Abstract: Objective To confirm whether formaldehyde disturb detecting carbon monoxide in blood.To give an evidence that can be used for detecting carboxyhemoglobin more accurately in carbon monoxide poisoning ap-praises.Methods Blood samples came from carbon monoxide poisoning and the health were collected.Regular methods for detecting carboxyhemoglobin were used.Observing and comparing the detection results between which were spiked with methanal and no spiked one were performed.Results Methanal will affect the result of following experiments such as heating,adding NaOH,absorbed by PdCl 2 and spectrophotometry.Conclusion The samples which contaminated by formaldehyde couldn't be used for detecting carboxyhemoglobin.

Key words: carbon monoxide poisoning, formaldehyde, disturbing detecting