Here an example using map and grep

#!/usr/bin/perl

use strict ;
use  warnings ;

my $file1 = shift;
my $file2 = shift;

open(IN,$file1) || die "Cannot open file $file1 $!\n";
my $content ;
{ local $/ ;
  $content = <IN>
}
close IN ;

open(IN,$file2) || die "Cannot open file $file2 $!\n";
my @list = <IN> ;
close IN ;

my @new = grep($content !~ /$_->[0]\n/, map( [split(/,/, $_)], @list )
+) ;

foreach( @new ) {
  print $_->[0] . " " .$_->[1]  ;
}
[download]

Cheers
LuCa