New GLC analysis of urushiol congeners in different plant parts of poison ivy, Toxicodendron radicans.

Methods are presented for the direct GLC analysis of the catechol C15 alkenyl side-chain congeners contained in the urushiol fraction of poison ivy (Toxicodendron radicans) and the C17 homologs of poison oak (Toxicodendron diversilobum). A number of liquid phases were investigated and demonstrated varying degrees of separation. The methods developed were applied to the analysis of the urushiol fractions obtained from different plant parts of poison ivy. The effects of extraction before and after drying demonstrated tht a larger percentage of urushiol was obtained when the fresh plant material was extracted with ethanol.