$re = '/TOTAL:? ?(\d+.\d+)[^\d]?/m';
$str = '4 Discover Credit Purchase - c REF#: 02353R TOTAL: 40.00 AID: 1523Q1Q TC: mzQm 40.00 CHANGE 0.00 TOTAL NUMBER OF ITEMS SOLD = 0 12/23/17 Ql:38piii 414 9 76 1G6 THANK YOU FOR SHOPPING KR08ER Now Hiring - Apply Today! TOTAL 40.0';
preg_match_all($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