Assessment of the Methods Available for the Determination of Carbon Monoxide in Blood

Abstract

Experimental evaluation of methods for assessing the carboxyhemoglobin (COHb) content in blood using gas chromatography, UV-visible spectrophotometry (three methods), and magnetic circular dichroism (MCD) has been made. From the point of view of measurements where the COHb content is low (less than 15%), elevated simply by the smoking population, the spectrophotometric method by Rodkey, et al. (7) emerges as the most satisfactory. MCD analysis, however, is potentially considerably simpler, not requiring chemical pretreatment of the blood, and provided that analysis time can be improved, is likely to replace the spectrophotometric method as the method of choice.

Carboxyhemoglobin in the rat: Improvements in the spectrophotometric measurement and comparison to other studies

“…Wigfield et al . 4 in an assessment of spectrophotometric methods for CO in blood, found that the C and L method gave 'high values at low COHb, and low values at high COHb, values being approximately correct at 60% COHb'. In order to improve the accuracy of the C and L method, particularly at high COHh saturation.…”

Accuracy profile validation of a new method for carbon monoxide measurement in the human blood using headspace-gas chromatography–mass spectrometry (HS-GC–MS)

“…Numerous methods have been described to study the effect of the added reagent to whole blood on the liberation of CO. Potassium ferricyanide was the most commonly used substance as the liberating agent [4,5,[10][11][12][13][14][15] and resulted in better CO release than potassium ferrocyanide, especially when mixing was applied [16,17]. Acids, such as sulfuric acid [9,13,[18][19][20][21], lactic acid [13], citric acid [13,16], and phosphoric acid [16] have also been studied, and have provided good results.…”

“…This detector has been improved upon to produce the micro TCD, which is a more convenient [18,19,33] method. An alternative to the TCD is Flame Ionization Detector (FID) that is coupled to a nickel catalyst placed before the FID [3,10,11,15]. The use of the FID provides the specificity and sensitivity required at low CO levels through the conversion of CO to methane by a nickel-hydrogen reduction [17,34].…”

Determinação espectrofotométrica da caboxiemoglobinemia em indivíduos expostos ocupacionalmente ao monóxido de carbono

“…A porcentagem de COHb é calculada correlacionando-se as absorvâncias da amostra com os coeficientes de absortividade molar da Hbred e da COHb nos comprimentos de onda apropriados. O método é trabalhoso em termos de cálculos matemáticos, mas os resultados são exatos e reprodutíveis l58 • WIGFIED et aL 207 Esse tipo de análise segue a lei de Lambert-Beer. Se os componentes da mistura não interagirem, a solução que contenha n componentes, com espectros de absorção suficientemente diferentes, pode ser analisada pela medida da absorvância em pelo menos n comprimentos de onda.…”

“…A figura 9 mostra os espectros de absorção das soluções de oxiemoglobina e carboxiemoglobina e o espectro diferencial.Tabela IV -Principais métodos para determinação da carboxiemoglobinemia COHb esperados e os encontrados. WIGFIELD et aI 207,. estudando este método, relataram não obter a mesma linearidade reportada pelos autores, detectando valores elevados para baixas % de COHb, valores baixos para as altas concentrações e valores equivalentes para teores médios de COHb.Este método foi mais tarde simplificado por BUCHWALD29 (1969).…”