Showing papers by "Purnendu K. Dasgupta published in 1985"
TL;DR: Kuntz, R. A.
Abstract: Kuntz, R.; Lonneman, W. A.; Namie, G.; Hull, L. A. Anal. Let t . 1980, 13, 1409-1415. Fed. Regist. 1979, 44, 233. Cares, J. W. Am. Ind. Hyg. Assoc. J. 1968, 29, 405-410. Pitts, J. N., Jr.; Sanhueza, E.; Atkinson, R.; Carter, W. P. L.; Winer, A. M.; Harris, G. W.; Plum, C. W. Int. J. Chem. Kinet. 1984,16, 919-939. Shepson, P. B.; Edney, E. 0.; Corse, E. W. J. Phys. Chem. 1984,88,4122-4126. Killus, J. P.; Whitten, G. Z. Atmos. Environ. 1982, 16, 1973-1988. Leone, J. A.; Seinfeld, J. H. Int. J . Chem. Kinet. 1984,16, 159-193. Haworth, S.; Lawlor, T.; Mortelmans, K.; Speck, W.; Zeiger, E. Environ. Mutagen. 1983, Suppl. 1 , 3-142. Environ Health Perspect. 1982, 43, 139-168. Kleindienst, T. E.; Shepson, P. B.; Edney, E. 0.; Claxton, L. D., submitted for publication in Mutat. Res.
73 citations
TL;DR: In this article, the concept of nested loop valve system was introduced for differential flow analysis of aqueous H/sub 2/O/Sub 2/ and organic peroxides, where one injection valve is inserted within the loop of another.
Abstract: The novel concept of a nested loop valve system wherein one injection valve is inserted within the loop of another has some unique benefits. This is demonstrated for part-per-billion level differential flow injection analysis of aqueous H/sub 2/O/sub 2/ and organic peroxides. 15 references, 3 figures.
50 citations
TL;DR: In this paper, a fluorimetric flow-injection procedure with a single reagent solution containing p-hydroxyphenylacetic acid, peroxidase and ammonia was proposed.
43 citations
TL;DR: In this article, the authors consider polytetrafluoroethylene, polyacetate d'ethyl vinyle, polyperfluorosulfonate, polyethylene and polypropylene.
Abstract: Etude sur du polytetrafluoroethylene, polyacetate d'ethyl vinyle et polyperfluorosulfonate. Influence de la taille et de la charge de l'ion
43 citations
TL;DR: In this paper, a dual membrane annular helical configuration was shown to be a highly efficient low dispersion suppressor for ion chromatography, which contained one filament-filled membrane tube inserted inside another closely fitting membrane tube of the same type.
Abstract: A dual membrane annular helical configuration is shown to be a highly efficient low dispersion suppressor for ion chromatography. The device contains one filament-filled membrane tube inserted inside another closely fitting membrane tube of the same type. The dual membrane assembly is coiled as a small diameter helix, the shape being retained by the filament. The column effluent flows in the annular space between the two membranes; regenerant flows through two separate channels, inside the inner membrane and through a jacket which surrounds the entire device. Compared to simple filament-filled membrane helices, these devices exhibit a substantially larger available membrane surface area per unit dispersion of an injected band. 20 references, 3 tables, 2 figures.
21 citations
TL;DR: Sub-part-per-billion levels of aqueous hydrogen peroxide have been determined with a flow injection analysis system employing a single bead string reactor composed of horseradish peroxidase covalently bound to an animated macroporous polymeric adsorbent with glutaraldehyde and a passive cation exchange membrane reactor to alter pH.
Abstract: Flow Injection Analysis of Trace Hydrogen Peroxide Using an Immobilized Enzyme Reactor
Sub-part-per-billion levels of aqueous hydrogen peroxide have been determined with a flow injection analysis system employing a single bead string reactor composed of horseradish peroxidase covalently bound to an animated macroporous polymeric adsorbent with glutaraldehyde and a passive cation exchange membrane reactor to alter pH. The chemistry relies on the peroxidase mediated oxidation of nonfluorescentp-hydroxyphenylacetate to its fluorescent dimer. The advantage of the system includes rapid throughout rates (40 samples/h), excellent detection limits (0.3 ppb H2O2) and large dynamic range of linear response (1 ppb-1 ppm). However, the immobilized enzyme is not useful for the analysis of organic peroxides which act as inhibitors.
11 citations
TL;DR: In this article, peak width measurement is employed to determine strong acid or base concentrations by injection into an aqueous indicator flowstream, and investigated parameters include concentration and pK of the indicator, sample volume, carrier flow rate, viscosity of the carrier stream and the diffusion coefficient of the analyte.
Abstract: Studies on Peak Width Measurement-Based FIA Acid-Base Determinations
Peak width measurement is employed to determine strong acid or base concentrations by injection into an aqueous indicator flowstream. Investigated parameters include concentration and pK of the indicator, dimensions and nature of the dispersion tube, signal level employed for peak width measurement, sample volume, carrier flow rate, viscosity of the carrier stream and the diffusion coefficient of the analyte.
11 citations
10 citations
TL;DR: In this paper, peak width measurement flow injection analysis with Potentiometric, Conductometric, Fluorometric, and Spectrophotometric detection is presented. But the method is not suitable for high-dimensional data.
Abstract: Determination of Acids, Bases, Metal Ions and Redox Species by Peak Width Measurement Flow Injection Analysis with Potentiometric, Conductometric, Fluorometric and Spectrophotometric Detection
Conductometric and potentiometric detection for acids/bases, fluorometric detection for Al3+ (aqueous morin carrier), spectrophotometric detection for Fe3+ (KSCN carrier), for H+ (IO3- + I-carrier), for Fe2+ (K3[Fe(CN)6] carrier), for Cu2+ (pyrocatechol violet carrier), for H2O2 (I− carrier) and for Na2S2O3 (I3- carrier) have been employed to investigate the peak width measurement FIA method. Calibration plots over a large concentration range may be constructed by means of a few dispersion measurements, yielding excellent precision.
8 citations
Journal Article•
7 citations
TL;DR: The dibarium salt of beryllon II, 2-(8-hydroxy-3-6-disulfo-1-naphthylazo)-1,8-dihydroxynaphthalene-3,6- Disulfonic acid is the basis of a sensitive Spectrophotometric procedure for determining trace sulfate through liberation of the dye in a 80% 2-propanol medium at an apparent pH of 4.3.
Abstract: The dibarium salt of beryllon II, 2-(8-hydroxy-3,6-disulfo-1-naphthylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid is the basis of a sensitive (LOD 0.14 ppm) convenient Spectrophotometric procedure for determining trace sulfate through liberation of the dye in a 80% 2-propanol medium at an apparent pH of 4.3. The interferences are negligible and good agreement with ion Chromatographie results are demonstrated for environmental samples.