ABSTRACT
Molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using ribavirin as the template molecule and methacrylic acid as the functional monomer.The sensitive film of ribavirin electrode was constructed by molecularly imprinted polymer doped with graphene oxide as the ionophore, poly(vinylchloride) (PVC) as matrix and dioctyl sebacate for plasticizer.The results showed that the best performance of the electrode was obtained when the sensitive film compositions were 100.8 mg of MIP, 14.7 mg of GO, 450.8 mg of PVC and 901.6 mg of dioctyl sebacate, and the inner filling solution composition was 0.1 mol/L NaCl + 0.05 mol/L NaAc-0.05 mol/L HAc + 1.0×10.-5 mol/L ribavirin solution.The electrode showed a near-Nernstian slope of 45.565 mV/decade for ribavirin over the range of 1.0×10.6-1.0×10.-4 mol/L and a detection limit of 1.0×10.-7 mol/L.The electrode could be used in the pH range of 3 to 5 with response time of less than 3 min.The developed electrode exhibited high selectivity for ribavirin and was successfully applied to the determination of ribavirin in feed and injection with recoveries of 90%-110% and RSD of 3.0%-7.9%.
ABSTRACT
Double template molecularly imprinted polymer ( D_MIP) was prepared by emulsion polymerization method using the nonylphenol (NP), bisphenol A (BPA) as templates, α_methyl methacrylate(MAA) as functional monomer. Then using the D_MIP as solid phase extraction materials, a method based on double_molecularly imprinted solid phase extraction coupled with high performance liquid chromatographic fluorescence detection was developed for the determination of trace NP and BPA from environmental and food samples. The D_MIP was characterized by Fourier transform infrared spectroscopy ( FT_IR ) and adsorption experiments. The results showed that the saturated adsorption capacity of the D_MIP for NP and BPA was 73. 3 and 97. 5 mg/g, respectively, and the relative selectivity coefficient was 2. 2 and 1. 7, respectively. Moreover, the conditions affecting extraction efficiency, such as washing conditions and desorption conditions were optimized. Under the optimal conditions, there was a good linear correlation in the concentration range of 0. 01-2. 3 mg/L with correlation coefficients (R2) greater than 0. 998 for NP and BPA. The detection limits ( S/N=3) were 0. 001 and 0. 002 mg/L. The proposed method was applied to determine NP and BPA in river water, beer and crucian carp samples. The recoveries of NP and BPA were in the range of 86. 4%-99. 1%with the relative standard deviation less than 6 . 2%. This method has good selectivity and high sensitivity and shows good prospects for the application in the enrichment and separation of NP and BPA in real samples.
ABSTRACT
A novel method for the determination of glucose was reported. Based on a reverse photoinduced electron transfer process, we can quickly determine the concentration of glucose in the sample. A fluorescent boronic acid, dapoxylTM 3-sulfonamidophenylboronic acid was first used for the determination of glucose. This linear range is 0～1×10－2 mol/L, the detection limit is 5×10－5 mol/L. This method has been applied to direct determination of glucosein in three kinds of serum samples with satisfactory results, the RSD is less than 4%.