This paper describes an analytical method using high-performance liquid chromatographic (HPLC) separationcoupled with electrochemical detection to detect three dyes, Solvent Blue 14 (SB-14), Solvent Blue 35 (SB-35) andSolvent Red 24 (SR-24). The dyes were eluted and separated using a reversed-phase column (C-8) under isocraticelution with the mobile phase containing a mixture of acetonitrile/ammonium acetate (5.0 mmol L1) at the ratio of75: 25 (v/v). Two sample pretreatment methods were tested and successfully applied to quantify SB14, SB-35 and SR-24 dyes in gasoline samples. The proposed method was simple, fast and suitable to detect and quantify marker dyes ingasoline sample at low concentration.São Paulo State Univ UNESP, Dept Analyt Chem, Inst Chem, BR-14800900 Araraquara, SP, BrazilUniv Regensburg, Inst Analyt Chem Chemo & Biosensors, D-93040 Regensburg, GermanySão Paulo State Univ UNESP, Dept Analyt Chem, Inst Chem, BR-14800900 Araraquara, SP, Brazil