Development of an In Situ Analyzer Based on Sequential Injection Analysis and Liquid Waveguide Capillary Flow Cell for the Determination of Dissolved Reactive Phosphorus in Natural Waters

Abstract

This study presents an innovative technique for the in situ analysis of aquatic biochemical elements detected through wet chemical processes. A new compact in situ phosphate analyzer based on sequential injection analysis, liquid waveguide capillary flow cell and spectrophotometry was developed, and a safe and modular electronics-chemical separation mechanical structure was designed. The sequential injection system of this analyzer was optimized, and the major functions of this analyzer were studied and estimated. With a 10 cm liquid waveguide capillary flow cell and a 6.3 min time cost of detection, the analyzer reaches a detection limit of 1.4 μg·L−1 (≈14.7 nM, [PO43−]) and a consumption of 23 μL at most for each reagent. This analyzer was operated in situ and online during two scientific research cruises in the Pearl River Estuary and northern South China Sea. The advantages of this analyzer include its simple versatile manifold, full automation, low chemical consumption and electronics-chemical separate safe structure. Long-term in situ performance of this analyzer will be validated in the future.

Industry Partnership: Lab on Chip Chemical Sensor Technology for Ocean Observing

“…Because of the superior metrology performance of reagent based analytical methods (Waterbury et al, 1996;Patey et al, 2008Patey et al, , 2010Ma et al, 2014a;Nagul et al, 2015;Birchill et al, 2019;Takeshita et al, 2020), numerous sensors and analytical systems have been developed employing these techniques. This includes in situ deployed systems for Nitrate (Jannasch et al, 1994;David et al, 1998;Steimle et al, 2002;Adornato et al, 2007;Vuillemin et al, 2009;Yaqoob et al, 2012;Bodini et al, 2015), Phosphate (Adornato et al, 2007;Barnard et al, 2009;Moscetta et al, 2009;Ma et al, 2014b;Bodini et al, 2015;Yang et al, 2020), Iron (Chapin et al, 2002;Johnson et al, 2007;Huang et al, 2012;Meyer et al, 2012), and pH (Waterbury et al, 1996;Bellerby et al, 2002;Martz et al, 2003;Liu et al, 2006;Nakano et al, 2006;Wang et al, 2007Wang et al, , 2015Seidel et al, 2008;Assmann et al, 2011;Spaulding et al, 2011;Lai et al, 2018). Some of these systems are commercially available (Hanson, 2000;Barnard et al, 2009;Spaulding et al, 2011;Bodini et al, 2015;…”

Machine-Learning-Assisted Blood Parameter Sensing Platform for Rapid Next Generation Biomedical and Healthcare Applications

“…The flow cell serves as a controlled environment where the sample interacts with reagents and undergoes various chemical reactions. 29,30 The single flow cell is used for all analyses. It is assumed that the entire sample drains out of the flow cell using a peristaltic pump.…”