my @a = ( 1, 2, 3, 4, 5, 6, 7, 8 );
my @b = ( 12, 13, 1, 2, 3, 4, 22 );
my %h = map { $_ => 1 } @a;

use Data::Dumper;
print Dumper \@b;
@b = grep { ! exists $h{$_} } @b;
print Dumper \@b;