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چکیده
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In the present study, we introduce a new and simple method for the extraction and determination of chrysophanol in urine samples using molecularly imprinted solid-phase microextraction fiber. The fiber was built by using chrysophanol as a template, vinyl imidazole as a functional monomer, and tragacanth gum as a natural crosslinker, on the surface of polydopamine functionalized stainless steel wire by radical polymerization to construct long-lasting stable fiber (MIP-SPME fiber). The important variables that affect the fiber extraction efficiency, including; pH, extraction time, extraction temperature, desorption time, salt concentration, and stirring rate were optimized by fractional factorial design followed by central composite design studies. Results showed that the adsorption of chrysophanol on MIP-SPME fiber was pH and temperature dependent with maximum uptake in the pH 3 and 30 ◦C, respectively. In addition, the highest fiber efficiency was observed in 15 min and 10 min extraction and desorption time, respectively. The High-performance liquid chromatography (HPLC-UV) was used to assess the fiber’s performance in the determination of chrysophanol in a urine sample. Other properties of fiber were also studied by complementary tests such as adsorption and extraction capacity experiments. The mechanism of adsorption follows the Langmuir model, with a maximum adsorption capacity of 131.77 ng. The limit of quantification was 8.95 ng mL 1. The recovery for the spiked sample ranged from 94.01% to 96.20%, with a relative standard deviation of 4.30% to 5.06% for single fiber and between fibers, respectively. The curve calibration plots are linear over the concentration range of 0.007 – 0.2 μg mL 1 for chrysophanol. The proposed method was successfully applied to the extraction and determination of chrysophanol in urine samples.
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