Detection and quantitation of gadolinium chelates in human serum and urine by high-performance liquid chromatography and post-column derivatization of gadolinium with Arsenazo III.
A narrow-bore high-performance liquid chromatography method was developed for simultaneous separation of gadolinium diethylenetriaminepentaacetic acid (GdDTPA), the monomethylamide (GdDTPA-MMA) and the bis-methylamide (GdDTPA-BMA) in human serum and urine. The Gd complexes were detected at 658 nm after post-column derivatization with Arsenazo III. The serum samples were ultrafiltrated, whereas the urine samples were centrifuged and diluted before analysis. With an injection volume of 10 microliters on a 2.1 mm ID reversed-phase column, the limit of detection of GdDTPA-BMA was calculated as 0.3 microM and 1.1 microM in serum and urine, respectively. The method was validated with respect to GdDTPA-BMA with a limit of quantification set to 2 microM and 10 microM in serum and urine, respectively. The best fit of the calibration curve was obtained using non-linear regression according to the equation Y = A+BX+CX2 in the concentration ranges 2-800 microM and 10-2000 microM of GdDTPA-BMA in serum and urine, respectively. The precision of the method was found to range from 1 to 4% RSD. The recoveries of GdDTPA-BMA spiked in serum and urine were higher than 95% with an RSD equal to or less than 4%. The serum samples were stable for at least 5 months when stored at -70 degrees C, and the urine samples were stable for a least 6 months when stored at -20 degrees C.
Hvattum
E
E
Nycomed Imaging AS, Torshov, Oslo, Norway.
Normann
P T
PT
Jamieson
G C
GC
Lai
J J
JJ
Skotland
T
T
D000577:Amides / Q000032:analysis / Q000097:blood / Q000652:urine; D001150:Arsenazo III / Q000737:chemistry*; D002614:Chelating Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D005682:Gadolinium / Q000032:analysis* / Q000097:blood / Q000652:urine; D019786:Gadolinium DTPA; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry*; D008297:Male; D009942:Organometallic Compounds / Q000032:analysis* / Q000097:blood / Q000652:urine; D004369:Pentetic Acid / Q000031:analogs & derivatives / Q000032:analysis; D012680:Sensitivity and Specificity
D000577:Amides; D002614:Chelating Agents; D007202:Indicators and Reagents; D009942:Organometallic Compounds; D001150:Arsenazo III; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA