Determination of the ionised and ultrafilterable calcium of normal human plasma

Ga, Rose

doi:10.1016/0009-8981(57)90107-9

Cited by 106 publications

(15 citation statements)

References 20 publications

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“…This study suggests a similar problem: when protein was separated by ultrafiltration, the apparent ionized calcium fell more than the approximately 5 anticipated from the Donnan effect [10]. Also, the correlation observed between ionized calcium and protein levels in patient samples tends to confirm this hypothesis.…”

Section: Discussionsupporting

confidence: 65%

Measurement of ionized calciumusing the Nova 2 analyser

Ferreira

Jacobson

1983

Journal of Analytical Methods in Chemistry

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Section: Discussionsupporting

confidence: 65%

Measurement of ionized calciumusing the Nova 2 analyser

Ferreira

Jacobson

1983

Journal of Analytical Methods in Chemistry

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“…As reported by Rose (1957) and Pederson (1969) increase in protein concentration had no effect on results. Pederson (1969) also showed that dilution of serum by 50~'-;; with its own ultrafiltrate had no effect on results and that ultrafilterable calcium concentrations were completely independent of the volume of serum used or the ultrafiltration pressure applied.…”

Section: Discussionsupporting

confidence: 62%

Measurement of Total, Ultrafilterable and Ionised Serum Calcium

Rushton¹,

Sammons²,

Gosling³

et al. 1973

Ann Clin Biochem

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The development and assessment of methods for measurement of total, ultrafilterable and ionised serum calcium is given. An existing fluorimetric technique for total calcium has been automated and modified for routine use. A device for rapidly preparing serum ultrafiltrates has been developed and an electrometric method for ionised calcium measurement assessed. Values in normal subjects are given for all three fractions and compared with the findings of other workers.

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“…Ionized calcium measurement in a solution may be performed by several methods based on different analytical principles: the biological "frog heart" method (1), spectrophotometry with calcium indicators (2)(3)(4)(5), and potentiometry with calcium ion-selective electrodes (ISE) (6)(7)(8)(9)(10)(11)(12)(13)(14) which respond to changes in thermodynamic activity of calcium ions. For ionized calcium measurement in plasma, potentiometry is the method of choice for the reference method.…”

Section: Methods Of Measurementmentioning

confidence: 99%

IFCC Recommended Reference Method for the Determination of the Substance Concentration of Ionized Calcium in Undiluted Serum, Plasma or Whole Blood

Burnett¹,

Christiansen²,

Covington³

et al. 2000

Clinical Chemistry and Laboratory Medicine

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A reference method is described for the determination of the substance concentration of ionized calcium in plasma by which ionized calcium (free or unbound) may be reliably determined on the basis of calibration with aqueous solutions with known concentration of ionized calcium. The composition of the calibration solutions is chosen such that the activity coefficient of the calcium ion is assumed to be identical both in the calibration solutions and in "normal" plasma, i.e. by convention, the ionic strength (Im) is 0.160 mol/kg. The convention is adopted of reporting ionized calcium measurements as concentration expressed as mmol/l. The proposed reference method for ionized calcium measurement in plasma is based on the use of a cell consisting of an external reference electrode with a saturated potassium chloride liquid/liquid junction in combination with a calcium ion-selective membrane electrode of defined construction and performance. Procedures for using the reference cell and a protocol for sample measurement are described. The preparation of the calibration solutions to be used are described in detail in Appendix A, secondary calibration solutions and check standards in Appendix B, and reference cell vessel design in Appendix C.

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Determination of the ionised and ultrafilterable calcium of normal human plasma

Cited by 106 publications

References 20 publications

Measurement of ionized calciumusing the Nova 2 analyser

Measurement of ionized calciumusing the Nova 2 analyser

Measurement of Total, Ultrafilterable and Ionised Serum Calcium

IFCC Recommended Reference Method for the Determination of the Substance Concentration of Ionized Calcium in Undiluted Serum, Plasma or Whole Blood

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