A core/shell TiO2 magnetized molecularly imprinted photocatalyst (MMIP@TiO2): synthesis and its photodegradation activity towards sulfasalazine.

Although the selectivity of TiO2 for the degradation of target molecules is not enough, it is a broadly employed photocatalyst for the degradation of many pollutants. Molecularly imprinted compounds owing to their extreme recognition specificity have become increasingly popular for preparing selective photocatalysts. In this work, based on molecularly imprinted magnetized TiO2 (MMIP@TiO2), a selective photocatalyst was prepared. Via the co-precipitation method, Fe3O4 particles were prepared and coated respectively by SiO2, vinyl end groups, and molecularly imprinted polymers (MIP). The synthesized photocatalyst was characterized by the X-ray diffraction method (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive x-ray spectrometry (EDX), vibrating sample magnetometry (VSM), high-performance liquid chromatography (HPLC), and photoluminescence analysis (PL). The photocatalyst was then used to degrade the sulfasalazine pharmaceutical pollutant under UV irradiation. An average crystallite size of 9 nm was obtained for the MMIP@TiO2 sample from the Scherrer formula and 34.5 nm by the Williamson-Hall formula. The results revealed that compared to the non-imprinted counterpart, the molecularly imprinted photocatalyst had significantly higher efficiency and selectivity for the degradation of target molecules. The process was forwarded with 90% efficiency within 10 min. Optimal conditions were 10.0 min irradiation when 25 mL SSZ solution (50 mg/L), 0.07 g/L catalyst dose, and pH 6.0 were applied. The maximum removal efficiency was calculated to be 92%. The external magnetic field quickly removed the photocatalyst from the solution and regenerated it. It was revealed that after each regeneration cycle, the efficiency dropped. Nevertheless, 63% of the preliminary effectiveness remained after four regeneration steps.

Investigation of the possibility of fermentation of red grape juice and rice flour by Lactobacillus plantarum and Lactobacillus casei.

The aim of the current study was to evaluate the possibility of the bacterial growth and substrate metabolism during the fermentation of red grape juice and the mixture of red grape juice and rice flour solution using Lactobacillus plantarum and Lactobacillus casei. In recent years, cereal-based beverages have been used as functional compounds such as antioxidants, dietary fiber, minerals, probiotics, and vitamins in diets. In this research, fermentation of red grape juice (media 1) and 1:1 mixture of red grape juice and rice flour solution (media 2) by two strains of gram positive and homofermentative lactic acid bacteria: L. plantarum and L. casei (individually and mixed) was examined. Fermentation was carried out at 37°C for 48 hr. Microbial population, pH, acidity, sugar, and organic acid metabolism were measured during the fermentation period. Data showed that in media 2 fermented with mixed culture of both L. plantarum and L. casei, acidity and microbial population increased sharply at the initial stages of fermentation, and the most percentage of lactic acid production occurred. Red grape juice fermented with mixture of L. plantarum and L. casei showed the most sugar consumption (p < .05). Results indicated that the use of the mixture of red grape juice and rice flour solution can be a proper substrate for producing lactic acid.

High performance liquid chromatographic determination of ultra traces of two tricyclic antidepressant drugs imipramine and trimipramine in urine samples after their dispersive liquid-liquid microextraction coupled with response surface optimization.

Dispersive liquid-liquid microextraction (DLLME) coupled with high performance liquid chromatography by ultraviolet detection (HPLC-UV) as a fast and inexpensive technique was applied to the determination of imipramine and trimipramine in urine samples. Response surface methodology (RSM) was used for multivariate optimization of the effects of seven different parameters influencing the extraction efficiency of the proposed method. Under optimized experimental conditions, the enrichment factors and extraction recoveries were between 161.7-186.7 and 97-112%, respectively. The linear range and limit of detection for both analytes found to be 5-100ng mL(-1) and 0.6ng mL(-1), respectively. The relative standard deviations for 5ng mL(-1) of the drugs in urine samples were in the range of 5.1-6.1 (n=5). The developed method was successfully applied to real urine sample analyses.