Development of a candidate reference method for the simultaneous quantitation of the boar taint compounds androstenone, 3α-androstenol, 3β-androstenol, skatole, and indole in pig fat by means of stable isotope dilution analysis-headspace solid-phase microextraction-gas chromatography/mass spectrometry

Anal Chem. 2011 Sep 1;83(17):6785-91. doi: 10.1021/ac201465q. Epub 2011 Aug 15.

Abstract

The steroidal pig pheromones androstenone (5α-androst-16-en-3-one), 3α-androstenol (5α-androst-16-en-3α-ol), and 3β-androstenol (5α-androst-16-en-3β-ol) as well as the heterocyclic aromatic amines skatole and indole, originating from microbial degradation of tryptophan in the intestine of pigs, are frequently recognized as the major compounds responsible for boar taint. A new procedure, applying stable isotope dilution analysis (SIDA) and headspace solid-phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) for the simultaneous quantitation of these boar taint compounds in pig fat was developed and validated. The deuterated compounds androstenone-d(3), 3β-androstenol-d(3), skatole-d(3), and indole-d(6) were synthesized and successfully employed as internal standards for SIDA. The new procedure is characterized by a fast, simple, and economic sample preparation: methanolic extraction of the melted fat followed by a freezing and an evaporation step allows for extraction and enrichment of all five analytes. Additional time-consuming cleanup steps were not necessary, as HS-SPME sampling overcomes fat-associated injector and column contamination. The method has been validated by determining intra- and interday precision and accuracy as well as the limit of detection (LOD) and limit of quantitation (LOQ). Additionally, a cross-validation for androstenone, skatole, and indole was carried out comparing the results of 25 back fat samples obtained simultaneously by the new SIDA-HS-SPME-GC/MS procedure with those obtained in separate GC/MS and high-performance liquid chromatography fluorescence detection (HPLC-FD) measurements. The cross-validation revealed comparable results and confirms the feasibility of the new SIDA-HS-SPME-GC/MS procedure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / chemistry*
  • Androstenes / analysis*
  • Androstenes / isolation & purification
  • Androstenols / analysis*
  • Androstenols / isolation & purification
  • Animals
  • Calibration
  • Deuterium / chemistry
  • Gas Chromatography-Mass Spectrometry / methods*
  • Gas Chromatography-Mass Spectrometry / standards
  • Indoles / analysis*
  • Indoles / isolation & purification
  • Isotope Labeling
  • Skatole / analysis*
  • Skatole / isolation & purification
  • Solid Phase Microextraction / methods*
  • Solid Phase Microextraction / standards
  • Swine

Substances

  • Androstenes
  • Androstenols
  • Indoles
  • androst-16-en-3-one
  • indole
  • Skatole
  • Deuterium