Comparative evaluation of different spectrophometric methods for the determination of small amounts of carboxyhaemoglobin.

Four spectrophotometric methods measuring HbCO were investigated in comparison with an analyzer (CO-Oximeter) in order to find a method determining HbCO fractions) below 0.10 with sufficient reliability. The CO-Oximeter was chosen as "reference" method because results of other authors with this instrument yielded good agreement with other methods, e.g. IR-spectrometry, GLC, van Slyke. Only the five wavelength method of Commins & Lawther (1965) Brit. J. Industr. Med. 22, 139--143) can be recommended, for it yielded CV's and sensitivities comparable to the CO-Oximeter. The within-run precision had CVs of 2.3% to 4.7%, the sensitivity was 0.0021 to 0.0028. The method is suited even for HbCO measurements of shorter series.