Serializing Data Without Class

Hello everyone and thanks for your help in advance.  I am developing a WebApi2 application.  I am working with an external class library that returns object data like:
Person.FirstName, Person.LastName, etc.  In WebApi examples, the way lists are returned is:
persondetail.Add(New Person With {.FirstName = reader("FirstName").ToString), However, I am not exactly sure how to add data to a list without are reader.  I tried:
Dim PersonDetails As New List(Of KeyValuePair(Of String, String)) PersonDetails.Add(New KeyValuePair(Of String, String)("FirstName", Person.FirstName)) but this doesn't seem to return the data correctly.  The end use is a jQuery population of a web page.  Any help would be appreciated.  Thanks.