Simultaneous analysis of neuroendocrine tumor markers by HPLC-electrochemical detection.
A validated, high pressure liquid chromatographic (HPLC) method for simultaneous quantitation of urinary catecholic acids 4-hydroxy-3-methoxymandelic acid (HMMA) (vanylmandelic acid) (VMA), 4-hydroxy-3-methoxyphenylacetic acid (HVA) and 5-hydroxyindole-3-acetic acid (5-HIAA) was developed. Sample preparation involved liquid-liquid extraction of acidified urine, containing iso-HMMA (IS) as internal standard, with ether, evaporation of the organic extract, followed by reconstitution of the residue in phosphate buffer at pH 3.3. After reversed-phase HPLC at 35 degrees C and separation on a Licrospher 125mmx4mm C(18) column (5microm particle size) with phosphate buffer (pH 3.5)-acetone (950:50, v/v) as eluent, quantitation is achieved by electrochemical detection using coulometric detection at a potential of +350mV. The method was successfully applied to routine diagnosis of neuroblastoma, carcinoid syndrome and pheochromocytoma.
Manickum
T
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Department of Chemical Pathology (Chromatography Section), National Health Laboratory Services (NHLS), Inkosi Albert Luthuli Central (IALC) Hospital (IALCH), 800 Bellair Road, Mayville 4058, South Africa. thavrin.manickum@umgeni.co.za
D000310:Adrenal Gland Neoplasms / Q000175:diagnosis; D000328:Adult; D014408:Biomarkers, Tumor / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods; D005260:Female; D006719:Homovanillic Acid / Q000652:urine*; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine*; D008297:Male; D008303:Malignant Carcinoid Syndrome / Q000175:diagnosis; D008875:Middle Aged; D009447:Neuroblastoma / Q000175:diagnosis; D018358:Neuroendocrine Tumors / Q000175:diagnosis*; D010673:Pheochromocytoma / Q000175:diagnosis; D012680:Sensitivity and Specificity; D014642:Vanilmandelic Acid / Q000652:urine*
D014408:Biomarkers, Tumor; D006897:Hydroxyindoleacetic Acid; D014642:Vanilmandelic Acid; D006719:Homovanillic Acid