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A Novel Type of Tri-Colour Light-Emitting-Diode-Based Spectrometric Detector for Low-Budget Flow-Injection Analysis

View Article: PubMed Central

ABSTRACT

In this paper we describe a low-cost spectrometric detector that can be easily assembled in a laboratory for less than €80 with a minimal number of optical components and which has proved sensitive and flexible enough for real-life applications. The starting point for the idea to construct this small, compact low-cost spectrometric detector was the decision to use a tri-colour light-emitting diode (LED) of the red-green-blue (RGB) type as a light source with the objective of achieving some flexibility in the selection of the wavelength (430 nm, 565 nm, 625 nm) but avoiding the use of optical fibres. Due to the dislocation of the emitters of the different coloured light, the tri-colour LED-based detector required an optical geometry that differs from those that are described in literature. The proposed novel geometry, with a coil-type glass flow-through cell with up to four ascending turns, proved useful and fit for the purpose. The simplicity of the device means it requires a minimal number of optical components, i.e., only a tri-colour LED and a photoresistor. In order to make a flow-injection analysis (FIA) with the spectrometric detector even more accessible for those with a limited budget, we additionally describe a low-cost simplified syringe-pump-based FIA set-up (€625), the assembling of which requires no more than basic technical facilities. We used such a set-up to test the performance of the proposed spectrometric detector for flow-injection analyses. The tests proved its suitability for real-life applications. The design procedures are also described.

No MeSH data available.


FIAgrams (left) and calibration line (right) obtained for calibration solutions with hydrogen phosphate concentration extending from 0.1 to 1.3 mg/L.
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f12-sensors-07-00166: FIAgrams (left) and calibration line (right) obtained for calibration solutions with hydrogen phosphate concentration extending from 0.1 to 1.3 mg/L.

Mentions: The equations of the fitted model calculated by the Statgraphics Centurion software were used to predict the slope and intercept of the hydrogen phosphate calibration line under the optimal experimental conditions; the calculated values were 0.167 and 0.0718 respectively. Experiments were performed under the predicted experimental conditions. The peaks and calibration line obtained for the hydrogen phosphate calibration solutions 0.1–1.3 mg/L are presented in Figure 12. The hydrogen phosphate concentration determination with the proposed FIA set-up and time-based colour forming reagent injection with low 25-μL reagent consumption per determination proved possible.


A Novel Type of Tri-Colour Light-Emitting-Diode-Based Spectrometric Detector for Low-Budget Flow-Injection Analysis
FIAgrams (left) and calibration line (right) obtained for calibration solutions with hydrogen phosphate concentration extending from 0.1 to 1.3 mg/L.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756699&req=5

f12-sensors-07-00166: FIAgrams (left) and calibration line (right) obtained for calibration solutions with hydrogen phosphate concentration extending from 0.1 to 1.3 mg/L.
Mentions: The equations of the fitted model calculated by the Statgraphics Centurion software were used to predict the slope and intercept of the hydrogen phosphate calibration line under the optimal experimental conditions; the calculated values were 0.167 and 0.0718 respectively. Experiments were performed under the predicted experimental conditions. The peaks and calibration line obtained for the hydrogen phosphate calibration solutions 0.1–1.3 mg/L are presented in Figure 12. The hydrogen phosphate concentration determination with the proposed FIA set-up and time-based colour forming reagent injection with low 25-μL reagent consumption per determination proved possible.

View Article: PubMed Central

ABSTRACT

In this paper we describe a low-cost spectrometric detector that can be easily assembled in a laboratory for less than €80 with a minimal number of optical components and which has proved sensitive and flexible enough for real-life applications. The starting point for the idea to construct this small, compact low-cost spectrometric detector was the decision to use a tri-colour light-emitting diode (LED) of the red-green-blue (RGB) type as a light source with the objective of achieving some flexibility in the selection of the wavelength (430 nm, 565 nm, 625 nm) but avoiding the use of optical fibres. Due to the dislocation of the emitters of the different coloured light, the tri-colour LED-based detector required an optical geometry that differs from those that are described in literature. The proposed novel geometry, with a coil-type glass flow-through cell with up to four ascending turns, proved useful and fit for the purpose. The simplicity of the device means it requires a minimal number of optical components, i.e., only a tri-colour LED and a photoresistor. In order to make a flow-injection analysis (FIA) with the spectrometric detector even more accessible for those with a limited budget, we additionally describe a low-cost simplified syringe-pump-based FIA set-up (€625), the assembling of which requires no more than basic technical facilities. We used such a set-up to test the performance of the proposed spectrometric detector for flow-injection analyses. The tests proved its suitability for real-life applications. The design procedures are also described.

No MeSH data available.