SIAmate—a compact and modular sequential injection analysis controller

Kullberg, Nils; Vilen, Michael; Sund, Pernilla; Talaslahti, Markus; Sara, Rolf

doi:10.1016/s0039-9140(99)00138-1

Cited by 13 publications

(6 citation statements)

References 2 publications

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“…The experimental setup of the combined Raman and SIA measurements is schematically shown in Figure . A commercial SIAmate analyzer from Arctic Instruments Oy Ab (Turku, Finland) was used in the measurements . A plug of 400 μL of the pH buffer solution (B) was first transferred with the piston pump (P, flow rate: 50 μL/s) to the holding coil (HC, tube diameter, 1 mm) via the multiport valve (MV), followed by 100-μL PANI water dispersion (1:10; 20 μL/s) and 400 μL of the pH buffer solution (50 μL/s).…”

Section: Methodsmentioning

confidence: 99%

Application of Raman Spectroscopy and Sequential Injection Analysis for pH Measurements with Water Dispersion of Polyaniline Nanoparticles

Lindfors

Ivaska

2006

Anal. Chem.

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A novel method for pH measurements between pH 7.5 and 10.4 is reported in this paper. The method combines Raman spectroscopy and the automated sequential injection analysis system (SIA) and makes use of the acid-base properties of a commercially available water dispersion of polyaniline (PANI) nanoparticles with a mean particle size of 46 nm. The useful pH range of the PANI nanoparticles is broader than for conventional acid-base indicators, due to the 1:2 reaction stoichiometry of the proton-ligand complex of the nanoparticles. The pH measurements were conducted with the 633-nm laser excitation wavelength by calculating the difference between the Raman intensities of the primary and reference wavenumbers. In this study, the pH-sensitive CH=CH stretching band at 1422 cm-1 and C-H in-plane bending band of the quinoid form at 1163 cm-1 were chosen as the primary wavenumbers. The presented method is fast and allows pH to be measured with a precision of 0.2 pH unit. The advantage of the proposed method is that the hysteresis effect, which is usually observed for PANI films, can be overcome with the PANI nanoparticles, because a fresh nanoparticle solution is used in each measurement. It should be pointed out, that this work is a fundamental study showing the applicability of Raman spectroscopy in combination with the SIA technique for pH measurements in specific applications, where the conventional glass pH electrode cannot be used.

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Section: Methodsmentioning

confidence: 99%

Application of Raman Spectroscopy and Sequential Injection Analysis for pH Measurements with Water Dispersion of Polyaniline Nanoparticles

Lindfors

Ivaska

2006

Anal. Chem.

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“…The experimental setup of the combined SIA and UV−visible measurements is schematically shown in Figure . A commercial SIAmate analyzer from Arctic Instruments Oy Ab (Turku, Finland) was used in the flow measurements . A plug of 400 μL of pH buffer solution (B) was first transferred with the piston pump (P, flow rate, 50 μL/s) to the holding coil (HC, tube diameter, 1 mm) via the multiport valve (MV), followed by 80 or 100 μL of PANI water dispersion (1:100; 20 μL/s) and 400 μL of pH buffer solution (50 μL/s).…”

Section: Methodsmentioning

confidence: 99%

“…In this paper, a new, simple, and fast photometric method to measure pH with water dispersion of PANI nanoparticles is presented. The pH measurement is done in continuous mode by combining both the automated sequential injection analysis (SIA) system 35,36 and UV-visible spectroscopy or by measuring pH in batch mode using only a fiber-optic light guide. The acid-base equilibrium of the PANI nanoparticles is established entirely in the solution phase.…”

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confidence: 99%

Optical pH Measurements with Water Dispersion of Polyaniline Nanoparticles and Their Redox Sensitivity

2006

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A new method for optical pH and redox measurements with a commercially available water dispersion of polyaniline (PANI) nanoparticles (mean particle size, 46 nm) is presented. The pH measurements are based on the acid−base equilibrium of PANI and were carried out either by combining both the automated sequential injection analysis (SIA) and UV−visible spectrophotometric techniques or with a fiber-optic light guide. In the former case, the detection was done in continuous mode at λ = 800 nm by using the SIA technique for transporting the sample to a flow-through cell, which was placed in the light path of the photometer. With the fiber-optic light guide, the detection was done in batch mode at λ = 400 and 580 nm. In both methods, fresh pH reagent (PANI) solution was used in each measurement, thus overcoming the problem with hysteresis (memory effect), which is usually observed with PANI films. The PANI nanoparticles were characterized with UV−visible spectroscopy in pH buffer solutions between pH 2−12 and a protonation constant of log = 4.4 was calculated from these data. Fast pH measurements can be done between pH 6 and 10.5 depending on the measuring technique. It is possible to determine pH with an accuracy of 0.1 pH unit between pH 8 and 10.5 (RSD, 0.5−2%). Redox transitions typical for PANI films were also observed for water solutions of PANI nanoparticles in the presence of the hexacyanoferrate(II/III) and the iron(II/III) oxalate redox couples. The absorbance at λ = 875 nm is linearly dependent on the logarithm of the concentration ratio (0.1−10) of the iron oxalate redox couple.

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“…After manual pre-treatment, the analysis of electroplating samples and steel standard reference materials gave results that correlated well with those of AAS. Kullberg et al 261 determined chromium(VI) in chromate conversion baths and magnesium in the presence of high nickel concentrations (after masking the nickel with triethylenetetramine) using diphenylcarbazide and Erichrome Blue-Black B as chromogenic reagents, respectively.…”

Section: 7mentioning

confidence: 99%