This paper reports a development of microfluidic devices integrating an ion selective-field effect transistor (ISFET) sensor with a tantalum pentoxide as a sensing surface to detect protons. To attain high sensitivity in flow injection analysis, a novel on-line preconcentration of ionic analytes was demonstrated by integrating a pair of metal electrodes on a microchannel. In our proposed method...

Background: To determine whether in the era of cell-free fetal DNA (cffDNA), first and second trimester maternal serum analytes will be obsolete or whether they have a role in predicting adverse pregnancy outcomes. Methods: Retrospective cohort study using maternal serum analyte results from first trimester and sequential screening tests from 1/2002 to 12/2012. Abnormal serum analytes included ...

In this paper, a new and simple IR sensing device was proposed for the determination of semi-volatile chlorinated aromatic compounds in aqueous solutions. In this sensing device, a 20-mL glass vial was modified and used to analyze aqueous solutions by conventional Fourier-Transform Infrared (FT-IR) spectrometer. An aluminum plate coated with hydrophobic film was placed on the top of the cap of ...

BACKGROUND Blood samples collected in rural and remote areas of Australasia are often exposed to a range of environmental conditions prior to analysis in a laboratory. The aim of this study was to determine analyte stability of venous blood specimens in serum gel tubes exposed to a range of storage temperatures and times prior to centrifugation. METHODS Thirty healthy adult volunteers were en...

The paper presents a novel on-line transient moving chemical reaction boundary method (tMCRBM) for simply but efficiently stacking ionizable analytes in high-salt matrix in capillary zone electrophoresis (CZE). The powerful function and stability of the tMCRBM are elucidated with the ionizable test analytes of L-phenylalanine (Phe) and L-tryptophan (Trp) in the matrix with 85.6-165.6 mM sodium ...

The NIRSystems 6500 spectrophotometer has been used to study analytes in bagasse, shredded cane, direct analysis of cane extracts (DAC), mixed juice, molasses and raw sugar. Analytes included pol, brix, dry solids, moisture, sucrose, glucose, fructose, invert, ethanol, colour, ash and starch. Although Near Infra Red (NIR) is a secondary technique, relying on conventional laboratory procedures f...

in the present work a modified in-tube solid phase microextraction technique followed by gas chromatography-mass spectrometry (gc-ms) has been applied for determination of water odorants. geosmin, 2-methyl isoborneol, 2-isopropyl-3-methoxy pyrazine, 2-isobutyl-3-methoxy pyrazine and 2,4,6-trichloroanisol are of the most important odorants which have been studied. in the described method, analyt...

Electrospray ionization (ESI) generates intact gas-phase ions from analytes in solution for mass spectrometric investigations. ESI can proceed via different mechanisms. Low molecular weight analytes follow the ion evaporation model (IEM), whereas the charged residue model (CRM) applies to large globular species. A chain ejection model (CEM) has been proposed for disordered polymers.

Microextraction techniques, especially dynamic techniques like in-tube extraction (ITEX), can require an extensive method optimization procedure. This work summarizes the experiences from several methods and gives recommendations for the setting of proper extraction conditions to minimize experimental effort. Therefore, the governing parameters of the extraction and injection stages are discuss...

BACKGROUND Preanalytical conditions encountered during collection, processing, and storage of biospecimens may influence laboratory results. The National Children's Study (NCS) is a planned prospective cohort study of 100,000 families to examine the influence of a wide variety of exposures on child health. In developing biospecimen collection, processing, and storage procedures for the NCS, we ...