  Starting from the known one-loop result for the $e^{+}e^{-}$-annihilation
process $e^{+}e^{-}\stackrel{\gamma,Z} {\longrightarrow} q\bar{q}g$ with
massless quarks we employ analyticity and crossing to determine the absorptive
parts of the corresponding one-loop contributions in Deep Inelastic Scattering
(DIS) and in the Drell-Yan process (DY). Whereas the ${\cal O}(\alpha_s^2)$
absorptive parts generate a non-measurable phase factor in the
$e^{+}e^{-}$-annihilation channel one obtains measurable phase effects from the
one-loop contributions in the deep inelastic and in the Drell-Yan case. We
compare our results with the results of previous calculations where the
absorptive parts in DIS and in the DY process were calculated directly in the
respective channels. We also present some new results on the dispersive and
absorptive contributions of the triangle anomaly graph to the DIS process.
