Analysis of twenty phenolic compounds in human urine: hydrochloric acid hydrolysis, solid-phase extraction based on K2CO 3-treated silica, and gas chromatography tandem mass spectrometry

Anal Bioanal Chem. 2015 May;407(14):4131-41. doi: 10.1007/s00216-015-8598-1. Epub 2015 Apr 24.

Abstract

This study developed a new method for the analysis of 20 phenolic compounds in human urine. The urine samples were prepared by hydrochloric acid (HCl) hydrolysis, liquid-liquid extraction (LLE), and solid-phase extraction (SPE) cleanup. We found that HCl hydrolysis is of similar effectiveness to, and much cheaper than, the traditional enzymatic method. Vanillic acid was co-eluted with butyl paraben and interfered with the determination of butyl paraben in urine. K2CO3-treated-silica-gel SPE was designed to efficiently eliminate interference from the endogenous organic acids (especially vanillic acid) in urine. After derivatization, the samples were analyzed by large-volume-injection gas chromatography-tandem mass spectrometry (LVI-GC-MS-MS). Good linearity (R (2) ≥ 0.996) was established in the range 0.1-100 ng mL(-1) for all analytes. Method detection limits (MDLs) were 0.7-9.8 pg mL(-1). Intraday (n = 5) and interday (n = 5 days) validation was performed, with satisfactory accuracy (recovery: 70-126 % and 73-107 %, respectively) and precision (RSD ≤ 19 %) at two levels (low: 0.1 and 0.5 ng mL(-1); high: 5 and 10 ng mL(-1)). The method was used in a population study and achieved more than 85 % detection for most analytes; mean analyte concentrations were in the range 0.01-185 ng mL(-1). The method is suitable for the analysis of multiple phenolic metabolites in human urine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Carbonates / chemistry*
  • Child, Preschool
  • Chromatography, Gas / methods*
  • Humans
  • Hydrochloric Acid / chemistry*
  • Hydrolysis
  • Infant
  • Phenols / urine*
  • Potassium / chemistry*
  • Reproducibility of Results
  • Silicon Dioxide / chemistry*
  • Solid Phase Extraction / methods*
  • Tandem Mass Spectrometry / methods

Substances

  • Carbonates
  • Phenols
  • Silicon Dioxide
  • potassium carbonate
  • Hydrochloric Acid
  • Potassium