Simultaneous Determination of Creatinine, Creatine, and Guanidinoacetic Acid in Human Serum and Urine Using Liquid Chromatography–Atmospheric Pressure Chemical Ionization Mass Spectrometry

Abstract

A rapid and direct method for simultaneous determination of creatinine, creatine, and guanidinoacetic acid in biological samples has been developed by using column liquid chromatography–mass spectrometry (LC/APCI–MS). The determinations of creatinine, creatine, and guanidinoacetic acid in the samples of human urine and serum were carried out by scanning the [M + H]+ions of each compound. The recoveries of authentic compounds were 93.87 ± 6.00% (n= 5) for creatinine, 94.80 ± 8.93% (n= 5) for creatine, and 90.92 ± 7.96% (n= 5) for guanidinoacetic acid after ion-exchange resin treatment. The content of creatinine in human urine and serum was also measured by the Jaffé method, a common method of determination of creatinine currently used in hospitals. The contents of creatinine, creatine, and guanidinoacetic acid obtained using LC/APCI–MS coincided well with those reported in previous papers.