نتایج جستجو برای: preconcentration

تعداد نتایج: 2262  

2001
Ewa Bulska

Atomic spectrometry and electrochemistry are usually recognized as independent analytical tools used for different purposes. Here, a brief review is given of the advantages of using electrochemistry in the various fields of atomic spectrometry techniques. In the first part, the application of electrochemical preconcentration before the atomic spectrometry will be addressed and exemplified. Elec...

2014
Szymon Dziomba Adrian Bekasiewicz Adam Prahl Tomasz Bączek Piotr Kowalski

Derivatization is a frequently used sample preparation procedure applicable to the enhancement of analyte detection sensitivity. Amino acids mostly require derivatization prior to electrophoretic or chromatographic analysis, especially if spectrophotometric detection is used. This study presents an on-line preconcentration technique for derivatized amino acids. The sensitivity of the method was...

Journal: :Journal of chromatography. A 2006
Maojun Gong Kenneth R Wehmeyer Patrick A Limbach William R Heineman

On-line sample preconcentration of oligonucleotides with a new sweeping carrier was developed by using dodecyltrimethylammonium bromide (DTAB) below the critical micelle concentration (CMC). The sweeping results with DTAB below and above the CMC were compared. The use of DTAB below the CMC benefits the preconcentration of the oligonucleotides, while the use of DTAB above the CMC is good for hyd...

Journal: :Talanta 2003
Winai Ouangpipat Tapparath Lelasattarathkul Churairat Dongduen Saisunee Liawruangrath

The present work describes the development and application of a carbon paste electrode modified by treated-Pennisetum setosum for the determination of lead(II) by anodic stripping differential pulse voltammetry. Most experiments were performed using the preconcentration/voltammetry/regeneration scheme. The resulting modified electrode offers a preferential uptake of lead(II) from solutions. Ope...

2007
Ying-Chih Wang Vincent H. Liu Jongyoon Han

This paper describes a microfluidic immunoassay device with integrated preconcentration system, enabling the detection of various analytes (proteins) at low target concentrations with faster binding kinetics. It not only complements recent advances of novel immuno-biosensors, but also can be used to further enhance the most novel and advanced immuno-biosensor systems developed. The work has dem...

2005
F. A. Silva I. L. de Alcântara P. S. Roldan C. C. F. Padilha A. B. de Araújo J. P. S. Valente A. O. Florentino P. M. Padilha

This paper discusses a rapid and sensitive method developed to determine trace levels of mercury in natural water samples by cold vapor atomic absorption spectrometry using a preconcentration system composed by mini-column packed with 100 mg of 2-aminothiazol modified silica gel (SiAT) coupled on-line with the spectrometer’s cold vapor generator system. The optimum preconcentration conditions a...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2007
Maria C Yebra-Biurrun Sheila Cancela-Pérez

A rapid and sensitive method has been proposed for the determination of chromium and cobalt in seafood samples by flame atomic absorption spectrometry combined with a dynamic ultrasound-assisted acid extraction and an on-line minicolumn preconcentration. The use of diluted nitric acid as extractant in a continuous mode at a flow rate of 3.5 mL min(-1) and room temperature was sufficient for qua...

Journal: :Lab on a chip 2017
Cheonjung Kim Yong Kyoung Yoo Sung Il Han Junwoo Lee Dohwan Lee Kyungjae Lee Kyo Seon Hwang Kyu Hyoung Lee Seok Chung Jeong Hoon Lee

Paper-based analytical devices (e.g. lateral flow assays) are highly advantageous as portable diagnostic systems owing to their low costs and ease of use. Because of their low sensitivity and detection limits for biomolecules, these devices have several limitations in applications for real-field diagnosis. Here, we demonstrate a paper-based preconcentration enhanced lateral flow assay using a c...

2016
Eveliina Repo Jolanta K. Warchoł Mika Sillanpää

This study focuses on the adsorption and preconcentration of various metals by silica gel surfaces modified with aminopolycarboxylic acids namely ethylenediaminetetraacetic acid or diethylenetriamine-pentaacetic acid. The adsorption performance of the studied materials was determined in mixed metal solutions and the adsorption isotherm studies were conducted for cobalt, nickel, cadmium, and lea...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2006
Kazuhiko Takeda Shinya Katoh Nobutake Nakatani Hiroshi Sakugawa

The aim of this research was to develop a simple procedure for a highly sensitive determination of low-molecular-weight (LMW) carbonyl compounds in drinking water and natural water. We employed a preconcentration HPLC system with 2,4-dinitrophenylhydrazine (DNPH) for the determination of LMW carbonyl compounds. A C-18 reverse-phase preconcentration column was used instead of a sample loop at th...

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