$re = '/(?<!, |,|^)"(?!,|$)/m';
$str = '"Testing","Test123", ""Test0202" else", "Test 223 "testing" end" "Orange", "Banana", ""apple" crown", "tasty "Grapes" end"';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php