Volume 69, Issue 11

Pharmacy staff and health care workers in hospitals may be exposed to antineoplastic drugs during cancer chemotherapy. Sensitive methods should be used to monitor the occupational exposure in biofluids such as urine. In this study, a sensitive method for cyclophosphamide determination in urine with high recovery was developed and validated for monitoring occupational exposure. Triple liquid-liquid extraction with ethyl acetate/dichloromethane (φ r = 3 : 1; 6.0 mL) was applied. Good separation of cyclophosphamide and ifosfamide was achieved in a 9.0 min analysis, using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). Limit of detection and limit of quantification were 0.07 ng mL −1 and 0.11 ng mL −1 , respectively. Repeatability (RSD, %) was ≤ 12.74 %. Inter-day and inter-analyst precision values (RSD, %) were ≤ 13.94 % and 12.59 %. Mean recovery for three different concentrations was (101.62 ± 6.05) %. The validation results were fitted for the purpose of routine monitoring of occupational cyclophosphamide exposure in hospital staff.

Legionella pneumophila may cause a fatal pneumonia in humans known as Legionnaires’ disease (LD). The strategies of L. pneumophila to adapt to and resist stressful environmental conditions include the ability to enter into a VBNC (viable but not culturable) state. The detection of L. pneumophila in environmental samples benefits from the use of standardised methods: for detection and enumeration following membrane filtration (AFNOR T90-431, ISO 11731) and detection and quantification by polymerase chain reaction PCR (AFNOR T90-471, ISO 12869). Culture is hampered by its inability to detect VBNC forms and PCR is unable to discriminate between live and dead bacteria. The present immunosensor was obtained by the immobilisation of a monoclonal anti-L. pneumophila antibody (MAb) on an indium-tin oxide (ITO) electrode by the self-assembled monolayers (SAMs) method using an aminosilane. The immunosensor was characterised by wettability (contact angle measurement), atomic force microscopy (AFM), confocal laser scanning microscopy (CLSM), and electrochemical impedance spectroscopy (EIS). A limit of detection of 10 bacteria per mL was observed on artificial samples.

One-dimensional (1D) Ag/AgBr/TiO 2 nanofibres (NFs) have been successfully fabricated by the one-pot electrospinning method. In comparison with bare TiO 2 NFs and Ag/AgBr/PVP (polyvinylpyrrolidone) NFs, the 1D Ag/AgBr/TiO 2 NFs photocatalyst exhibits much higher photocatalytic activity in the degradation of a commonly used dye, methylene blue (MB), under visible light. The photocatalytic removal efficiency of MB over Ag/AgBr/TiO 2 NFs achieves almost 100 % in 20 min. The photocatalytic reaction follows the first-order kinetics and the rate constant (k) for the degradation of MB by Ag/AgBr/TiO 2 NFs is 5.2 times and 6.6 times that of Ag/AgBr/PVP NFs and TiO 2 NFs, respectively. The enhanced photocatalytic activity is ascribed to the stronger visible light absorption, more effective separation of photogenerated electron-hole pairs, and faster charge transfer in the long nanofibrous structure. The Ag/AgBr/TiO 2 NFs maintain a highly stable photocatalytic activity due to its good structural stability and the self-stability system of Ag/AgBr. The mechanisms for photocatalysis associated with Ag/AgBr/TiO 2 NFs are proposed. The degradation of MB in the presence of scavengers reveals that h + and • O − 2 significantly contribute to the degradation of MB.

The present study reports the preparation and characterisation of Ce(III) immobilised on an aminated epichlorohydrin-activated agarose matrix (CAEA) as a “green” catalyst. The catalyst was synthesised by the reaction of the epichlorohydrin-activated agarose matrix with ammonia solution, which was then treated with Ce(NO 3 ) 3 · 6H 2 O. The catalyst (CAEA) was characterised by FT-IR, far IR, CHN, XRD, TGA, and ICP techniques. CAEA is shown to be an effective and reusable heterogeneous catalyst for the transamidation of carboxamides with amines under solventfree conditions. The catalyst was successfully applied to the synthesis of a wide range of aromatic and aliphatic amides. High efficiency, mild reaction conditions, easy work-up, simple separation and also reusability are important advantages of this catalyst.

