Preparation of 1-phenylmenthol from (−)-menthone as a template for molecularly imprinting and its subsequent adsorption

There is always a need to purify the desired product to remove unwanted impurities. The study aimed to synthesize 1-phenylmenthol by reducing menthone with the Grignard reagent, then use it as a template for the preparation of MIPs by precipitation polymerization. The product (1-phenylmenthol) was characterized by Fourier transform infrared (FTIR) spectroscopy and C and 1 H NMR spectroscopy. After polymerization, imprinted MIPs were washed with a mixture of acetic acid and methanol to remove the template. The Brunauer Emmett Teller (BET) results showed higher surface area (17.85 m 2 g −1 ), pore size (85.27 Å) and pore volume (0.038 cm 3 g −1 ) for the MIP as compared to NIP with the surface area of (10.05 m 2 g −1 ), pore size (70.69 Å) and pore volume (0.018 cm 3 g −1 ). Thermogravimetric (TGA) confirmed the stability of washed MIPs and NIPs up to 300 °C, as compared to unwashed MIP, which was gradually decreasing in weight from 100 °C. FTIR results indicated the presence of the template through a broad O H peak at a higher wavenumber of 3573 cm −1 , as well as strong C H stretching peaks from alkane groups, on unwashed MIPs. These peaks are absent in washed MIPs and NIPs, which do not contain the template. A series of parameters, including concentration, polymer mass, sample pH and contact time, was investigated. The high enrichment factor was achieved at a sample pH of 7. The optimum concentrations were 11 mg L −1 and 7 mg L −1 for MIP and NIP, respectively. The optimum mass of the polymer was determined to be 50 mg for MIP and 80 mg for NIP. The adsorption capacities of the MIP and NIP were found to be 191 mg g −1 and 68 mg g −1 , respectively The optimal adsorption time for 1-phenylmenthol was 180 min. • The molecularly imprinted polymer template was synthesized from (−)-menthone. • High surface area molecularly imprinted polymers were obtained after elution of 1-phenylmenthol. • High extractive performance of the molecularly imprinted polymers was observed.