We report a colorimetric method for determining lithium in blood serum without sample pretreatment or solvent-extraction steps. The method is based on a novel chromogenic ionophore that exhibits exceptionally high selectivity (much greater than 4000:1) for lithium over sodium. The standard curve for the method is linear up to 3.5 mmol/L and exceeds the therapeutic range for lithium. The results...

Small molecule diversity can be achieved in a single synthetic operation from bifunctional substrates in the absence of additives and under the influence of microwaves with complete control of pathway selectivity. The preliminary Ugi four-component coupling products give rise to three structurally distinct scaffolds that are dependent on solvent effects and sterics. 2,5-Diketopiperazines (Type ...

A La-MnO2 catalyst exhibited excellent performance in aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). Characterization the samples revealed that loose surface morphology and high oxygen species mobility facilitated HMF reaction. H2O was verified as a good solvent for formation FDCA because facilitation aldehyde group hydration generate carboxyl on molecu...

Gravimetric fat data were obtained for a wide range of dairy products with fat contents ranging from 0.5 to 83% using pressurized solvent extraction at elevated temperatures and pressure (80-120 degrees C; 10.3 MPa). Extraction performance was sensitive to solvent composition, temperature, and sample matrix. By optimizing solvent mixtures, sample-solvent contact times of 8-10 min were sufficien...

In this chapter, a solvent selection methodology for extractive distillation processes is applied to identify promising ionic liquid (IL) solvents for the following separation cases: methylcyclohexane/toluene, 1-hexene/n-hexane and ethanol/water. Thermodynamic and phase stability analysis are done in order to understand the strong interactions between the solutes and the ionic liquids (solvents...

We employ self-consistent mean-field theory to study the phase behavior and the microstructural sizes of AB diblock copolymers in the presence of a neutral solvent S1 and a slightly B-selective solvent S2. In particular, the effects of copolymer volume fraction phiC, the solvent ratio, and the immiscibility parameter between two solvents chiS1S2, are examined. We find that increasing chiS1S2 no...

Alkyl, most commonly C18, columns are used in reversed-phase HPLC method development. Occasionally additional bonded phases are tested in attempt to optimize the separation. Phenyl bonded phases are an excellent choice to consider when a C18 does not achieve separation. In this work, the unique selectivity of three Agilent ZORBAX phenyl phases is shown and compared against a ZORBAX C18. The phe...

The orientation changes of perpendicular cylindrical microdomains in polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) thin films upon annealing in different solvent vapors were investigated by in situ grazing incidence small-angle X-ray scattering (GISAXS) and ex situ scanning force microscopy (SFM). The swelling of P4VP perpendicular cylinders (C⊥) in chloroform, a non-selective solvent vap...

The temperature dependence of the micelle structures formed by poly(styrene-b-isoprene) (SI) diblock copolymers in the selective solvents diethyl phthalate (DEP) and tetradecane (C14), which are selective for the PS and PI blocks, respectively, have been investigated by small angle neutron scattering (SANS). Two nearly symmetric SI diblock copolymers, one with a perdeuterated PS block and the o...

ZnCl2 hydrate, the main molten salt used in biomass conversion, combined with low concentration HCl is an excellent solvent for the dissolution and hydrolysis of the carbohydrates present in lignocellulosic biomass. The most recalcitrant carbohydrate, cellulose, is dissolved in a residence time less than 1 h under mild conditions without significant degradation. This technology is referred to a...