Based on the study of voltammetric behavior of carcinogenic 1-nitropyrene (1-NP), 1-aminopyrene (1-AP), and 1-hydroxypyrene (1-HP), optimum conditions have been found for the determination of these analytes by differential pulse voltammetry (DPV) at a boron-doped diamond film electrode. The optimum medium was methanol-Britton-Robinson buffer (BR buffer) pH 3.0 (70:30) for 1-NP and 1-AP, and methanol-BR buffer pH 5.0 (70: 30) for 1-HP.
Concentration dependences of the DPV response were measured in the range 1.10(-6)-1.10(-4) mol dm(-3) (R= -0.9998) with the limit of detection (LOD) 3.10(-7) mol dm(-3) for 1-NP, 1.10(-7)-1.10(-5) mol dm(-3) (R = 0.9971) with LOD 6.10(-8) mol dm(-3) for 1-AP, and 1.10(-7)-1.10(-5) mol dm(-3) (R = 0.9934) with LOD 1.10(-7) mol dm(-3) for 1-HP. Simultaneous determination of 1-NP and 1-AP in a mixture was tested in the methanol-BR buffer pH 3.0 (70: 30) medium as well.
The content of 1-AP in the concentration range from 1.10(-6) to 1.10(-4) mol dm(-3) had no effect on the sensitivity of the determination of 1-NP, and vice versa. Due to the close peak potentials of 1-AP and 1-HP, the direct determination of their mixture using voltammetric methods is impossible.