Optical fiber coupled light emitting diode based absorbance detector with a reflective flow cell

Jambunathan, Sivakumar; Dasgupta, Purnendu Κ.; Wolcott, Duane K.; Marshall, Graham D.; Olson, Don C.

doi:10.1016/s0039-9140(99)00132-0

Cited by 45 publications

(18 citation statements)

References 17 publications

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“…A third fiber optic connected the light from the bottom of the LED to a reference photodiode (Ref PD). The detector electronics have been described previously; 31 it is also commercially available (www.globalfia.com).…”

Section: Apparatusmentioning

confidence: 99%

Selective Measurement of Gaseous Hydrogen Peroxide with Light Emitting Diode-Based Liquid-Core Waveguide Absorbance Detector

Dasgupta

2003

ANAL. SCI.

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Atmospheric H2O2 is typically determined by enzymatically mediated fluorogenic reactions that do not discriminate between H2O2 and organic peroxides. Reactions of Ti(IV) with H2O2 has also been the basis of colorimetric measurements of H2O2 but is too insensitive. A more sensitive determination is possible with the Ti(IV)-4-(2-pyridylazo)resorcinol (PAR) complex, however, unreacted PAR must be chromatographically separated. A titanium(IV)-porphyrin complex, oxo [5,10,15,20-tetra(4-pyridyl)porphyrinato]titanium(IV) [TiO(tpypH4) 4+ ], (TiTPyP) was introduced for the measurement of aqueous H2O2. In this paper, we show that TiTPyP can be used for measuring H2O2(g), it does not respond to CH3HO2. With a proper membrane collector, practically there is no interference from concurrently present gaseous SO2 and O3. The approach permits a S/N = 3 limit of detection (LOD) of 26 pptv with a 50 mm path liquid core waveguide (LCW) absorbance detector and a light emitting diode based light source. This is adequate for real atmospheric measurements.

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Section: Apparatusmentioning

confidence: 99%

Selective Measurement of Gaseous Hydrogen Peroxide with Light Emitting Diode-Based Liquid-Core Waveguide Absorbance Detector

Dasgupta

2003

ANAL. SCI.

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“…[3][4][5][6] Small size, low cost, high stability of the radiation beam, and long lifetime are the main features of LEDs which explains its widespread use in different analytical procedures. [7][8][9] The availability of LEDs with wavelengths ranging from ultraviolet (l ca.…”

Section: Introductionmentioning

confidence: 99%

Automatic photometric titration procedure based on multicommutation and flow-batch approaches employing a photometer based on twin LEDs

Silva¹,

Crispino²,

Reis³

2010

J. Braz. Chem. Soc.

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Neste trabalho, é descrito um fotômetro de baixo custo baseado em um par de LEDs idênticos, empregando um, como fonte de luz e o outro como fotodetector. O equipamento, incluindo o fotômetro e o módulo de análises, foi projetado para implementar um procedimento de titulação automático empregando o processo de multicomutação por injeção em fluxo (MCFIA). O sistema proposto dispunha de meios para realizar a titulação fotométrica sem a necessidade de empregar curva analítica. A utilidade foi comprovada analisando amostras de vinagre e sucos de limão, laranja, abacaxi, maracujá e cajú. A exatidão foi verificada comparando os resultados com outros, obtidos empregando procedimento manual, e não foi observada diferença significativa no nível de confiança de 95%. Amostras com diferentes concentrações de ácido, tais como suco de limão (1.084,73 mmol L ) foram tituladas usando a mesma solução titulante, e sem modificação do sistema de titulação.In this work, a reliable and inexpensive photometer based on twin LEDs assembled as a radiation source and as a photodetector is described. The setup including the photometer and flow system module was designed to implement an automated titration procedure employing the multicommuted flow injection analysis (MCFIA) process. The proposed system was able to carry out photometric titration without using analytical curve to achieve the sample concentration. Its usefulness was proven by analyzing vinegar and lemon, orange, pineapple, maracock, and acajou juices. Accuracy was accessed comparing results with those obtained employing a manual procedure and no significant difference was observed at 95% confidence level. Samples presenting different acid concentrations such as lemon juice (1084.73 mmol L -1 ) and pineapple juice (14.42 mmol L -1 ) could be titrated using the same titration solution without any modification of the titrating setup.

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“…LED's have also been commonly used in detection systems for chromatography, [5 -7] flow injection analysis, [8] and its high precision for absorption and fluorescence measurements [9 -12] has been demonstrated for the visible and NIR regions. In this paper, a mini-photometer, consisting of only two light emitting diodes (LEDs), a cell, and a photodiode was developed.…”

Section: Introductionmentioning

confidence: 99%

Double‐LED Source for a Portable Photometer to Determine Iodine and Formaldehyde In Situ

Zou

Wang

et al. 2007

Instrumentation Science & Technology

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An example of using an LED (light emitting diode) as light source to miniaturize the conventional large spectrophotometer is demonstrated by the development of a portable photometer with two LEDs as light source and its application to determination of iodine in edible salt and formaldehyde in the atmosphere, in situ. High speed, good precision, and low cost distinguished the procedure from other methods. The RSD (n ¼ 8) for measurement of iodine in edible salt varied from 0.7% to 1.5%, and the RE (n ¼ 3) for formaldehyde measurement varied from 0.8% to 4.4%. The analytical results obtained were in good agreement with those obtained with a conventional spectrophotometer. The portable instrumentation was demonstrated to be suitable for the quality control of edible salt and ambient air, in-situ.

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Optical fiber coupled light emitting diode based absorbance detector with a reflective flow cell

Cited by 45 publications

References 17 publications

Selective Measurement of Gaseous Hydrogen Peroxide with Light Emitting Diode-Based Liquid-Core Waveguide Absorbance Detector

Selective Measurement of Gaseous Hydrogen Peroxide with Light Emitting Diode-Based Liquid-Core Waveguide Absorbance Detector

Automatic photometric titration procedure based on multicommutation and flow-batch approaches employing a photometer based on twin LEDs

Double‐LED Source for a Portable Photometer to Determine Iodine and Formaldehyde In Situ

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