How to know if a field(First Name, Last Name, Email, etc...) a pre-defined value already exists?

How to know if a field(First Name, Last Name, Email, etc...) a pre-defined value already exists?

Hi,

I use the API Methods (https://www.zoho.com/crm/help/api/api-methods.html) to do integration with some client site and I need to know exists some field with the pre-defined value in the Contacts.

I use the getRecords Method and check the returned list, check field by field and this is so much heavy for my aplication.

So now I trying to use the getSearchRecordsByPDC Method to search the values in the "Nº CPF" fields in Contacts, but I'm not getting

What is the solution to this case?