Performance of DGT (diffusive gradients in thin films) for measuring Ca and Mg in freshwater.

Lancaster Environment Centre

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https://doi.org/10.1016/S0003-2670(02)00248-9
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Keywords

Calcium, Magnesium, Diffusion, Diffusive gradients in thin films, Ion exchange, pH

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Performance of DGT (diffusive gradients in thin films) for measuring Ca and Mg in freshwater. / Dahlqvist, Ralf; Zhang, Hao; Ingri, Johan et al.
In: Analytica Chimica Acta, Vol. 460, No. 2, 05.06.2002, p. 247-256.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Author

Dahlqvist, Ralf ; Zhang, Hao ; Ingri, Johan et al. / Performance of DGT (diffusive gradients in thin films) for measuring Ca and Mg in freshwater. In: Analytica Chimica Acta. 2002 ; Vol. 460, No. 2. pp. 247-256.

Bibtex

@article{c02882c7405a47c8aff583abe7249be2,

title = "Performance of DGT (diffusive gradients in thin films) for measuring Ca and Mg in freshwater.",

abstract = "Measurements of the major cations Ca and Mg by the technique of diffusive gradients in thin films (DGTs) were systematically evaluated. The concentration in solution was calculated using Fick{\textquoteright}s first law of diffusion from the directly measured flux to the DGT device. A selective cation exchange resin (Bio-Rad Chelex{\textregistered}100), which has been used extensively with DGT for trace metals, such as Cd2+, Cu2+ and Ni2+, was used for this work. Elution of Ca and Mg from the resin with 1 M HNO3 was very reproducible. Measurements of Ca and Mg concentrations in synthetic solutions agreed well with the theoretical predictions. The negative response on uptake caused by lowered pH was investigated. Uptake was found to decline below pH 5. The capacity of the DGT device for Ca and Mg was also investigated to establish maximum deployment times for given concentrations. Experiments with filtered and modified lake water show that DGT can be used to measure Ca and Mg when trace metals are present in the solution. An in situ deployment of DGT combined with an ultrafiltration study suggest that the Mg concentration measured by DGT is similar to the concentration found in the fraction <1 kDa.",

keywords = "Calcium, Magnesium, Diffusion, Diffusive gradients in thin films, Ion exchange, pH",

author = "Ralf Dahlqvist and Hao Zhang and Johan Ingri and William Davison",

year = "2002",

month = jun,

day = "5",

doi = "10.1016/S0003-2670(02)00248-9",

language = "English",

volume = "460",

pages = "247--256",

journal = "Analytica Chimica Acta",

issn = "0003-2670",

publisher = "Elsevier Science B.V.",

number = "2",

}

RIS

TY - JOUR

T1 - Performance of DGT (diffusive gradients in thin films) for measuring Ca and Mg in freshwater.

AU - Dahlqvist, Ralf

AU - Zhang, Hao

AU - Ingri, Johan

AU - Davison, William

PY - 2002/6/5

Y1 - 2002/6/5

N2 - Measurements of the major cations Ca and Mg by the technique of diffusive gradients in thin films (DGTs) were systematically evaluated. The concentration in solution was calculated using Fick’s first law of diffusion from the directly measured flux to the DGT device. A selective cation exchange resin (Bio-Rad Chelex®100), which has been used extensively with DGT for trace metals, such as Cd2+, Cu2+ and Ni2+, was used for this work. Elution of Ca and Mg from the resin with 1 M HNO3 was very reproducible. Measurements of Ca and Mg concentrations in synthetic solutions agreed well with the theoretical predictions. The negative response on uptake caused by lowered pH was investigated. Uptake was found to decline below pH 5. The capacity of the DGT device for Ca and Mg was also investigated to establish maximum deployment times for given concentrations. Experiments with filtered and modified lake water show that DGT can be used to measure Ca and Mg when trace metals are present in the solution. An in situ deployment of DGT combined with an ultrafiltration study suggest that the Mg concentration measured by DGT is similar to the concentration found in the fraction <1 kDa.

AB - Measurements of the major cations Ca and Mg by the technique of diffusive gradients in thin films (DGTs) were systematically evaluated. The concentration in solution was calculated using Fick’s first law of diffusion from the directly measured flux to the DGT device. A selective cation exchange resin (Bio-Rad Chelex®100), which has been used extensively with DGT for trace metals, such as Cd2+, Cu2+ and Ni2+, was used for this work. Elution of Ca and Mg from the resin with 1 M HNO3 was very reproducible. Measurements of Ca and Mg concentrations in synthetic solutions agreed well with the theoretical predictions. The negative response on uptake caused by lowered pH was investigated. Uptake was found to decline below pH 5. The capacity of the DGT device for Ca and Mg was also investigated to establish maximum deployment times for given concentrations. Experiments with filtered and modified lake water show that DGT can be used to measure Ca and Mg when trace metals are present in the solution. An in situ deployment of DGT combined with an ultrafiltration study suggest that the Mg concentration measured by DGT is similar to the concentration found in the fraction <1 kDa.

KW - Calcium

KW - Magnesium

KW - Diffusion

KW - Diffusive gradients in thin films

KW - Ion exchange

KW - pH

U2 - 10.1016/S0003-2670(02)00248-9

DO - 10.1016/S0003-2670(02)00248-9

M3 - Journal article

VL - 460

SP - 247

EP - 256

JO - Analytica Chimica Acta

JF - Analytica Chimica Acta

SN - 0003-2670

IS - 2

ER -

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