Determination of potassium by dry reagent carrier technology: a multicentre evaluation.

We describe the construction, the reaction principle and the performance of Reflotron K+, a new Reflotron test for the quantitative determination of potassium in serum and heparinized plasma. The reaction principle is based on the introduction of the potassium cation via valinomycin into a non-polar phase; the accompanying loss of protons from the non-polar phase is detected by the colour change of a pH indicator. The multicentre evaluation of the reagent carrier system showed in median CVs of < 0.

[Results of multicenter evaluation of reagents for determination of sodium, potassium and chloride ions using enzyme activation].

We present the results of a multicentre evaluation with Boehringer Mannheim/Hitachi instruments of new "enzymatic" methods for the determination of Na+, K+, and Cl- in serum or plasma. The between-day coefficient of variation was less than 1.4% (Na+), less than 2.

A candidate reference method for the determination of magnesium in serum.

A candidate reference method for the determination of magnesium in serum (analytical range 0.5 to 2.0 mmol/l) by flame atomic absorption spectrometry was commissioned.

Serum beta 2-microglobulin level in type I diabetes: its dependence on the duration of diabetes and the quality of metabolic control.

As the level of serum beta 2-microglobulin (beta 2-M) has been shown to reflect renal function, its concentration was determined in serum and urine of patients affected by diabetes type I of various duration and quality of metabolic control. 104 diabetic patients, aged 7-39 (mean, 14.8) years, with an average duration of diabetes of 5.

[Myoglobin-latex test. A new rapid test for the improvement of the early diagnosis of acute myocardial infarct].

Myoglobin concentrations were determined radioimmunologically and with a semiquantitative rapid latex test in 684 serum samples. There was a good correlation of both tests. The latex test becomes positive above 90 micrograms/l, i.