  Su et al. proposed several new classes of quaternary sequences of even length
with optimal autocorrelation interleaved by twin-prime sequences pairs, GMW
sequences pairs or binary cyclotomic sequences of order four in \cite{S1}. In
this paper, we determine the 4-adic complexity of these quaternary sequences
with period $2n$ by using correlation function and the "Gauss periods" of order
four and "quadratic Gauss sums" on finite field $\mathbb{F}_n$ and valued in
$\mathbb{Z}^{*}_{4^{2n}-1}$. Our results show that they are safe enough to
resist the attack of the rational approximation algorithm.
