A mixed-mode solid-phase extraction procedure was developed for the isolation and purification of acidic compounds from complex biological matrices. Urine samples were spiked with several acidic drugs and diluted in ammonium acetate buffer. Isolute HAX columns (a mixed-mode phase consisting of both hydrophobic and ion-exchange ligands) were conditioned with methanol and ammonium acetate prior t...

ammonium ions wastewater pollution has become one of the most serious environmental problems today. the treatment of ammonium ions is a special concern due to their recalcitrance and persistence in the environment. in recent years, various methods for ammonium ion removal from wastewater have been extensively studied. this paper reviews the current methods that have been used to treat ammonium ...

Cobalt(II)-M-hexacyanoferrate(II), M = K, NH4, Cs, as synthetic sorbents have ion exchange properties selective for monovalent cations. They show a higher selectivity for the ions with larger crystal radius if the sorption takes place in dilute solutions, whereas in concentrated sulutions the selectivity sequence is reversed. The phenomenon is attributed to the differences in physico-chemical p...

Results from ion mobility studies of tryptic peptides suggest that, in some cases, the gas-phase structures can be related to the solution-phase structure of the parent protein. The interpretation of ion mobility measurements is supported by results from molecular modeling and H/D exchange experiments on the same peptides. This study clearly illustrates the utility of IM-MS for screening comple...

Peptide mixtures, arising from such diverse sources as tissue extracts, urine or proteolysis, are usually fractionated and characterized by a combination of ion-exchange chromatography, gel-exclusion chromatography and/or electrophoresis. Appropriate combinations of these methods will normally yield a homogeneous product, but their costs, detection limits, analyses times and yields vary. The re...

The fields of metabolomics and metabonomics attempt to phenotype and quantify the vast array of metabolites present in biological samples. Reversed-phase liquid chromatography (LC) coupled with mass spectrometry (MS) is a valuable tool in the separation and identification of these compounds. Reversed-phase HPLC techniques cover a wide range of compounds. However, ionic and polar compounds such ...

Monosulfoaluminate (Ca₄Al₂(SO₄)(OH)12∙6H₂O) plays an important role in anion binding in Portland cement by exchanging its original interlayer ions (SO₄2- and OH-) with chloride ions. In this study, scanning transmission X-ray microscope (STXM), X-ray absorption near edge structure (XANES) spectroscopy, and X-ray diffraction (XRD) were used to investigate the phase change of monosulfoaluminate d...

INTRODUCTION Trifluoroacetic acid (TFA) is commonly used in the manufacturing process to release synthesized peptides from solid-phase resins. TFA or acetate is also used during reversed-phase HPLC purification of peptides. TFA is manufactured using acetate and fluoride as precursors, and residual levels of these compounds may be present whenever TFA is used. Residual TFA, fluoride, and, to a m...

in this study, aniline-formaldehyde polymer was synthesized and then modified with extra aniline as cross-linker in the presence and absence of ni(ii) as the template to produce ion imprinted poly(aniline-formaldehyde) (iipaf) and non imprinted poly(aniline-formaldehyde)(nipaf) the iipaf was subjected to adsorption, preconcentration and determination of ni(ii) ion in environmental samples. the ...

Background: Due to multiple roles of albumin in the body, injection of its medicinal product as one of the therapeutic or management strategies under conditions such as severe bleeding, burns, liver failure, and neonatal hemolytic diseases is on the physicians' agenda. Considering that albumin is the most abundant plasma protein, designing an appropriate method to purify it is highly important....