Preparation of carboxyhemoglobin standards and calculation of spectrophotometric quantitation constants.
A method was developed for the preparation of carboxyhemoglobin (COHB) standards, which were stable for more than four months with the prepared control remaining within acceptable limits during this time. A mathematical equation was developed to more accurately determine the constants A and B used in the equation COHB% = 100[(C - B)/(A - B)], where B = 0% COHB peak ratio at 540 nm and 579 nm; A = 100% COHB peak ratio at 540 nm and 579 nm; and C = the peak ratio at 540 nm and 579 nm for the blood being analyzed. The following equations were developed to calculate A and B: B = Pavg - (P) [(Pavg - Navg)/(P - N)]; A = B + (Pavg - Navg)/(P - N), Pavg = average peak ratio 540/579 for the positive standard run on the spectrophotometer; P = average decimal concentration measured on the CO-OXIMETER for the positive standard; Navg = average peak ratio 540/579 for the negative standard; N = average decimal concentration measured on the CO-OXIMETER for the negative standard. The new equations provided results consistent with those obtained from a CO-OXIMETER.
Canfield
D V
DV
Civil Aeromedical Institute, Federal Aviation Administration, Toxicology and Accident Research Laboratory, Oklahoma City, OK 73125-5066, USA.
Smith
M
M
Ritter
R M
RM
Chaturvedi
A K
AK
D002263:Carboxyhemoglobin / Q000032:analysis*; D006801:Humans; D010092:Oximetry / Q000379:methods / Q000592:standards*; D011786:Quality Control; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet
D002263:Carboxyhemoglobin