High concentration of Cs is present in high-level radioactive waste. It is well-known that Cs is an alkali element and difficult to extract completely into an organic phase. Crown ether compounds are widely available for Cs extractants; DtBuDB18C6 (di-t-butyl-dibenzo-18crown6), was used in this study. Organic solvents used for the industrial applications, such as n-dodecane and 1-octanol, have low solubility concerning the compound; other solvents were employed and tested. In this study, ketone-, ether-, and ester-type solvents showed high solubility for DtBuDB18C6 and DtBuDB18C6, when dissolved in ketones and alcohols, exhibited relatively high Cs distribution ratios (D(Cs)), closely to 10.
The crystallization of the palladium(II) complex with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (HL) at the liquid-liquid interface was investigated in the heptane-toluene mixture/water system. Interfacial crystallization of PdLCl did not occur in the heptane/water system, whereas it occurred in the heptane-toluene mixture/water system. The crystal size distribution of PdLCl formed at the liquid-liquid interface strongly depended on the PdLCl solubility in the organic phase and the formation rate. Larger PdLCl crystals formed at the liquid-liquid interface under the higher toluene ratio, higher Pd(II) concentration and lower pH conditions.
A protein extraction and separation has been reported using the ionic liquid (IL)-based aqueous two-phase system (ATPS). Although ILs have many benefits, there was a problem of unfavorable physical properties such as high viscosity, or high-cost production of ILs. Recently protic ionic liquids (PILs) are emerging as an alternative to conventional ionic liquids. PILs are easily produced through a reaction between Brønsted acid and base at a relatively low cost. In this study, PILs (pyrrolidinium formate [Pyrr][HCOO] and propionate [Pyrr][C2H5COO] and inorganic salts (K3PO4, K2HPO4) as phase-forming constituents of ATPS, were used for the protein extraction.
From the binodal experiments, the phase separation abilities are [Pyrr][HCOO] > [Pyrr][C2H5COO] and K3PO4 > K2HPO4. Because proteins precipitated at the interface when using K3PO4, ATPS composed of [Pyrr][HCOO] and K2HPO4 was selected for the protein extraction. The proteins were successfully extracted to PIL-rich phase. The distribution ratio of each protein was in the order hemoglobin < cytochrome C < α-chymotrypsin < albumin. The partition behavior of proteins in PIL-based ATPS was complex and influenced by combined effect of hydrophobic, electrostatic interactions and salting out. FT-IR spectroscopic characterization indicated that secondary structures of hemoglobin and cytochrome C were retained in PIL-rich phase after extraction.
An effective sample preparation procedure using a house microwave-assisted extraction (hMAE) procedure, followed by cleaning with solid-phase extraction (SPE) by using HPLC with general UV-visible spectrometry was developed for residual 17α-methyltestosterone (MT) determination in Nile tilapia tissues. Our developed method showed a wide linear range from 25 to 800 ng g-1 with R2 as 0.9985 and presented a low detection limit of 1.53 ng g-1 with good precision. Evaluation of accuracy for the MT determination in real samples showed a great recovery percentage ranging from 98.41 to 100.78%. In conclusion, it can be said that the developed method has the potential for sample preparation when compared with another method, and can be used for the determination of MT residues in fish tissue with simplicity, rapidity, costeffectiveness, low solvent consumption, and minimum waste generation as well as having high accuracy and precision.