We report a novel system to analyze atmospheric nitrophenols (NPs). Rain or air sample extracts (1 mL) are preconcentrated on a narrow bore (2 mm) aliphatic anion exchanger. In the absence of strong retention of NPs exhibited by aromatic ion exchangers, retained NPs are eluted as a plug by injection of 100 microL of 0.1 M Na(2)SO(4) on to a short (2 x 50 mm) reverse phase C-18 column packed wit...

A method using liquid chromatography coupled to tandem mass spectrometry is described for the determination of drugs of abuse in oral fluid. The method is able to simultaneously quantify amphetamines (amphetamine, methamphetamine, MDA, MDMA and MDEA), opiates (morphine and codeine), cocaine and benzoylecgonine. Only 200 micro of oral fluid is spent for analysis. The sample preparation is easy a...

Electrospray mass spectrometry (ES-MS) is a powerful tool for analysis of carcinogen-adducted DNA. In this study, we developed a quantitative isotope dilution method for analysis of N-(deoxyguanosine-8-yl)-4-aminobiphenyl (dG-C8-4-ABP), the principal nucleoside adduct derived from enzymatic hydrolysis of 4-aminobiphenyl (4-ABP)-modified DNA. The method used column switching valves to perform on...

The formation of 5-methyl-2'-deoxycytidine (5-MedC) following methylation of the C-5 position of cytosine in genomic DNA provides an epigenetic mechanism for the regulation of gene expression and cellular differentiation. We describe the development of a method using HPLC-ultraviolet (UV) detection for the accurate determination of 5-MedC in DNA. Genomic DNA was obtained from HeLa cells and rat...

These two cases illustrate eight instances of aspiration of fine bore enteral feed. On three occasions the tube remained correctly placed and on five occasions the tube was noted to be in the oropharynx. Fine bore enteral feeding is popular in intensive care units because ofthe high patient acceptability and ease ofmanagement in conjunction with continuous feeding pumps. Severely ill patients, ...

Proteomic samples such as human serum are an extreme challenge to study due to the large dynamic range of the proteins of interest. The proteins in human serum can range from those considered “high-abundance” proteins, present at 2%–50% of the total protein mass (typically the μg/mL–mg/mL range) to those considered tissue biomarkers present in the pg/mL–ng/mL range. Multidimensional separation ...

A tidal bore is a surge of water propagating upstream as the tidal flow turns to rising into an estuary with a tidal range larger than 5 to 6 m and a bathymetry that amplifies the tidal wave. The bore front is a shock characterised by a singularity of the free-surface and pressure and velocity fields. This study aims to characterise the tidal bore propagation and the induced turbulent mixing un...

A simple one-step in situ "click" modification strategy was developed for the preparation of hydrophobic organic monolithic columns for the first time. The column morphology and surface chemistry of the fabricated monolithic columns were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, respectively. The chromatographic ...

This paper presents two high performance liquid chromatographic (HPLC) methods used for the separation and determination of artificial sweeteners aspartame, acesulphame K, sodium saccharin, and sodium cyclamate in beverages and special nutritional products (special food intended for specific population groups). All four compounds are soluble in aqueous solutions and can easily be separated and ...