Analysis of vanillylmandelic acid and homovanillic acid by UPLC-MS/MS in serum for diagnostic testing for neuroblastoma

Correlation of VMA and HVA was acceptable after adjustment of reference intervals. Collection of a single serum sample instead of 24-h urine collection saves time and improves accuracy of measurement due to difficulty of collecting a 24-h urine sample in infants and young children. UPLC-MS/MS also offers improved analyte specificity, improved signal to noise, and rapid analysis time.