These replacement Thermo Scientific Outer Tubes for our ICP-OES Ceramic D-Torches are made from a durable, ceramic material derived from silicon nitride, which is resistant to chemical attack. These properties are maintained at high temperatures and therefore avoid the problem of devitrification associated with traditional quartz torches. When needed, quartz replacement outer tubes are also available for the D-Torch. Improve ICP-OES plasma torch lifespan by switching to a Ceramic D-Torch.