Validation of Liquid Chromatography–Tandem Mass Spectrometry Method for Analysis of Urinary Conjugated Metanephrine and Normetanephrine for Screening of Pheochromocytoma

摘要: Background: Metanephrines are biochemical markers for tumors of the adrenal medulla (e.g., pheochromocytoma) and other derived from neural crest cells paragangliomas neuroblastomas). We describe a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method measurement urinary conjugated metanephrines. Methods: added 250 ng d3-metanephrine (d3-MN) 500 d3-normetanephrine (d3-NMN) to 1 mL urine samples as stable isotope internal standards. The were then acidified, hydrolyzed 20 min in 100 °C water bath, neutralized, prepared by solid-phase extraction. methanol eluates analyzed LC-MS/MS selected-reaction-monitoring mode after separation on reversed-phase amide C16 column. Results: Multiple calibration curves analysis MN NMN exhibited consistent linearity reproducibility range 10–5000 μg/L. Interassay CVs 5.7–8.6% at mean concentrations 90–4854 μg/L NMN. detection limit was 10 Recovery (144–2300 μg/L) 91–114%. regression equation ( x ) colorimetric y methods was: = 0.81 − 0.006 r 0.822; n 110). HPLC 1.09 + 0.05 0.998; 40). Conclusions: sensitivity specificity MS/MS metanephrines offer advantages over colorimetric, immunoassay, HPLC, gas chromatography–mass because elimination drug interferences, high throughput, short chromatographic run time.