Advancement of Flow-based Analysis with Alternative Chemical Reactions and New Devices for Environmental and Biological Samples

Sakai, Tadao; Teshima, Norio

doi:10.2116/analsci.24.855

Cited by 11 publications

(4 citation statements)

References 77 publications

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“…6 In this context, sequential injection (SI) analysis is a well-established automatedpretreatment (Auto-Pret) platform, offering great advantages in the automation and miniaturization of the analytical methods. [7][8][9][10][11] Over the last few decades, research in the field of solid phase extraction has focused on the synthesis and study of new sorbent materials with improved characteristics, 12 like co-polymeric beads Oasis HLB, 13,14 carbon nanotubes, [15][16][17] magnetic particles, 6,18 lysine-modified mesoporous silica (Fmoc-SBA-15), 19 polytetrafluoroethylene (PTFE), 20 polyether-etherketone (PEEK), 21 since the selection of the appropriate one is of prime importance for the sensitivity and selectivity of an analytical method. Nobias chelate PA-1, first introduced by Sakamoto et al 22 and Yamamoto et al, 23 is a chelating adsorbent consisting of a hydrophilic methacrylate polymer backbone, which is chemically modified by amino and carboxylic groups.…”

Section: Introductionmentioning

confidence: 99%

Automatic On-line Solid-phase Extraction-Electrothermal Atomic Absorption Spectrometry Exploiting Sequential Injection Analysis for Trace Vanadium, Cadmium and Lead Determination in Human Urine Samples

et al. 2015

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A fully automated sequential injection column preconcentration method for the on-line determination of trace vanadium, cadmium and lead in urine samples was successfully developed, utilizing electrothermal atomic absorption spectrometry (ETAAS). Polyamino-polycarboxylic acid chelating resin (Nobias chelate PA-1) packed into a handmade minicolumn was used as a sorbent material. Effective on-line retention of chelate complexes of analytes was achieved at pH 6.0, while the highest elution effectiveness was observed with 1.0 mol L(-1) HNO3 in the reverse phase. Several analytical parameters, like the sample acidity, concentration and volume of the eluent as well as the loading/elution flow rates, have been studied, regarding the efficiency of the method, providing appropriate conditions for the analysis of real samples. For a 4.5 mL sample volume, the sampling frequency was 27 h(-1). The detection limits were found to be 3.0, 0.06 and 2.0 ng L(-1) for V(V), Cd(II) and Pb(II), respectively, with the relative standard deviations ranging between 1.9 - 3.7%. The accuracy of the proposed method was evaluated by analyzing a certified reference material (Seronorm(TM) trace elements urine) and spiked urine samples.

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Section: Introductionmentioning

confidence: 99%

Automatic On-line Solid-phase Extraction-Electrothermal Atomic Absorption Spectrometry Exploiting Sequential Injection Analysis for Trace Vanadium, Cadmium and Lead Determination in Human Urine Samples

et al. 2015

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“…Sample preparation processes developed in batch mode are usually time consuming and labour excessive, besides tending to consume excessive amounts of reagents and producing large amounts of harmful organic solvents. 9 In order to overcome these drawbacks, flow injection (FI) techniques have been well developed as a tool for automation, speeding up and miniaturization of solution handling during sample preparation. Likewise, improved precision, enrichment factors and limits of detection (LODs) can be ensured.…”

Section: Introductionmentioning

confidence: 99%

An online ionic liquid-based microextraction system coupled to electrothermal atomic absorption spectrometry for cobalt determination in environmental samples and pharmaceutical formulations

Bertón

Wuilloud

2011

Anal. Methods

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“…[1][2][3][4][5][6][7] Silica gel, alumina, activated carbon, and synthetic or natural polymers have found various applications as adsorbents.…”

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Adsorption-Partition Switching of Retention Mechanism in Ice Chromatography with NaCl-doped Water-Ice

Tasaki

Okada

2009

ANAL. SCI.

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Adsorption and partition are the most fundamental phenomena involved in various natural and industrial processes, and, in analytical chemistry, have been utilized for various purposes: e.g. separation, condensation, removal of interferents etc. [1][2][3][4][5][6][7] Silica gel, alumina, activated carbon, and synthetic or natural polymers have found various applications as adsorbents. [1][2][3][4] On the other hand, partition has also long been studied as an essential mechanism in solvent extraction. [5][6][7] Although earlier work of solvent extraction focused on the bulk processes occurring in liquid phases, current methodologies have revealed the important involvements of interfaces in partition phenomena; 8 e.g. interfacial processes determine the kinetics of the entire partition reactions in some cases. However, as far as most of the molecular interactions in condensed phases are concerned, adsorption dominantly occurs on the surface of a solid whereas partition mostly occurs in a liquid phase.The terminology of adsorption and partition is often used for the classification of chromatography, i.e. adsorption chromatography and partition chromatography. 9 Liquid chromatography with silica gel as a stationary phase is a typical example of adsorption chromatography, while reversed-phase chromatography with ODS silica gel is usually considered as partition chromatography. In the latter mode, the retention mechanism is explained on the basis of the assumption that the hydrocarbon layer on the stationary phase surface accommodates a solute in a way similar to the solvation in a bulk solvent. Thus, adsorption and partition mechanisms are clearly distinguished from each other in usual liquid chromatography. Some studies have indicated that the surfaces of an ODS stationary phase show solid-liquid phase transition at a particular temperature; it was detected e.g. by a flection point of a van't Hoff plot. 10 If this consideration were correct, the retention mechanism would also be altered at the phase transition temperature between adsorption and partition. However, such a change actually depends on various factors and occurs over a relatively broad temperature range rather than at a well-defined phase transition temperature. Thus, this is not a real phase transition.The temperature is an important factor affecting chromatographic retention even though the retention relies on a single mechanism. However, if a phase transition occurs, a drastic change in retention is expected. Kanazawa et al. 11 have published a number of papers concerning temperatureresponsive stationary phases. They have utilized polymers showing a temperature-induced change in hydration. An aqueous solution of this polymer gives a well-defined critical temperature, at which its aqueous solution becomes turbid when warmed. This phase transition allows the modification of the hydrophobicity of the stationary phase surface simply by heating a separation column slightly higher than the ambient temperature.We have proposed ice chromatography, in which wa...

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Advancement of Flow-based Analysis with Alternative Chemical Reactions and New Devices for Environmental and Biological Samples

Cited by 11 publications

References 77 publications

Automatic On-line Solid-phase Extraction-Electrothermal Atomic Absorption Spectrometry Exploiting Sequential Injection Analysis for Trace Vanadium, Cadmium and Lead Determination in Human Urine Samples

Automatic On-line Solid-phase Extraction-Electrothermal Atomic Absorption Spectrometry Exploiting Sequential Injection Analysis for Trace Vanadium, Cadmium and Lead Determination in Human Urine Samples

An online ionic liquid-based microextraction system coupled to electrothermal atomic absorption spectrometry for cobalt determination in environmental samples and pharmaceutical formulations

Adsorption-Partition Switching of Retention Mechanism in Ice Chromatography with NaCl-doped Water-Ice

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