Leveraging supported liquid extraction and automated workflow for high efficiency and high quality clinical LC-MS/MS method for quantification of urinary 5-hydroxyindoleacetic acid (5-HIAA), vanillylmandelic acid (VMA) and homovanillic acid (HVA)

Background and aims: 5-hydroxyindoleacetic acid (5-HIAA), vanillylmandelic acid (VMA) and homovanillic acid (HVA) are neurotransmitter metabolites used for the diagnosis and monitoring of neuroendocrine tumors. This study's objective was to apply automation to improve efficiency and quality of a liquid chromatography tandem mass spectrometry (LC-MS/MS) procedure for quantification of 5-HIAA, VMA and HVA in human urine.

Methods: 5-HIAA, VMA and HVA in urine samples were extracted with automated supported liquid extraction (SLE) and quantified by LC-MS/MS utilizing scheduled multiple reaction monitoring (MRM). An in-house developed middleware was used to automate data analysis and reporting.

Results: The average recovery for 5-HIAA, VMA and HVA in different types of urine matrix varied between 92.5 % and 99.0 %, while the average matrix factor varied between 98.6 % and 103.4 %. The results of other validation studies: stability, sensitivity, analytical measurement range, selectivity, accuracy, precision, dilution verification, carryover, and method comparison all met the performance criteria.

Conclusions: Automated SLE is a suitable sample preparation technique for quantification of 5-HIAA, VMA and HVA in human urine. Workflow automation described in this study resulted in 54 % of overall time savings and 80 % of hands-on time savings compared to all manual approach.