Preconcentration of morphine in urine sample using a green and solvent-free microextraction method

Abstract

The ability of extraction and preconcentration of small amounts of substances from biological samples is very important in medical toxicology. On the other hand, minimal use of organic solvents is an important issue to prevent environmental damage. In the present study, we developed a new solid phase microextraction fiber using plant extracts as sorbent for extraction and preconcentration of morphine in urine sample. For this purpose, raw carbon nanotubes (CNTs) were functionalized with tobacco extracts. Functionalization was confirmed by Fourier transform infrared (FTIR) and Raman spectroscopy in addition to scanning electron microscope (SEM) images. The functionalized CNTs were coated on polypropylene hollow fiber. The results of HPLC analysis showed that the produced fiber could preconcentrate a very low concentration of morphine (0.25 ng/ml) in small volume of urine samples. Limit of detection (LOD) and limit of quantification (LOQ) for the produced fiber were determined 0.25 ng/ml and 0.825 ng/ml, respectively, and recovery of the fiber was determined 89% at LOQ. The produced fiber provided a recyclable and solvent free method for extraction of a trace amount of morphine, which can be successfully used for up to 30 times with no significant loss in the extraction efficiency.