Problems with the external quality assessment of accuracy of point of care devices (POCD) for blood glucose are independent of sample composition.

This short article describes the results obtained in both internal and external quality assessment of point of care devices (POCD) for the monitoring of blood glucose. The results show that the use of synthetic, serum and whole blood matrices for the samples do not markedly change the inaccuracy of measurement. It is only possible to check precision of POC devices for glucose in external quality assessment (EQA) surveys for POC devices for blood glucose.

Comparability of method results and performance in a national external quality assessment scheme between 1993 and 2003 using thyroid associated analytes as examples.

Six thyroid analytes (free and total triiodothyronine and thyroxine, thyrotropin and thyroglobulin) have been followed up over a 10 year period in a national external quality assessment scheme (EQAS) organised by the Institute for Standardisation and Documentation in the Medical Laboratory (INSTAND). I. The following points were observed: II.

Comparability of method results and performance in a national external quality assessment scheme between 1993 and 2003 using thyroid associated antibodies as examples.

Four thyroid antibodies (antibodies to microsomes [MAb], thyroid peroxidase [anti-TPO], thyroglobulin [anti-Tg] and TSH-receptor [TRAB, THYBIA]) have been followed up over a 10-year period in a national external quality assessment scheme (EQAS) organised by the Institute for Standardisation and Documentation in the Medical Laboratory (INSTAND e.V.).

Determination of the cardiac glycosides digoxin and digitoxin by liquid chromatography combined with isotope-dilution mass spectrometry (LC-IDMS)--a candidate reference measurement procedure.

This article describes a method of high analytical sensitivity, reproducibility and trueness for the determination of digoxin and digitoxin in serum or plasma at therapeutic levels using a combination of high-pressure liquid chromatography (HPLC), isotope-dilution mass spectrometry (IDMS) and caesium-adduct formation. A method for threefold deuterium substitution in the glycosides was developed, which could be performed within 24 hours without distillation giving yields > 98% of the theoretical value. Extraction from a serum or plasma matrix was performed using a liquid-phase extraction with ammonium acetate buffer/tertiary butylmethyl ether/ethyl acetate at pH 9.

The determination of free and protein-bound haemoglobin in plasma using a combination of HPLC and absorption spectrometry.

The aim of the study was to develop a method for the determination of haemoglobin in plasma suitable for use to set target values for external quality assessment schemes for this analyte using commercially available test kits and equipment. In the early phase of the method development it became clear that the use of a single method, namely HPLC, would not be possible. However, by combining HPLC and absorption spectrophotometry, both qualitative and quantitative rapid determinations of protein-bound and free haemoglobin were able to be performed on equipment present in most routine clinical chemistry laboratories.