An approach combining reverse-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionization mass spectrometry (ESI-MS) was developed to analyze Urushiol congeners in poison ivy extract. The peak signatures detected in poison ivy were separated in 18 min at wavelengths 254 nm, 260 nm, and 280 nm with a gradient elution on the RP-HPLC system. The ESI-MS data confirmed the fragmentation patterns of six Urushiol congeners (C15:0-2 and C17:1-3) detected in the poison ivy extract. Recovery studies conducted with Urushiol (15:2) show recovery within ±2%, well within the recovery efficiency of ±15-20%. The validation data showed that the limit of detection (LOD) and limit of quantitation (LOQ) for Urushiol (15:2) was 0.29 ± 0.03 ppb and 0.97 ± 0.01 ppb, respectively, with a sensitivity of 0.110 ± 0.002 mAU ppb -1 . A standard addition calibration approach was used to quantify the Urushiol (15:2) content in the poison ivy extract and reveal one poison ivy leaf may contain 0.674 ± 0.025 mg/g of Urushiol (15:2).Our investigation demonstrates the quantitation of Urushiol congeners in complex mixtures. This same approach can be beneficial for analyzing other chemical components in food and different types of complex matrices.
An approach combining reverse-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionization mass spectrometry (ESI-MS) was developed to analyze Urushiol congeners in poison ivy extract. The peak signatures detected in poison ivy were separated in 18 min at wavelengths 254 nm, 260 nm, and 280 nm with a gradient elution on the RP-HPLC system. The ESI-MS data confirmed the fragmentation patterns of six Urushiol congeners (C15:0-2 and C17:1-3) detected in the poison ivy extract. Recovery studies conducted with Urushiol (15:2) show recovery within ±2%, well within the recovery efficiency of ±15-20%. The validation data showed that the limit of detection (LOD) and limit of quantitation (LOQ) for Urushiol (15:2) was 0.29 ± 0.03 ppb and 0.97 ± 0.01 ppb, respectively, with a sensitivity of 0.110 ± 0.002 mAU ppb-1. A standard addition calibration approach was used to quantify the Urushiol (15:2) content in the poison ivy extract and reveal one poison ivy leaf may contain 0.674 ± 0.025 mg/g of Urushiol (15:2).Our investigation demonstrates the quantitation of Urushiol congeners in complex mixtures. This same approach can be beneficial for analyzing other chemical components in food and different types of complex matrices.