The present study investigated the impact of the driving force (Δp) on the transport properties. All the experiments and calculations were performed for air-gap membrane distillation (AGMD). In the course of the experiments, it was found that an identical value of Δp could be attained by applying different values of feed and permeate temperatures. It was highlighted that constant values of water fluxes could be achieved using the constant driving force created by different temperatures. Moreover, the relation between ln(J H₂O ) and 1/Tf was shown to be linear only for the J H₂O created at ΔT = T f - T p > 35 K. This work’s significant finding was to highlight the limitation of the Arrhenius-type equation applied in the activation energy calculations.

The chemical structures of Miscanthus var. ‘Soranovskii’ lignin fractions released via extraction of lignin from the lignocellulosic feedstock using moderately heated acetone under atmospheric pressure, without acidic and alkaline catalysts, were studied. A blend of Miscanthus stems and leaves was pretreated with water under thermobaric conditions. The acetone organosolv process subsequently afforded a substance related to a lignin-like matter-acetone organosolv Miscanthus lignin (AOML). Non-destructive analytical techniques such as FTIR spectroscopy, gas chromatography-mass spectrometry, size-exclusion chromatography, and 2D NMR were used. The IR and NMR spectroscopies revealed the AOML structure to comprise all the three major types of phenylpropane units: guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H). The resultant acetone-organosolv lignin exhibits good solubility in polar solvents, moderate solubility in aromatic chemicals, and is insoluble in non-polar solvents, exhibiting the physicochemical properties of a thermoplastic polymer with a softening point of 67.0°C (onset 33.0°C, endset 81.5°C).

This study investigated the potential use of waste cooking oil (WCO) in the production of engine fuels and valuable chemicals via catalytic cracking. WCO was processed in its pure form and in a mixture with hydrotreated vacuum gas oil (HVGO). Catalytic cracking experiments were performed using a microactivity test (MAT) (simulation of the fluid catalytic cracking environment). In cracking over the standard fluid catalytic cracking equilibrium catalyst (FCC-ECAT), the oxygen contained in the feed was consumed in the formation of CO and CO 2 , water and into oxygenated organic compounds (phenolics, esters, carboxylic acids, etc.), which were found in the organic phase of the liquid product. In order to remove the unwanted organic oxygenates, the catalytic system based on pure FCC-ECAT was modified by addition of the ZSM-5-based FCC catalyst. By using the mixture containing FCC-ECAT and 10 mass % of FCC-ZSM-5, it was possible to reduce the amount of organic oxygenates to almost the feasible minimum when cracking pure WCO. The effect of the catalyst mixture on cracking the feed mixture of the vacuum gas oil with 10 vol. % of WCO was manifested in the practically zero formation of organic oxygenates and in a gasoline yield comparable with vacuum gas oil (VGO) cracking

In this paper, an ionic liquid-based aqueous two-phase system (ILATPS) was applied to the chiral separation of α-cyclohexylmandelic acid (α-CHMA) enantiomers with hydroxypropyl-β- cyclodextrin (HP-β-CD) as the chiral selector. Several influencing parameters were investigated including the types and concentration of ionic liquids, the amount of phase-forming salt, temperature, mixing time, pH, and the content of HP-β-CD. The results showed that not all ILATPS had the ability to chirally recognise the selected enantiomers and that [C 4 mim]BF 4 /(NH 4 ) 2 SO 4 -based ATPS possessed the best enantioseparation ability of the investigated ILATPSs. Under optimal conditions, the separation factor (α) attained 1.59 in a single-step extraction. ILATPS is much “greener” than other liquid-liquid extraction systems, showing its potential for application to the chiral separation.

