An integrated microfluidic device for solid-phase extraction and spectrophotometric detection of opium alkaloids in...

A novel lab-on-chip integrated microfluidic device for solid-phase extraction (SPE) and spectrophotometric detection of morphine (MOR), codeine (COD), and papaverine (PAP) was developed. The extracted analytes were analyzed with a miniature UV-Vis spectrophotometer. The SPE adsorptive phase composed of polyurethane/polyaniline (PU/PANI) nanofibers was fabricated by electrospinning and in situ oxidative polymerization techniques. The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The main factors of extraction such as desorption conditions, pH, salt effect, and extraction time were investigated. The partial least square (PLS) regression was applied to improve the quantification of analytes. The linear dynamic ranges (LDRs) for MOR, COD, and PAP were 4-240, 4-210, and 1-150 ng mL^-1, respectively. Finally, the proposed method was successfully applied for the determination of MOR, COD, and PAP in human urine samples and the extraction recoveries were obtained in the range of 66.7-85.0% with RSDs < 8.3%.