Table 1. Urushiol peak identification

Peak #

-R congener

Retention  time  (min)

[M-H]-

Present in

1

C17 tetraene

15.09

339

Poison ivy

2

C15 diene

16.14

315

Skin sample

3

C17 triene

16.64

341

Poison ivy

4

C15 monoene

17.66

317

Poison ivy and skin sample

5

C17 diene

18.33

343

Poison ivy and skin sample

6

C15 saturated

20.20

319

Poison ivy and skin sample

7

C17 monoene

20.95

345

Poison ivy and skin sample