Dim result = row.ItemArray.
    Skip(5).
    Select(Function(item, index) New With {.Item = item, .OriginalIndex = index + 5}).
    Where(Function(x) String.IsNullOrWhiteSpace(x.Item.ToString())).
    Select(Function(x) io_dtGatesMonitoring.Columns(x.OriginalIndex).ColumnName).
    ToList()