title: Quantification of Iohexol in Serum by High-Performance Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).
abstract: Iohexol is a nonradioactive contrast medium, and its clearance from serum or urine is used to measure glomerular filtration rate (GFR). GFR is the most useful indicator of kidney function and progression of kidney disease. GFR determination using iohexol clearance is increasingly being applied in clinical practice, given its advantages over and correlation with inulin. We describe a high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) method for iohexol clearance, requiring only 50 μL of serum. The sample preparation involves protein precipitation with LC/MS-grade methanol, containing ioversol as the internal standard. Samples are centrifuged and supernatant is dried under nitrogen gas at room temperature. Samples are reconstituted with mobile phase (ammonium acetate-formic acid-water). Iohexol is separated using an HPLC gradient method on a C-8 analytical column. MS/MS detection is in the multiple-reaction monitoring (MRM) mode and the transitions monitored are m/z 822.0 to m/z 804.0 and m/z 807.0 to m/z 588.0 for iohexol and ioversol, respectively.
authors.affiliation: Department of Pathology, Northwestern University Feinberg School of Medicine, 225 East Chicago Avenue, Box 17, Chicago, IL, 60611-2605, USA.
authors.forename: Faye B
authors.initials: FB
authors.lastname: Vicente
authors.affiliation: Department of Pathology, Northwestern University Feinberg School of Medicine, 225 East Chicago Avenue, Box 17, Chicago, IL, 60611-2605, USA.
authors.forename: Gina
authors.initials: G
authors.lastname: Vespa
authors.affiliation: Department of Pathology, Northwestern University Feinberg School of Medicine, 225 East Chicago Avenue, Box 17, Chicago, IL, 60611-2605, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Miller
authors.affiliation: Department of Pathology, Northwestern University Feinberg School of Medicine, 225 East Chicago Avenue, Box 17, Chicago, IL, 60611-2605, USA. shaymond@luriechildrens.org.
authors.forename: Shannon
authors.initials: S
authors.lastname: Haymond
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003287:Contrast Media / Q000493:pharmacokinetics*; D006801:Humans; D007472:Iohexol / Q000493:pharmacokinetics*; D018401:Sample Size; D044967:Serum / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol
keywords: Glomerular filtration rate; Iohexol; Liquid chromatography; Mass spectrometry; Quantification; Serum