چكيده به لاتين
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are persisted organic pollutant which have two or more fused benzene rings. They are widely distributed environmental contaminants that have hazardous biological effects, toxicity, and carcinogenicity. They originated from incomplete pyrolysis of organic compound. Some techniques such as adsorption, photolysis and volatilization are used in the determination of PAHs, which between these methods, adsorption is the best method. Mechanical stir bar sorptive extraction is a new format of stir bar sorptive extraction. In this method, for the first time, sorbent was coated on the mechanical stir bar and could overcome on some defects of stir bar sorptive extraction. In the present work, Polyacrylonitrile nanofibers was coated on a mechanical stir bar by electrospinning method and used in mechanical stir bar sorptive extraction of PAHs in water samples coupled with gas chromatography with flame ionization detector. To reach the optimum extraction efficiency, affecting parameters, including sorption and desorption time, sample volume and stirring rate were investigated by a central composite design. Optimum conditions were 18 minutes, 6 minutes, 9 millilitre and 1050 rpm, for mentioned parameters, respectively. Under optimum conditions the calibration curves in the range of 10-2000 ng/mL for naphthalene and 5-2000 for acenaphthene, anthracene and phenanthrene. The limits of detection (LOD) and limits of qualification (LOQ) were 0.008-0.4 ng/mL and 0.02-1.32 ng/mL, respectively. The relative standard deviation (RSDs) for four analytes at a concentration in 20 ng/mL were less than 12%. Recovery and enrichment factor were in 84-104 and 120-126, respectively.
Keywords: Mechanical stir bar sorptive extraction; Polycyclic aromatic hydrocarbons; Gas chromatography; Electrospinning; Nanosorbent
