Ultra-trace Determination of Preconcentrationed Naltrexone using Electromembrane Extraction followed by FFT Square Wave Admittance Voltammetry in Urine Samples

In the present paper, naltrexone determined at ultra-trace scale was performed by combining fast Fourier transform square wave admittance voltammetry with electromembrane extraction in urine samples. On this approach, a constructed three-microelectrode setup positioned at the upper end of the hollow fiber in a micro-pipette tip, which was then applied for the extracted analyte determination. The employed membrane was consisted 85% of 2-nitrophenyl octyl ether and 15% di-(2-ethylhexyl) phosphate immobilized in the pores of a hollow fiber. A DC potential of 150 V within the time of 25 min was applied, followed by the analytes migration from 1 mM HCl as the sample solution, through the supported liquid membrane into an acidic acceptor solution with pH 3.0 placed in the lumen of hollow fiber. Based on the obtained results, the introduced method exhibited one the linear range 5-1000 ng/mL (R2=0.993). Besides, the detection limit of 0.5 ng/mL was attained. Since the preconcentration factor was found to be 80 in the urine sample after the performed process, it can be concluded that the introduced method could be classified among qualified techniques for naltrexone detection in some complex samples.