In the study, a thermally activated sodium peroxydisulphate (PDS; Na 2 S 2 O 8 ) was applied in order to disintegrate wastewater activated sludge (WAS). Chemical disintegration of WAS results in organic matter and polymer transfer from the solid phase to the liquid phase. Soluble chemical oxygen demand (SCOD) is often used to characterise the disintegration efficiency of WAS flocs and microorganisms cells. The present study was conducted in order to chemically disintegrate WAS using PDS in doses of 0.2 %, 0.4 %, 0.6 %, 0.8 % and 1.0 % activated at temperatures of 50°C, 70°C and 90°C for 30 min. The temperature rise induced the PDS to form free radicals, which resulted in an increase in SCOD, i.e. for the highest dose of PDS, the SCOD value attained 2140 mg dm −3 (almost a 15-fold increase over the WAS value). A further positive effect from using this method was a decrease in the sludge volume index (SVI) from 89.8 cm 3 g −1 to 30.6 cm 3 g −1 . On the basis of the results obtained, it may be concluded that thermally activated PDS is suitable for disintegration and has a positive impact on WAS sedimentation properties.

The freeze-drying method of metal oxides synthesis has a number of advantages such as high homogeneity, varying porous structures, morphologies and uniform particle size distribution, etc. Because of these advantages, the binary metal oxides ZnO, TiO 2 and ternary metal oxide ZnTiO 3 were synthesised by the freeze-drying method. The synthesised materials were characterised by X-ray diffraction (XRD), Fourier transform-infra red spectroscopy (FT-IR), UV-VIS spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). The as-synthesised metal oxides were calcined at different temperatures to study the phase evolution and morphological changes. The crystalline cubic-phase ZnTiO 3 (a = 8.3948 Å) was obtained on calcination of the precursor at 600°C, and decomposed to the cubic phase Zn 2 TiO 4 (a = 8.4580 Å and rutile TiO 2 (a = 4.5955 Å and c = 2.9593 Å) at 1000°C. The band gap of ZnO (3.28-3.10 eV), TiO 2 (3.37- 2.97 eV) and ZnTiO 3 (3.92-3.80 eV) calculated using Tauc’s relation was found to vary inversely with calcination temperature and phase transition.

Nanorod vanadatesulfuric acid (VSA NRs), as a recyclable and eco-benign catalyst, was used for one-pot synthesis of 2,4,5-trisubstituted imidazoles and 1,2,4,5-tetrasubstituted imidazoles using aldehydes, benzil, benzoin or 9,10-phenanthrenequinone and ammonium acetate or aniline under solvent-free conditions providing high to excellent yields. VSA is easily prepared by a simple reaction of chlorosulfonic acid and sodium metavanadate in high purity. As compared with the conventional procedures, the present protocol offers several advantages such as simplicity of procedure, short reaction time, high yields, easy workup, recoverability and reusability of the catalyst and simple purification of the products.

An efficient method was developed for synthesising isoxazoles. A series of novel bis-isoxazole ether compounds VI, VII and VIII were synthesised starting from different substituted aldehydes (I) via a 1,3-dispolar cycloaddition using Zn/Zn 2+ as a catalyst; these were characterised by FT-IR, HRMS, 1 H NMR and 13 C NMR spectroscopy. In addition, the antimicrobial properties of the synthesised products were investigated. The synthesised compounds exhibited significant antifungal activities in comparison with the standard drugs, fluconazole and itraconazole. It was found that Candida albicans was sensitive to 2-substituted phenyl bis-isoxazole ethers bearing pyridyl.

Linear ABC triblock copolymer PtBA 154 -b-PS 300 -b-P2VP 240 was successfully synthesized by RAFT polymerization. Block copolymer micelles were prepared by the two-step hierarchical selfassembly process. Size exclusion chromatography and 1 H NMR were used to characterize the structure of samples. Morphologies and size of micelles were determined by transmission electron microscope. The results showed that the densely dispersed spherical micelles of PtBA 154 -b-PS 300 -b-P2VP 240 were obtained in the first step of the hierarchical self-assembly process. In the second step, core-compartmentalized micelle strings with different lengths and distribution densities were obtained when the primary self-assembled solution was dialyzed in distilled water with pH ≈ 3. When distilled water with pH ≈ 3 was added drop-wise to this solution, uniformly dispersed spherical core-compartmentalized micelles of PtBA 154 -b-PS 300 -b-P2VP 240 were prepared. Thus, hierarchical self-assembly structure of linear ABC triblock copolymer was obtained successfully and the preparation of uniformly dispersed spherical micelles of triblock copolymers was realized simply by changing the secondary self-assembly methods.