Spectrophotometric determination of pH and carbonate ion concentrations in seawater: Choices, constraints and consequences

Ma, Jian; Shu, Huilin; Yang, Bo; Byrne, Robert H.; Yuan, Dongxing

doi:10.1016/j.aca.2019.06.024

Cited by 29 publications

(18 citation statements)

References 124 publications

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“…infrared spectrophotometry and coulometric titration [11][12][13][14][15][16][17]. These analytical methods require sample pre-treatment, which is a complex, time-consuming and insensitive process, cannot meet the demands of long-term field monitoring.…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, accurate knowledge of carbonate levels in seawater is necessary to maintain the balance of marine ecosystems, while the implementation of realtime monitoring of carbonate ion concentrations in hydrothermal fluids is a major advance in the detection of hydrothermal fields [2,3,[8][9][10]. Most of the commonly used methods for determining carbonate concentrations rely on laboratory analytical instruments such as gravimetric methods, colour change, equilibrium pressure, gas chromatography, infrared spectrophotometry and coulometric titration [11][12][13][14][15][16][17]. These analytical methods require sample pre-treatment, which is a complex, time-consuming and insensitive process, cannot 2 of 13 meet the demands of long-term field monitoring.…”

Section: Introductionmentioning

confidence: 99%

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Fabrication of an All-Solid-State Carbonate Ion-Selective Electrode with Carbon Film as Transducer and Its Preliminary Application in Deep-Sea Hydrothermal Field Exploration

Zhang

et al. 2021

Chemosensors

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Real-time measurements of carbonate ion concentrations in the ocean are critical to advancing marine environmental monitoring and research into deep-sea hydrothermal activity. Herein, we report the first example of deep-sea hydrothermal field exploration using a carbonate ion-selective electrode (ISE). The novel carbonate ISE was composed of a Ni wire as substrate, carbon film as transducers and carbonate-selective membrane layers. This paper describes the preparation process of the electrode and characterises its performance via scanning electron microscopy (SEM) and electrochemical analysis. The detection limit of the electrode for CO32− is 2.821 × 10−6 mol/L, the linear response range is 1.0 × 10−5–1.0 × 10−1 mol/L and the Nernst slope was −30.4 mV/decade. In April 2021, the carbonate ISE was mounted on multi-parameter sensors with pH and Eh (redox) electrodes for the search of hydrothermal activity at the Southwest Indian Ridge. The simultaneous potential anomalies appeared at this carbonate electrode with the pH and Eh electrodes when passing through the hydrothermal field. The study of the hydrothermal field was supported by the in situ camera video and the sulphide samples. Additionally, the carbonate electrode provides enhanced information of water chemistry for the study of the hydrothermal field.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fabrication of an All-Solid-State Carbonate Ion-Selective Electrode with Carbon Film as Transducer and Its Preliminary Application in Deep-Sea Hydrothermal Field Exploration

Zhang

et al. 2021

Chemosensors

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“…Thus, sample throughputs are up to 60 samples per hour [1,[11][12][13]. Almost all kinds of detection can be coupled to the above flow-based techniques, including UV-Vis absorbance [14][15][16][17][18][19][20][21][22], fluorescence [22][23][24], chemiluminescence [25,26], electrochemical detections (amperometry) [27][28][29][30], conductivity [31] and contactless conductivity [32][33][34][35][36][37].…”

Section: Introductionmentioning

confidence: 99%

Dual-Purpose Photometric-Conductivity Detector for Simultaneous and Sequential Measurements in Flow Analysis

et al. 2020

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This work presents a new dual-purpose detector for photometric and conductivity measurements in flow-based analysis. The photometric detector is a paired emitter–detector diode (PEDD) device, whilst the conductivity detection employs a capacitively coupled contactless conductivity detector (C4D). The flow-through detection cell is a rectangular acrylic block (ca. 2 × 2 × 1.5 cm) with cylindrical channels in Z-configuration. For the PEDD detector, the LED light source and detector are installed inside the acrylic block. The two electrodes of the C4D are silver conducting ink painted on the PEEK inlet and outlet tubing of the Z-flow cell. The dual-purpose detector is coupled with a sequential injection analysis (SIA) system for simultaneous detection of the absorbance of the orange dye and conductivity of the dissolved oral rehydration salt powder. The detector was also used for sequential measurements of creatinine and the conductivity of human urine samples. The creatinine analysis is based on colorimetric detection of the Jaffé reaction using the PEDD detector, and the conductivity of the urine, as measured by the C4D detector, is expressed in millisiemens (mS cm−1).

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“…It also can be used to detect physical characteristics such as temperature and conductivity. Spectrophotometer [9][10][11][12] is used for reagent detection of a physical parameter which is light. Another method is called the chromaticity.…”

Section: Introductionmentioning

confidence: 99%

Capacitance-based microfluidic device for early ammonia detection in river water

Ramli

Ahmad

2020

IJEECS

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<p>This paper proposes a design of a microfluidic device for early detection of ammonia in river water based on capacitance measurement. A microfluidic device is designed and simulated to measure the content of ammonia in river water by using the COMSOL finite element analysis (FEA) software. This paper describes the system in detail from the conceptual idea to the hardware implementation. The microfluidic device works by inserting the sample of water into the device to be tested. A pair of electrodes is connected to the electrical circuit and the value of the capacitance of the water sample is measured. The tested samples are normal river water and contaminated river water which have ammonia in it. Several investigations have been done via the simulation, i.e. the size of the electrode, the difference in water flow gap, the distance between the electrode, speed of the water and the capacitance of the water. The results show that the proposed microfluidic design is capable to detect ammonia inside river water under 2 ppm concentration.</p>

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Spectrophotometric determination of pH and carbonate ion concentrations in seawater: Choices, constraints and consequences

Cited by 29 publications

References 124 publications

Fabrication of an All-Solid-State Carbonate Ion-Selective Electrode with Carbon Film as Transducer and Its Preliminary Application in Deep-Sea Hydrothermal Field Exploration

Fabrication of an All-Solid-State Carbonate Ion-Selective Electrode with Carbon Film as Transducer and Its Preliminary Application in Deep-Sea Hydrothermal Field Exploration

Dual-Purpose Photometric-Conductivity Detector for Simultaneous and Sequential Measurements in Flow Analysis

Capacitance-based microfluidic device for early ammonia detection in river water

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