Designing an absolutely solvent-free binary extraction system as a green strategy for ultra-trace analysis of chlorophenols

A new absolutely solvent-free based on dispersive magnetic micro-solid phase extraction (mu-MDSPE) in tandem with headspace-solid phase microextraction (HS-SPME) was developed and used for ultra-trace determination of chlorophenols (CPs) prior to GC-ECD analysis. Firstly, CPs were concentrated on magnetic graphene oxide (MGO) and then were thermally desorbed and reconcentrated on an SPME fiber (coated with ultra-porous electrospun PU/PS-SiO2 nanofibers) without using any organic solvents. The effective parameters of the system including MGO dose, sample volume, adsorption time, ionic strength, temperature, extraction time were investigated. The efficiency of the proposed method was also compared with that of single SPME, single MSPE, and coupled SPME-MSPE under the same experimental conditions. The proposed method showed considerably higher efficiency than the mentioned methods. The method was validated with obtaining low detection limits (3-28.4 ng L-1), wide linear dynamic range (10-5000 ng L-1) with R-2 > 0.9913 and RSD < 11.5%. It was finally applied for the determination of CPs in sewage water, rainwater and lemon juice samples and satisfactory recoveries (91-108%) with RSDs <= 12.7% were obtained.