQ value, the present methodology allows DA quantification in the presence up to 5000-fold more of AA (1.0 mmol L−1).
  Electroanalysis 11/2009; 22(1):74 - 78. · 2.87 Impact Factor