Missing character \ when parsing csv?

Question

PHP

I have a csv file in which some fields contain the \ character.
This file is parsed using php and the resulting data is entered into a MySQL table.

include 'connect.php';
    $table = "".$prefix."table"; 
  $handle = fopen('php://memory', 'w+');
fwrite($handle, iconv('CP1251', 'UTF-8', file_get_contents('in.csv')));
rewind($handle);
   $r = 0; 
   set_time_limit(0);
while (($row = fgetcsv($handle, 1000, ';', '"')) != FALSE) 
   {
        $r++;
      if($r == 1) {continue;} // Не дает записать в БД первую строку 
      $ins="INSERT INTO $table (`1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`) VALUES ('$row[0]', '$row[1]', '$row[2]', '$row[3]', '$row[4]', '$row[5]', '$row[6]', '$row[9]')";
      mysql_query($ins);
      if (mysql_errno()) {echo mysql_errno() . '\n' . mysql_error() . '\n';}
   }

After entering the data into the table, the \ symbols disappear (while the / symbols remain intact).
How to deal with these? Thanks in advance!
Solved the problem thanks to ILoveYAnny:
change the Msql query to

$ins=sprintf("INSERT INTO $table (`1`, `2`, `3`, `4`, `5`, `6`, `7`) VALUES ('$row[0]', '$row[1]', '$row[2]', '$row[3]', '%s', '$row[5]', '$row[6]')",mysql_real_escape_string($row[4]));

(in my case the problem was in $row[4])

Answer 1

I may be wrong, but it seems to me that PHP takes this as an escape character. Try specifying an escape before the \ , perhaps there are other ways to indicate that this is not an escape character, but character text. Mb specify in quotes.