you are doing it wrong just feed the ppas as nice separate params, without these quotes spanning everything.
$1 = ppa:something/somethingCode:addit ppa:something/something ppa:something_else/something_else ppa:etc_app/etc_app
$2 = ppa:something_else/something_else
$3 = ppa:etc_app/etc_app
"$@" will take them one by one which is what you wanted to achieve with word splitting on single continuous $1. The difference is $@ way is the proper one