[A new method for the determination of carboxyhemoglobin in fluid and dried blood using Fourier transformation infrared spectrometry].

A new technique is presented for the fast quantitative determination of carboxy-hemoglobin (CoHb) in liquid blood with the aid of Fourier transformation infrared spectrometry. The bands at v = 1953 and 1969 (cm-1), which are characteristic for the CoHb complex, were measured without the blood being prepared. In liquid samples the band at 1953 cm-1 is prominent; in dry samples, however, it appears. In moist samples both bands--each to be coordinated with a different CoHb conformer--are observed at about the same intensity. Even with dried blood spots of less than 0.1 mg, quantitative determination of CoHb at v = 1969 (cm-1) is possible. Systematic investigations of the thermic stability of the CoHb complex were performed. The typical interference phenomena associated with UV spectrometry were not observed when the above-described method was employed nor are they to be expected. Even under extreme measuring conditions, as for example when measuring transmission through lab-coat material, different CoHb contents could be determined in traces of dried blood.