title: Rapid, easy analysis of urinary vanillylmandelic acid for diagnostic testing of pheochromocytoma by liquid chromatography tandem mass spectrometry.
abstract: Vanillylmandelic acid (VMA), as one of the most important catecholamine metabolites, is commonly used to aid in diagnosis of pheochromocytoma. This study develops a rapid and simple high-throughput LC-MS/MS method for the measurement of urinary VMA. Without sample pretreatment, the urine specimens were mixed with internal standard (IS) solution for direct analysis by LC-MS/MS in two minutes. VMA and VMA-d3 were detected in the multiple-reaction monitoring mode using the specific transitions m/z 197.0→137.0 and 200.0→140.0, respectively. This method was validated for consistent linearity from 1.0 to 250.0μM with CVs≤3.12%, excellent recovery, good stability and low carryover. The lowest limit of quantification (LLOQ) was 0.125μmol/L for VMA with CV of 14.1%, and the lower limit of detection (LOD) was 0.025μmol/L. Intra-assay and inter-assay imprecision values (CVs) for VMA were all below 2.11%. Dilution linearity was investigated with a satisfied mean accordance of 105%. Method comparison of LC-MS/MS and microcolumn chromatography in our lab was performed and the reference interval was established in agreement with that of the Mayo Clinic. All these results demonstrate that this validated LC-MS/MS approach shows improved accuracy and reproducibility compared with microcolumn chromatography. The low sample volume, simplicity, rapidity, and robustness of the method make it suitable for use as a high-throughput assay in routine clinical biochemistry laboratories.
authors: Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.
authors: Ying
authors: Y
authors: Shen
authors: Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.
authors: Jie
authors: J
authors: Lu
authors: Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.
authors: Qing
authors: Q
authors: Tang
authors: Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.
authors: Qing
authors: Q
authors: Guan
authors: Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.
authors: Ziyong
authors: Z
authors: Sun
authors: Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.
authors: Huijun
authors: H
authors: Li
authors: Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China. Electronic address: chengliming2015@163.com.
authors: Liming
authors: L
authors: Cheng
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000175:diagnosis*; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D010673:Pheochromocytoma / Q000175:diagnosis*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014642:Vanilmandelic Acid / Q000652:urine*
chemical_list: D014642:Vanilmandelic Acid
keywords: LC–MS/MS; Pheochromocytoma; Vanillylmandelic acid