Dim myString As String = "Another Test String, Separate Strings with ""space character"""
Dim result = myString.Split(""""c).[Select](Function(element, index) If(index Mod 2 = 0, element.Split(New Char() {" "c}, StringSplitOptions.RemoveEmptyEntries), New String() {element})).SelectMany(Function(element) element).ToList()
Or use this if you still want to keep the quotes.
You will have to Import System.Text.RegularExpressions
Dim parts = Regex.Matches(myString, "[\""].+?[\""]|[^ ]+").Cast(Of Match)().[Select](Function(m) m.Value).ToList()