3.2. Juvenile hormone extraction, purification and quantification by GC-MS
JH has principally been quantified using one of two procedures, radioimmunoassay (RIA) or gas chromatography-mass spectrometry (GC-MS), where mass spectrometer is the quadrupole mass spectrometer, herein referred to by the trade name "Mass Selective Detector" (MSD). Generally, the GC-MSD approach purifies extracted JH III, then converts it to a d3-methoxyhydrin derivative prior to quantification. This technique was initially developed by Bergot et al. (1981), modified by Shu et al. (1997), and adapted for use in honey bees by Amdam et al. (2010). For further protocol details on GC-MS applications in honey bee research see the BEEBOOK paper on chemical ecology (Torto et al., 2013). The major advantage of this protocol is its high resolution, providing the capacity to quantify significant differences between relatively small quantities of the hormone. Its major limitations are the time necessary to process samples, its relatively high cost, and having to maintain sensitive equipment.