Determination of aqueous ozone for potable water treatment applications by chemiluminescence flow-injection analysis. A feasibility study

Chung, Hye‐Kyung; Bellamy, Harvey S.; Dasgupta, Purnendu Κ.

doi:10.1016/0039-9140(92)80066-m

Cited by 16 publications

(7 citation statements)

References 10 publications

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“…[1][2][3][4][5][6][7] There are many emerging applications for UV LEDs in spectroscopy, chemical and biological analysis, and water and food treatment. [8][9][10][11] LEDs are preferred for these applications because they are small, power efficient, contain no hazardous materials, are highly resistant to shock, and have very long lifetimes. High power UV LEDs are considered as replacements for conventional light sources for many industrial and commercial purposes, at a potentially enormous world-wide energy savings.…”

Section: Introductionmentioning

confidence: 99%

Digital Alloys of AlN/AlGaN for Deep UV Light Emitting Diodes

Nikishin

Holtz

Temkin

2005

Jpn. J. Appl. Phys.

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We report a systematic study of the optical and electrical properties of deep ultraviolet light emitting diodes based on digital alloy structures of AlN/Al0.08Ga0.92N grown by gas source molecular beam epitaxy with ammonia. Digital alloys are formed by short period superlattices consisting of Al0.08Ga0.92N wells, 0.50 or 0.75 nm thick, and AlN barriers, 0.75 to 1.5 nm thick. For digital alloys with effective bandgap of 5.1 eV, average AlN composition 72%, we obtain room temperature electron concentrations up to 1×1019 cm-3 and resistivity of 0.005 Ω·cm and hole concentrations of 1×1018 cm-3 with resistivity of 6 Ω·cm. Light emitting diodes based on digital alloys are demonstrated operating in the range of 250 to 290 nm.

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Section: Introductionmentioning

confidence: 99%

Digital Alloys of AlN/AlGaN for Deep UV Light Emitting Diodes

Nikishin

Holtz

Temkin

2005

Jpn. J. Appl. Phys.

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“…Generally, the CL methods based on organic dyes are highly specific for ozone; ,,,,, other common oxidizing atmospheric trace gases, such as NO 2 , H 2 O 2 , and peroxyacetyl nitrate (PAN), do not interfere with the determination. We had ourselves determined that alkaline CA does not produce detectable CL with aqueous H 2 O 2 or Cl 2 (as OCl - ) even at a relatively high level of 10 mg/L (0.3 mM H 2 O 2 ) . During this work, we studied potential interference of gaseous NO 2 , up to 137 ppbv in concentration, under conditions identical to that used for measuring O 3 .…”

Section: Resultsmentioning

confidence: 99%

“…In the past, we had investigated the relative CL sensitivities of aqueous solutions of a number of fluorescent compounds for the measurement of dissolved O 3 , the general hypothesis being that the energy released in the oxidation may be transferred to another intact molecule of the fluor (present in much larger excess) and which then luminesces. Chromotropic acid (CA) was the most sensitive, about twice the nearest competitor, Rhodamine B.…”

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confidence: 99%

Chemiluminometric Measurement of Atmospheric Ozone with Photoactivated Chromotropic Acid

Takayanagi

Dasgupta

et al. 2003

Anal. Chem.

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A highly sensitive, robust, fast, affordable measurement system based on interfacial gas-liquid chemiluminescence (CL) on a wetted transparent screen directly on top of a miniature photomultiplier tube provides the basis of an attractive method for ozone (O(3)). Alkaline chromotropic acid (CA, 4,5-dihydroxynaphthalene-2,7-disulfonic acid) chemiluminesces upon exposure to ozone. No light emission is observed from exposure of alkaline CA to NO(2) or H(2)O(2). However, response to ozone is highly dependent on the age and storage condition of the CA solution. As such, quantitative analysis will require frequent calibration, and the method will not be attractive. We have discovered that photoactivation plays the key role in producing (a) compound(s) from chromotropic acid that appear(s) to be the primary agent(s) responsible for the CL reaction with O(3). We thus devised a method wherein a flowing solution of CA (that is stable in neutral/acidic solutions) is rendered alkaline and then exposed for a few seconds on-line to UV radiation. The solution then reacts with ozone on a screen consisting of an "invisible" nylon stocking that provides for low liquid residence time and high light throughput and results in an LOD of 40 pptv, a determination range at least up to 230 ppbv, and 10-90% and 90-10% response times of 130 and 80 ms, respectively. Intra- and interday repeatabilities at the same concentration were 0.32 and 3.8% in relative standard deviation. On the basis of aging, CL, chromatography, and chromatography-mass spectrometry studies, we suggest that the primary CL-active species are likely dimeric semiquinone species derived from CA by a series of radical reactions.

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“…Spectrophotometric [204] and chemiluminescence based [205] methods for the determination of ozone have been reported recently.…”

Section: Gasesmentioning

confidence: 99%

Advances in Flow Analysis – Instrumentation and its Application in Environmental Analysis

Berman¹

1995

Quality Assurance in Environmental Monitoring

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Determination of aqueous ozone for potable water treatment applications by chemiluminescence flow-injection analysis. A feasibility study

Cited by 16 publications

References 10 publications

Digital Alloys of AlN/AlGaN for Deep UV Light Emitting Diodes

Digital Alloys of AlN/AlGaN for Deep UV Light Emitting Diodes

Chemiluminometric Measurement of Atmospheric Ozone with Photoactivated Chromotropic Acid

Advances in Flow Analysis – Instrumentation and its Application in Environmental Analysis

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