Creatinine measurements in 24 h urine by liquid chromatography--tandem Mass Spectrometry.
A simple, sensitive, and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining urinary creatinine was developed and used to evaluate 24 h urine samples collected during an exposure study. Urine (1 microL) was diluted with methanol and then directly applied to LC-MS/MS. Under electrospray ionization (ESI) conditions, the transition molecules of creatinine and creatinine- d3 were observed at m/ z 114 > 44 and m/ z 117 > 47, respectively. The retention time of creatinine was 0.59 min. The linear range was 1-2000 ng/mL, with a detection limit in urine of 1 ng/mL. LC-MS/MS and colorimetric end-point methods were significantly associated ( R2 = 0.8785, p < 0.0001). The LC-MS/MS method to determine creatinine in 24 h urine samples had shorter retention times, was more sensitive, reliable, reproducible, simple, selective, and used a smaller sample size than other LC-MS/MS or commercial methods.
Park
Eun-Kee
EK
Department of Entomology and Cancer Research Center, and Department of Public Health Sciences, University of California, Davis, CA 95616, USA.
Watanabe
Takaho
T
Gee
Shirley J
SJ
Schenker
Marc B
MB
Hammock
Bruce D
BD
D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000652:urine*; D019605:Euryarchaeota; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry; D013997:Time Factors
D003404:Creatinine