What are the limitations of methods to measure carbon monoxide in biological samples

Purpose Carbon monoxide (CO) is one of the most important toxic gases in the atmosphere. Its high affinity for hemoglobin has made carboxyhemoglobin (COHb) the most appropriate biomarker for CO poisoning. COHb is measured using spectrophotometric (ultraviolet-spectrophotometry, CO-oximetry) or gas chromatographic (GC) methods combined with flame ionization or mass spectrometry (MS) detectors. However, inconsistencies in many cases have been reported between measured values and reported symptoms, raising doubts as to the suitability of COHb as a biomarker and the accuracy and reliability of its measurement methods. Therefore, we aimed to review the accuracy of current methods used to measure CO and to determine their sources of error and their effects on the interpretation process.