Direct Potentiometric Determination of Potassium and Sodium in Blood, Plasma, and Serum

Abstract

A potentiometric analyzer, developed to directly measure potassium and sodium concentrations, was evaluated on aqueous solutions, whole blood, serum, and plasma. The analyzer consists of three electrodes—sodium, potassium, and reference—mounted in a flow-cell configuration, and a modified digital pH meter, which displays the ion concentrations directly. Volume of the cell is about 100 µl. The electrodes equilibrate to each new sample in less than a minute. Calibrated with aqueous standard solution, the system yields essentially the same values for whole blood and the corresponding plasma, and results agree with those obtained for the same samples of plasma by flame photometry.

New trends in the treatment of hypokalemia in cows

“…Thus, by measuring this voltage, one would be able to ascertain the potassium concentration in a sample solution. Potassium is relatively low in concentration, thus amplification of the signal will be necessary to successfully detect it at clinically relevant concentration [23].…”

“…Principle References 1 Potentiometric direct measurement Valinomycin, selectively binds potassium and it, is pumped into a membrane inside the ion specific electrode. When valinomycin comes in contact with a potassium-containing solution, potassium binds to it, creating a potential difference relative to a reference and building up a charge [23] 2 Turbid-metric Potassium is precipitated using sodium tetraphenylborate. The turbidity is measured with spectrophotometer [24] 3 Smartphone-enabled quantification of potassium in the blood plasma Turbid metric principle [25] 4 Equipment-free detection of K+ Microfluidic paper-based analytical devices [26] Table 2.…”

Serum/plasma potassium monitoring using potentiometric point-of-care microanalyzers with improved ion selective electrodes

“…There are several clinical equipment to determine potassium ion mainly in serum or plasma samples such as ion chromatography (IC), flame photometry, inductively coupled plasma optical emission spectrometry or mass spectrometry (ICP-OES or ICP-MS), or potentiometry using ion selective electrodes (ISE) [4][5][6][7][8][9][10]. However, despite these analytical techniques fulfill some of the conditions to take adequate diagnosis in a clinical laboratory environment, they show some constraints such as long turnaround time (TAT), lack of portability, high cost, need of skilled professionals, limited working range or strict sample pretreatment requirements.…”

Crown-Ether Derived Graphene Hybrid Composite for Membrane-Free Potentiometric Sensing of Alkali Metal Ions

“…Moreover, the target ion is, in most cases, the ion present in the lowest concentration. For example, the potassium to sodium ratio in blood is approximately 1:30 . Potentiometric sensors record changes in analytic activity, but do not inherently have the selectivity needed, which is most commonly achieved by using an ion-selective membrane that can limit the interference ions flux to the electrode. − …”

“…For example, the potassium to sodium ratio in blood is approximately 1:30. 12 Potentiometric sensors record changes in analytic activity, but do not inherently have the selectivity needed, which is most commonly achieved by using an ionselective membrane that can limit the interference ions flux to the electrode. 13−15 In this study, we have synthesized a new electrode material based on 18-crown [6]ether functionalized RGO.…”