  By studying quantum information masking in non-Hermitian quantum systems, we
show that mutually orthogonal quantum states can be deterministically masked,
while an arbitrary set of quantum states cannot be masked in non-Hermitian
quantum systems. We further demonstrate that a set of linearly independent
states which are mutually $\eta$-orthogonal can be deterministically masked by
a pseudo-unitary operator. Moreover, we study robustness of quantum information
masking against noisy environments. The robustness of deterministic and
probabilistic quantum information masking under different quantum noise
channels is analyzed in detail. Accordingly, we propose and discuss the
$r$-uniform probabilistic quantum information masking in multipartite systems.
