function RemoveWhiteSpaces(const S: String): String;

var

  I: Integer;

  ch: Char;

begin

  result := '';

  for I:=1 to Length(S) do

  begin

    ch := S[I];

    if ch = ' ' then begin end

    else if ch = #9 then begin end

    else

      result := result + ch;

  end;

end;

procedure TForm1.FormCreate(Sender: TObject);

begin

showmessage(RemoveWhiteSpaces(' abc1 23 @16 3.c om '));     //结果 abc123@163.com

end;