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Fe3O4@Ionic liquids ß-cyclodextrin polymer(Fe3O4@ mono-6- deoxy-6- (1-ethyl- imidazolium)-ß-cyclodextrin iodide polymer, ILs-ß-CDCP) was prepared. A novel method based on Fe3O4@ILs-ß-CDCP solid phase extraction coupled with fluorescence spectrophotometry for Rhodamine B (RhB) determination, was investigated. Results were shown that RhB was adsorbed on Fe3O4@ILs-ß-CDCP and eluted with sodium dodecyl sulfate (SDS) (1.0%) rapidly. Different parameters, such as pH, adsorption time and volume, eluent volume and time were studied. This method introduced linearity for RhB between 0.01-9.00 µg/mL-1 , the limit of detection was 5.2 ng/mL-1 , correlation coefficient (R) was >0.9987 and the relative standard deviation (RSD) was 3.1% (n = 3, c = 4.00 µg/mL). The mechanism of adsorption of RhB on Fe3O4@ILs-ß-CDCP was studied through the FTIR analysis and the inclusion constant of Fe3O4@ILs-ß-CDCP-RhB. This method was applied successfully for determination of RhB in real samples with satisfactory results.

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RESUMEN

In this paper, carboxymethyl-hydroxypropyl-ß-cyclodextrin polymer modified magnetic particles Fe3O4 (CM-HP-ß-CD- CP-MNPs) were prepared and applied to magnetic solid phase extraction of malachite green combined with UV-Visible spectrom- etry detection. The synthesized magnetic particles were characterized by element analysis, Fourier transform infrared spectra and transmission electron microscopy. Several variables affecting the extraction and desorption of malachite green such as pH, the amount of adsorbent, the type and volume of eluent, extraction and desorption time, and temperature were investigated. Under the optimum conditions, malachite green could be adsorbed by CM-HP-ß-CDCP-MNPs (RE% = 92), and elution by C2H5OH (EE% = 90). the preconcentration factor of the proposed method was approximately 7.5, the CM-HP-ß-CDCP-MNPs could be used repeatedly for 5 times and offered better recovery. The linear range and detection limit (DL) were found to be 0.08~8.00 µg · mL⁻¹ and 5.6 ng · mL⁻¹ respectively. This technique had been successfully applied to the determination of malachite green in real samples. The inclusion interaction of CM-HP--CDCP-MNPs with malachite green was studied through FTIR.

RESUMEN

A simple and sensitive spectrofluorimetric method has been developed for the determination of clopidogrel sulfate in pharmaceutical formulation and human urine/serum. It is based on the formation of ion-pair complex between clopidogrel sulfate and alizarin red in 0.3 mol x L(-1) hydrochloric acid solution. The ion pair complex was extracted in dichloromethane and the fluorescence intensity was measured at 550 nm after excitation at 428 nm. The various factors influencing ion-pair complex formation and fluorescence determination were discussed. Under the optimized conditions, the fluorescence value showed a good linear relationship with the clopidogrel sulfate concentration ranging from 1.0 to 11.0 µg x mL(-1). The equation of calibration curve was F = 53.32 + 35.01c (µg x mL(-1)), r = 0.994, and the detection limit was found to be 0.11 µg x mL(-1). No interference was observed from common co-existing substances or pharmaceutical excipient. The determination recoveries of clopidogrel sulfate in pharmaceutical formulation and human urine/serum samples were 90.6%-99.3%, 104.6%-109.3%, 96.3%-105.0%, respectively. The method was successfully applied to detect clopidogrel sulfate in clopidogrel sulfate tablet and human urine/ serum. The obtained results of clopidogrel sulfate tablet were in good agreement with the results of HPLC. Therefore, it is concluded that the proposed method is simple, sensitive and rapid for the determination of clopidogrel sulfate in real samples.

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Ionic liquids functionalized ß-cyclodextrin polymer, a mono-6-deoxy-6-(1,2-dimethylimidazolium)-ß-cyclodextrin iodide polymer (ILs-ß-CDCP), was synthesized as a solid-phase adsorbent coupled with high-performance liquid chromatography for separating or analyzing magnolol in drug samples. The results showed that magnolol was adsorbed rapidly on ILs-ß-CDCP and eluted with methanol. Under the optimum conditions, preconcentration factor of the proposed method was 12. The linear range, limit of detection (LOD), correlation coefficient (R) and relative standard deviation (RSD) were found to be 0.02-8.00 µg/mL, 1.9 ng/mL, 0.9992 and 2.76% (n=3, c=2.00 µg/mL), respectively. The interaction between ILs-ß-CDCP and magnolol was studied through the inclusion constant, FTIR and TGA analysis. This proposed method has been successfully applied to the determination of magnolol in real samples.

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A rapid, novel spectrofluorimetric method to determine epristeride (EP) in biological fluids and a pharmaceutical formulation was developed, based on the fact that fluorescence intensity of l-tryptophan could be quenched by EP in the medium of pH=9.0. The various factors influencing fluorescence quenching were discussed. The quenching mechanism was investigated with the quenching type, synchronous fluorescence spectra and quantum efficiency. Under the optimized conditions, fluorescence quenching value (ΔF=Fl-tryptophan-FEP-l-tryptophan) showed a good linear relationship with the EP concentration ranging from 0.4 to 12.0 µg/mL. The linearity, recovery and limit of detection demonstrated that the proposed method was suitable for EP determination in biological fluids and EP tablets. The method was successfully applied to the analysis of EP in real samples and the obtained results were in good agreement with the results of the official method.

RESUMEN

In the present paper, the hydrophobicity ionic liquid 1-butyl-3- methylimidazolium hexafluorophosphate ([C4mim] [PF6]) was synthesized with 1-methylimidazole and butylbromide and equimolar ammonium hexafluorophosphate, which was applied to preconcentration for trace gold. The factors which may affect preconcentration of gold were investigated. The experimental results showed that the absorbance was linear when the concentration of gold was in the range of 0.40-16.00 microg x mL(-1), with linear equation A = 0.007 63c + 0.073 87(c:microg x mL(-1)), correlation coefficient r = 0.999 1, and detection limit 0.072 microg x mL(-1). The method was applied to the determination of trace gold in water samples satisfactorily.

RESUMEN

In the present article, the sensitizing effect of Triton X-100 microemulsion media (Triton X-100-M) on the determination of L-tryptophan by fluorescence spectrophotometry was studied, which was based on a strong fluorescence substance produced when L-tryptophan was oxidized by Ce4+ in acid medium. Compared with Triton X-100 micelle (Triton X-100-m), it was found that in the medium of Triton X-100-M the intensity of fluorescence was enhanced by 225 times. Various factors that influence fluorescence determination and interfering ions were examined. The mechanism of sensitizing effect of Triton X-100 microemulsion was also discussed. Under the optimum conditions, the liner range and detection limit are 0.1-1.0 g x mL(-1) and 0.09 microg x mL(-1) (correlation coefficient r = 0.998 4), respectively. The linear equation was F = 342.37+30.45c. The proposed method has been successfully applied to determine food samples.

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