Problems with strings copied from a spreadsheet

Question

I have a system that uses the Codeigniter framework, this system has some fields that the user uses to register things... The user copies some phrases that are standard of a spreadsheet of Libre Office, and this data that the registered user is registered in my system, and through a Web Service is registered in another system, the problem is that the Phrase Appears there all right type: "Black Disposable Cup"but when I use a part of the system that serves to search for something that was registered according to this phrase the system does not recognize the whitespace and I can not search the register that was made.

I know that Libre Office spreadsheets use UTF-8 encoding, our systems and the files we have use "ISO 8859-1" encoding, so I tried to use a solution that was to decode Phrase for another encoding, but it didn’t work out and sometimes there is an error saying that I’m using an illegal karate, see below what I tried to do:

function decodeStringAuto($str, $decode = 'ISO-8859-1//TRANSIT') {

  $str = iconv(
      mb_detect_encoding($str, mb_detect_order (), true),
      $decode,
      reduce_multiples($str, ' ', true)
  );

  return $str;
}

I have tried several alternatives I searched on the internet but I could not solve the problem, someone has an alternative to it ?