Is it possible to If statement “article already appears on page”?

You can simply build an array of ID’s of posts from the loops and then just exclude those posts from the following set of queries

I don’t know your exact structure, but here is a very basic idea (Requires PHP5.4+ due to short array syntax ([]), for older versions, change back to old array syntax (array()))

// Define the variable to hold posts 
$remove_duplicates = [];

// define and run our first query
$args1 = [
    // All your arguments for this query
];
$loop1 = new WP_Query( $args1 );
if ( $loop1->have_posts() ) {
    while ( $loop1->have_posts() ) {
    $loop1->the_post();

        // Build our array of ID's to exclude from other query
        $remove_duplicates[] = get_the_ID();

        // Rest of your loop

    }
    wp_reset_postdata(); // VERY VERY IMPORTANT
}

// Define our second query and exclude posts from the first
$args2 = [
    'post__not_in' => $remove_duplicates, // Remove posts from from $loop1
    // All your arguments for this query
];
$loop2 = new WP_Query( $args2 );
if ( $loop2->have_posts() ) {
    while ( $loop2->have_posts() ) {
    $loop2->the_post();

        // Rest of your loop

    }
    wp_reset_postdata(); // VERY VERY IMPORTANT
}