According to the above definition, a two-dimensional separation system employs two separate and independent columns. We might find such a multidimensional separation system comprised of LC with GC. They are independent experiments. But for two GC columns, they may be housed in either a single GC oven or two ovens. The interface is located between – or near the join of – the two columns. We revisit this concept later. But by this definition, simply linking or directly coupling two
columns together is not a multidimensional system.