Portable Multispectral Colorimeter for Metallic Ion Detection and Classification

Abstract

This work deals with a portable device system applied to detect and classify different metallic ions as proposed and developed, aiming its application for hydrological monitoring systems such as rivers, lakes and groundwater. Considering the system features, a portable colorimetric system was developed by using a multispectral optoelectronic sensor. All the technology of quantification and classification of metallic ions using optoelectronic multispectral sensors was fully integrated in the embedded hardware FPGA ( Field Programmable Gate Array) technology and software based on virtual instrumentation (NI LabView®). The system draws on an indicative colorimeter by using the chromogen reagent of 1-(2-pyridylazo)-2-naphthol (PAN). The results obtained with the signal processing and pattern analysis using the method of the linear discriminant analysis, allows excellent results during detection and classification of Pb(II), Cd(II), Zn(II), Cu(II), Fe(III) and Ni(II) ions, with almost the same level of performance as for those obtained from the Ultravioled and visible (UV-VIS) spectrophotometers of high spectral resolution.

Progress in the design of portable colorimetric chemical sensing devices

“…The devices come with precalibrated settings for specific substances, ensuring accurate and reliable measurements. 38,39 Fig. 1 illustrates the graphical scheme of a portable colorimetric device where the concentration of a chemical substance in an unknown sample solution can be directly monitored from the sample sites.…”

Utilization of data classification in the realization of a surface Plasmon resonance readout system using an FPGA controlled RGB LED light source

“…This approach is able accommodate more sensing mechanisms than single spectral band approach especially in application that have multiple spectral band of interest. [27]. The RGB color light pulses are generated by the FPGA using pulse width modulation (PWM).…”

“…The digital waveforms stored in the FPGA's RAM are generated beforehand and addressed during operation [29]. An arbitrary light waveform may be useful in applications such as in the case of lock-in signal detection [30], fluorescent measurement [27] and laser diode wavelength tuning. In the case of this investigation, the three PWM output configuration was used solely for switching and intensity control purpose.…”

Hierarchical Porous Carbon Electrodes with Sponge-Like Edge Structures for the Sensitive Electrochemical Detection of Heavy Metals

“…Owing to the simple configuration and small size, electrochemical and colorimetric analysis methods have been adopted for on-site heavy metal detection. In addition, these methods facilitate a more sensitive detection of multiple heavy metal ions at a lower cost, as compared to that of the portable XRF spectrometry [ 10 , 11 , 12 ]. Recently, Ying Gan et al reported the successful detection of cadmium at concentrations as low as 1.12 ppb, using a colorimetric method; this concentration is much lower than the EPA standard for cadmium concentration in drinking water [ 13 ].…”