Total yield of the pristine PQ (m/z = 308), an abstraction product (m/z = 294), and the superhydrogenated products (m/z = 310, 312, and 314) as a function of H-atom fluence. The yield of pristine PQ reduces with increasing exposure to H fluence. The superhydrogenated product with m/z = 314 peaks only at an intermediate H exposure. The product of abstraction, m/z = 294, dominates the mass distribution for exposure to lower H fluences and again at an exposure to high H-atom fluences.