An evaluation of the Nova 2 ionised calcium instrument

An evaluation of the Nova 2 ionised calcium instrument

Many enzyme assays are linked to the formation or utilisation of NADH so that reaction rates can be monitored at 340 nm. The absorbance spectrum of naphthol green is sufficiently different from that of NADH to render calibration using this substance undesirable, and NADH or the particular chromophore used to monitor the reaction, e.g. p-nitrophenol, should be used. The new calibration procedure...

Further electrode evaluation of the Nova 2 ionised calcium instrument

Introduction In the original evaluation of the Nova 2 analyser [1] inter-electrode differences were shown which would have necessitated the re-establishment of the ionised calcium reference range each time that the calcium ion-selective electrode was changed. The manufacturers (Nova Biomedical, Newtown, Mass, USA) have now replaced the electrodes which showed slow and variable response times to...

Measurement of ionized calcium using the Nova 2 analyser

Measurement of ionised calcium concentration in neonates.

Whole blood ionised calcium concentration was measured simultaneously in capillary and arterial blood from neonates being nursed on an intensive care unit using an ion selective electrode. The mean arterio-capillary difference was -0.027 mmol/l (95% confidence intervals -0.041 to -0.012 mmol/l) and the limits of agreement between the two measurements were 0.034 and -0.088 mmol/l. Measurement of...

Serum ionised calcium concentration: measurement versus calculation.

Four hundred and eighteen measurements of serum ionised calcium, total calcium, and protein concentrations were made from 47 normal volunteers, 104 patients with chronic renal failure (33 being treated conservatively and 71 with regular haemodialysis), and 83 renal transplant recipients. The serum ionised calcium concentration was measured with an Orion SS-20 meter and calculated from the total...