Automatically add prefix in table column

[eluser]rafiqasad[/eluser]
I am using the table prefix feature of codeIgniter. Like my table name is ib_category, and field names are catName, description but in incerting data where there is a @ sign in category name or description, codeigniter automically add prefix to that column that is ib_catName. So the query goes wrong . How to solve that problem