Rapid determination of creatinine in serum and urine by ion-pair high-performance liquid chromatography.
We report a simple and reliable high performance liquid chromatography method for measuring creatinine in serum and urine. The chromatographic run is performed on a C(18) column after protein precipitation with acetone and addition of cimetidine as an internal standard. The separation is carried out in 20 min at a flow rate of 0.8 ml/min, with a mobile phase consisting of 100 mmol/l sodium dihydrogen phosphate solution, containing 30 mmol/l sodium lauryl sulfate pH 3.0 and acetonitrile (60:36, v/v). The absorbance is monitored at 200 nm. The relationship between creatinine concentration and the creatinine/internal standard peak area is linear up to 1,088 micromol/l. Within-run precision measured at three different creatinine concentrations ranges from 0.89% to 2.34% in serum and from 0.34% to 1.10% in urine. Between-run precision varies from 1.68% to 3.17% in serum and from 1.58% to 1.85% in urine over a wide range of concentrations. Analytical recovery is between 98.71% and 101.25% in serum and between 98.96% and 100.27% in urine. The detection limit is 3.24 micromol/l for a signal-to-noise ratio of 3. The method shows a good linearity with the reference isotope dilution gas chromatography-mass spectrometry procedure (r=0.999), without interferences, even in the presence of high bilirubin concentrations.
Marsilio
R
R
Department of Pediatrics, University Hospital of Padua, Via Giustiniani 3, I-35128, Padua, Italy.
Dall'Amico
R
R
Giordano
G
G
Murer
L
L
Montini
G
G
Ros
M
M
Bacelle
L
L
Plebani
M
M
Dussini
N
N
Zacchello
G
G
D001663:Bilirubin / Q000097:blood / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D003404:Creatinine / Q000097:blood* / Q000592:standards / Q000652:urine*; D005069:Evaluation Studies as Topic; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000652:urine; D012015:Reference Standards; D015203:Reproducibility of Results
D003404:Creatinine; D001663:Bilirubin