Development of a mobile sensing system forin situwater analysis based on solid-phase extraction–reflection spectroscopy

Abstract

Methods for real-time in situ analysis are needed for the monitoring and detection of pollutants and nutrients in water bodies. In situ instruments reduce the analysis time and decrease the chance of contamination or altering of the sample if taken to the laboratory. For this purpose, a mobile total analysis system is being developed for real-time environmental monitoring. The sensing platform, based on either an autonomous underwater vehicle or remotely operated vehicle, consists of an integrated flow-through channel with a chemically sensitive strip on one side of the channel and an optoelectronic detector opposite the strip. The strip contains an analyte-specific reagent that changes colour upon reaction with the analyte of interest introduced through the flow channel. In determining the feasibility of the design, the detection of copper ions was used as the case study. The interpretation strategy, referencing and calibration from the lab experiments including the effects of flow are shown.

Evaluation of reagentless pH modification for in situ ocean analysis: determination of dissolved inorganic carbon using mass spectrometry

“…[1] Long-term monitoring can capture diurnal, seasonal, and annual trends, thereby benefiting studies of global change, including ocean acidification. [2] Although reagentless sensors for in-situ oceanographic analysis are available for some types of measurements, [3][4][5][6] many analytical procedures incorporate sequential chemical additions to induce analytical transductions. While some reagents are used exclusively to quantify a single type of analyte (e.g., ferrozine in iron measurements), many procedures require acid or base additions to accurately adjust solution pH as an essential component of an analytical protocol.…”

Sensitive determination of trace mercury by UV–visible diffuse reflectance spectroscopy after complexation and membrane filtration-enrichment

“…In recent years, colorimetric solid phase extraction (C-SPE) has been utilized, which is based on the extraction of analytes onto a proper support loaded with a colorimetric reagent and then quantified directly on the solid support surface using reflectance spectroscopy [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. The main advantage of C-SPE is that the elution step of SPE can be completely eliminated.…”

Spectrometric Determination of the Refractive Index of Optical Wave Guiding Materials Used in Lab-on-a-Chip Applications

“…The development of total analysis lab-on-a-chip systems has experienced a fast growth during the last 30 years. [1][2][3][4][5][6] In these applications, optical sensing techniques are preferred due to their minimally invasive nature, their virtually instantaneous response, and the large variety of low-cost, small light sources and detectors available. Glasses and polymeric materials have been extensively used to fabricate integrated micro-total analysis systems.…”

“…Due to the ease of processing, which allows for micro fabrication outside a clean-room environment, glasses and polymers have been widely used to conform micro-fluidic elements and/or to fabricate channels that host optical fibers. [3][4][5][6] In some cases, glasses and plastics readily lend themselves to fabrication of optically functional elements, enabling their incorporation into sensing devices, facilitating the fabrication of total lab-on-a-chip devices. [7][8][9] The wide variety of transparent materials that can potentially be used for creating micro-optical devices has created the need for measurement systems that can optically characterize them.…”