Current Analytical Chemistry - Volume 9, Issue 2, 2013

Amyloid structures accumulate and propagate through self-assembly of partially folded proteins and peptides, resulting in a range of disease states. Key to understanding amyloid disease is the characterisation of the often toxic oligomeric species formed during the early stages of fibril assembly. Electrospray ionisation- ion mobility spectrometry - mass spectrometry (ESI-IMS-MS) has emerged as a powerful tool to invest Read More

Intrinsically disordered proteins do not adopt well-defined native structures and therefore present an intriguing challenge in terms of structural elucidation as they are relatively inaccessible to traditional approaches such as NMR and X-ray crystallography. Many members of this important group of proteins have a distinct biological function and frequently undergo a conformational change on binding to their physiological ta Read More

Field asymmetric waveform ion mobility spectrometry (FAIMS) is a gas-phase atmospheric pressure separation technique that exploits the difference in the mobility of an ion in alternating low and high electric fields applied between two closely spaced electrodes. FAIMS has the potential to simplify mass spectra by separating complex mixtures of ions, including isobaric ions, prior to mass spectral detection. It is a techniqu Read More

The use of gas-phase ion mobility separation in LC-MS based bottom-up proteomic experiments is described. A data-independent acquisition approach was employed in combination with one and two dimensional reversed phase liquid chromatography separations. The ion mobility component in the acquisition schema affords additional acquisition specificity and improved peptide resolution in terms of system peak Read More

Hypoxia is a common feature observed in solid tumours. It is a target of interest in oncology as it has been found to be closely associated with tumour progression, metastasis and aggressiveness and confers resistance to a variety of chemotherapeutic agents as well as radiotherapy. AQ4N, also known as banoxatrone or 1,4-bis-[2-(dimethylamino-Noxide) ethyl]amino-5,8-dihydroxyanthracene-9,10-dione is a very promising bi Read More

A metallomic analytical approach based on the use of size exclusion chromatography (Superdex-75 and Superdex TM-Peptide) coupled to ICP-MS has been used to obtain metal profiles related to metallobiomolecules overexpression or inhibition in mice caused by contamination. The method is complemented with a second chromatographic dimension (anion and cation exchange chromatography) for species purification and isol Read More

Organic germanium compounds, such as bis-beta-carboxyethylgermanium sesquioxide (“Ge-132”), have attained widespread distribution – particularly in self-medication – and are applied as tonics due to their presumed anticancer activities. In general, the toxicity of this particular organo-germanium compound is low. In contrast to this, acute and chronic toxic effects of inorganic germanium dioxide (GeO2) have be Read More

Recently, the scientific interest for greener analytical methods, has led to the development of novel miniaturized liquid phase microextraction (LPME) methodologies resulting in a minimum amount of organic solvent used, along with fast and economical procedures. Sample preparation is the most time-consuming and polluting step in any analytical method. This review aims to provide an overview of the advances in all the Read More

In this work, the capability of a hybrid tandem technique of LCMS-IT-TOF was examined for speciation of tripropyltin (TPrT), tributyltin (TBT), tripentyltin (TPeT) and triphenyltin (TPhT) and a relatively fast and accurate method was developed for their determination in aqueous solutions. In this context, several chromatographic parameters were studied such as chromatographic column, mobile phase, flow rate and gradient Read More

The aim of this study was to compare two different widely-used methods for the determination of hexavalent chromium (Cr(VI)) in water samples by Electrothermal Atomic Absorption Spectrometry (ETAAS). Both methods are based on the complexation - reaction of Cr(VI) with an organic complexation reagent, which is then extracted and preconcentrated in organic solvent. In the first method, ammonium pyrrolidine dithio Read More

A sequential-injection hydride-generation atomic absorption spectrometry (SIA-HG-AAS) system for the determination of trace levels of selenium was designed and characterised. The system included on-line pre-reduction from Se(VI) to Se(IV) and used NaBH4 as reagent for the generation of the hydride. The operation of the system was optimised regarding the main operating variables by means of appropriate experimental d Read More

We demonstrate the electrochemical pretreatment of carbon fiber microelectrodes (CFEs) based on the sinusoidal- wave potential cycling (50 Hz) of CFEs prior to amperometric analysis. The surface modification and morphology of CFEs after pretreatment was studied using Raman spectroscopy and scanning electron microscopy. The pretreated CFEs were extensively tested for sensing of bioactive compounds (dopa Read More

Hydrogen sulphide (H2S) was traditionally recognized as a pungent toxic gas, but this view has now been revised to include its role as an endogenously produced signaling molecule in mammalian cells, affecting various physiological and pathophysiological processes. Endogenously produced H2S in tissues and blood is reported to be lower than 15 nmol/L [1], which requires sample pre-concentration step and sensitiv Read More

In this study, transition metals (Cu(II), Co(II), Ni(II), Fe(III) and Ru(III)), complexes of Schiff base derived from (6R,7R,Z)-7-(2-(2-aminothiazol-4-yl)-2-(2-carboxypropan-2-yloxyimino)acetamido)-8-oxo-3-(pyridinium— ylmethyl)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylate, Ceftazidime; CFZ) and p-dimethylaminobenzaldehyde (DAB) were prepared and characterized by the analytical and spectroscopic methods. The analytical Read More