Quantitative determination of phenol in natural decayed leaves using procaine modified carbon paste electrode surface by cyclic voltammetry

摘要

In this research, the amount of phenol in decayed leaves was quantified in aqueous medium by using procaine hydrochloride modified carbon paste electrode. Working electrode was prepared by using homogeneous mixture of graphite powder and mineral oil (80:20%). The mixture was pressed on the electrode surface thus a glassy form was obtained. The electrode surface was modified with procaine hydrochloride in 0.1 M tetrabutylammonium tetrafluoroborate using 100 mVs~(-1) scanning rate between -1.7 V and -0.5 V with 50 cycles. After the modification process, the electron transfer becomes easier and faster. For the calibration curve, a series of standard phenol solution between 1.0 × 10~(-3) M and 1.0× 10~(-8) M was prepared using Britton-Robinson buffer solution at pH 12. The prepared standard solutions were used for the chemical binding of phenol to the modified electrode surface between 0.0 V and + 0.9 V potential range using 100mVs~(-1) scanning rate with 10 cycles. Calibration curve was obtained by plotting concentrations versus peak currents of standard phenol solutions. By using this calibration method, the amount of phenol was determined as 8.33 × 10~(-5) M in natural decayed leaves in BR buffer solution at pH 12. Detection limit was obtained as low as 1.0×10~(-8) M.