| Abstract: | Methyl parathion (MP) is a highly toxic organophosphate and its exposure may lead to substantial adverse effects to human health. The existence of 4‐nitrophenol (4‐NP) in the form of free phenol, glucuronide (4‐NP‐G) or as a sulfate ester (4‐NP‐S) can be used as biomarkers to assess the duration and extent of MP exposure. In this work, a MC‐CE device incorporating post‐CE amperometric detection using multi‐walled carbon nanotubes (MWNTs) modified carbon fiber microelectrode (CFME) was fabricated and assessed for simultaneous determination of 4‐NP, 4‐NP‐G, and 4‐NP‐S in human urine. The detection sensitivity and stability was greatly enhanced by the modification of MWNTs. The capability of the MC‐CE device with dual MWNTs modified CFME for detecting impurity was assessed and reliability established by high recoveries from 95 to 97% for spiked MP biomarkers. The method developed is shown to provide a simple, sensitive, and reliable means for monitoring 4‐NP, 4‐NP‐G, and 4‐NP‐S in human urine. |
