Improved freeze-dried kit for the preparation of 188ReN-DEDC/lipiodol for the therapy of unresectable hepatocellular carcinoma.

Rhenium-188-N-(DEDC)2/lipiodol (abbreviated as 188ReN-DEDC, where DEDC = monoanionic diethyldithiocarbamate) is a clinically proven radiopharmaceutical for the therapy of unresectable hepatocellular carcinoma (HCC) through trans arterial radioembolization (TARE). A two-vial freeze-dried kit for the preparation of [188ReN(DEDC)2] complex using sodium perrhenate (Na188ReO4) obtained from a commercial Tungsten-188/Rhenium-188 generator had been reported earlier. This method required addition of stipulated volume of glacial acetic acid into vial 1 by the user for efficient preparation of [188ReN]2+ intermediate. An error in this step can result in low radiochemical yield of [188ReN]2+ intermediate as well as sub-optimal pH of the reaction mixture for the second step, leading to poor radiochemical purity of 188ReN-DEDC complex. In the present work, a solution to this problem was found by including an oxalate buffer of pH = 3 in vial 1, eliminating the need for the addition of glacial acetic acid by the user. This modification not only made the kits more user-friendly, it resulted in significant improvement in the kinetics of formation of [188ReN]2+ intermediate, wherein > 95% radiochemical purity could be achieved within 5 min incubation at ambient temperature. Moreover, the novel route for the preparation of [188ReN]2+ intermediate may be applied to any radiopharmaceutical based on 188ReN-core.

A general strategy to prepare SERS active filter membranes for extraction and detection of pesticides in water.

An important feature in the fabrication of surface-enhanced Raman scattering (SERS) platforms is, together with the high efficiency, to allow the rapid collection and analysis of a vestigial analyte. Conventional substrates based on rigid solid materials or metal hydrosols are not suitable for sample extraction, limiting their application in areas such as water quality monitoring. Herein, we have developed a strategy to fabricate SERS active substrates (Ag/LCP) based on liquid-crystal polymer (LCP) textile fibers decorated with Ag nanoparticles (NPs). Two distinct methods for substrate preparation envisaging the SERS detection of the pesticide thiram have been explored in this research. In a first stage, we have investigated the usefulness of both approaches using ethanolic solutions of the pesticide thiram, and after real samples spiked with thiram were used to explore the analysis in real environment. The SERS analysis of thiram dissolved in Aveiro Estuary water and in fruit juices have provided enhancement factors of 1.67 × 107 and 3.86 × 105, respectively, using the Ag/LCP composites. Noteworthy, in the latter case, the detection limit (0.024 ppm) achieved is lower than the maximal residue limit (MRL) of 5 ppm in fruit, as prescribed by European regulations (EU) 2016/1. Moreover, the selectivity of the SERS substrates for different pesticides was also evaluated, analyzing distinct pesticides such as paraquat and sodium diethyldithiocarbamate. SERS active Ag/LCP/PA filter membranes were also prepared using Ag/LCP composites supported by a polyamide (PA) filter, which can be an easy alternative to prepare simple, highly efficient and low-cost SERS active filter membranes for water analysis.

A new supramolecular based liquid solid microextraction method for preconcentration and determination of trace bismuth in human blood serum and hair samples by electrothermal atomic absorption spectrometry.

A simple and reliable supramolecule-aggregated liquid solid microextraction method is described for preconcentration and determination of trace amounts of bismuth in water as well as human blood serum and hair samples. Catanionic microstructures of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) surfactants, dissolved in deionized water/propanol, are used as a green solvent to extract bismuth (III)-diethyldithiocarbamate complexes by dispersive microextraction methodology. The extracted solid phase is easily removed and dissolved in 50 µL propanol for subsequent measurement by electrothermal atomic absorption spectrometry (ET-AAS). The procedure benefits the merits of supramolecule aggregates' properties and dispersive microextraction technique using water as the main component of disperser solvent, leading to direct interaction with analyte. Phase separation behavior of extraction solvent and different parameters influencing the extraction efficiency of bismuth ion such as salt concentration, pH, centrifugation time, amount of chelating agent, SDS:CTAB mole ratio, and solvent amounts were thoroughly optimized. Under the optimal experimental conditions, the calibration curve was linear in the range of 0.3-6 µg L-1 Bi (III) with a limit of detection (LOD) of 0.16 µg L-1 (S/N = 3). The relative standard deviations (RSD) of determination were obtained to be 5.1 and 6.2 % for 1 and 3 µg L-1 of Bi (III), respectively. The developed method was successfully applied as a sensitive and accurate technique for determination of bismuth ion in human blood serum, hair samples, and a certified reference material.

Acid modified diatomaceous earth--a sorbent material for thin layer chromatography.

Natural diatomaceous earth (DE) is modified by flux calcination and refluxing with acid. To characterize natural DE, modified DE's [flux calcinated (FC)DE and FCDE-I] and silica gel 60GF(254) (Si-60GF(254)) are analyzed microscopically, physically, and chemically by various techniques. FCDE-I and Si-60GF(254) are investigated for their usefulness in the stationary phase of thin layer chromatography (TLC) both individually and in composition. Sodium diethyldithiocarbamate (DEDTC) and ammonium pyrrolidinedithiocarbamate (PyDTC) are prepared as Co or Cu (M) complexes [M(DEDTC)(2) and M(PyDTC)(2), respectively]. These complexes and their mixtures are run on thin layers of Si-60GF(254) and FCDE-I individually, and on various FCDE-I and Si-60GF(254) mixtures. Pure toluene and various toluene-cyclohexane mixtures (3:1, 1:1, 1:2, 1:3, v/v) are used as mobile phases for the running the complexes. The best analytical separations of both M(DEDTC)(2) and M(PyDTC)(2) complexes are obtained when using pure toluene and toluene-cyclohexane (3:1, 1:1, v/v) as mobile phases on FCDE-I-Si-60GF(254) (1:3, 1:1, w/w) layers as stationary phases. This study shows that it is possible to qualitatively analyze and to satisfactorily separate a mixture Cu(2+) and Co(2+) cations on cited chromatographic systems.