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Biomedical subjects

E J Van Kampen

Publications and source records attributed to E J Van Kampen.

8 recordsLinked to original sources
PubMed1977

Carboxyhaemoglobin. Spectrophotometric determination tested and calibrated using a new reference method for measuring carbon monoxide in blood.

The spectrophotometric determination of HbCO at lambda = 562 and 540 nm in the system HbCO/HbO2 was reinvestigated using a new reference method for measuring CO in blood. This reference method is based on the conversion of CO from HbCO into CO2 which is determined by titration. Plotting the absorbance ratio A562/A540 against the titrimetrically determined HbCO fractions of 46 blood samples demonstrated a linear relationship up to 90% HbCO and yielded more accurate values for the constants in the equation for calculating the HbCO fraction from A562/A540. The standard deviation of the differences between the spectrophotometric and the titrimetric method was 1.2% HbCO. It is shown that the influence of other haemoglobin derivatives and other possible sources of error is either negligible or can be prevented by simple precautions.

Carbon Monoxide↗
PubMed1977

Experience in the Netherlands with an external quality control and scoring system for clinical chemistry laboratories.

A procedure is described to judge the quality of clinical chemistry hospital laboratories in The Netherlands. In 1974, 45% of the laboratories took part in the national control scheme. A score system of the results, independent of the standard deviation, opens a provisional possibility to strive for (dynamic) reference laboratories. The Youden plots possibly will unveil systematic method-differences. Discrepancies in results seem to be caused as much by methods/instruments applied, as by unknown factors which are under investigation now.

Chemistry, Clinical↗
PubMed1976

Quality control in haemoglobinometry with special reference to the stability of haemiglobincyanide reference solutions.

In haemoglobinometry grave errors are still being made even though an internationally accepted standardized method is available for the determination of the haemoglobin content of blood. Up to the present only haemiglobincyanide reference solutions have been available on a wide scale to check the measuring stage of the standardized haemiglobincyanide method. These reference solutions are shown to remain stable, under proper storage conditions, for more than 10 years. Concentrated haemoglobin solutions have become available recently, offering the possibility to control the dilution and conversion steps of the haemiglobincyanide method. Such a solution is shown to remain stable, under proper storage conditions, for at least a year. Using both haemiglobincyanide reference solutions and concentrated haemoglobin solutions, as well as having the possibility of checking the cyanide content of the reagent used, an acceptable intra-laboratory control program may now be set up.

Cyanides↗