Provided are plasma processes for producing graphene nanosheets comprising injecting into a thermal zone of a plasma a carbon-containing substance at a velocity of at least 60 m/s standard temperature and pressure STP to nucleate the graphene nanosheets, and quenching the graphene nanosheets with a quench gas of no more than 1000 C. The injecting of the carbon-containing substance may be carried out using a plurality of jets. The graphene nanosheets may have a Raman G/D ratio greater than or equal to 3 and a 2D/G ratio greater than or equal to 0.8, as measured using an incident laser wavelength of 514 nm. The graphene nanosheets may be produced at a rate of at least 80 g/h. The graphene nanosheets can have a polyaromatic hydrocarbon concentration of less than about 0.7% by weight.

Provided are plasma processes for producing graphene nanosheets comprising injecting into a thermal zone of a plasma a carbon-containing substance at a velocity of at least 60 m/s standard temperature and pressure STP to nucleate the graphene nanosheets, and quenching the graphene nanosheets with a quench gas of no more than 1000 C. The injecting of the carbon-containing substance may be carried out using a plurality of jets. The graphene nanosheets may have a Raman G/D ratio greater than or equal to 3 and a 2D/G ratio greater than or equal to 0.8, as measured using an incident laser wavelength of 514 nm. The graphene nanosheets may be produced at a rate of at least 80 g/h. The graphene nanosheets can have a polyaromatic hydrocarbon concentration of less than about 0.7% by weight.

A plasma torch assembly (e.g., for an ICP-MS or ICP-AES instrument) with a retractable injector is disclosed. In implementations, the torch assembly includes an injector that can be extended or retracted relative to an auxiliary gas tube of the torch assembly. The injector can be slidably coupled to a torch body that supports the auxiliary gas tube, such that the injector can be moved forward and backward through a passage of the torch body, causing it to extend/retract relative to the auxiliary gas tube.

Methods and systems that can use a gas comprising a nitrogen center that is introduced upstream of a plasma sustained in a torch are described. In some configurations, the gas comprising the nitrogen center can be introduced as a gas upstream of the plasma and through a sample introduction device. Mass spectrometers and optical emission systems that can use the gas comprising the nitrogen center are also described.

Methods and systems that can use a gas comprising a nitrogen center that is introduced upstream of a plasma sustained in a torch are described. In some configurations, the gas comprising the nitrogen center can be introduced as a gas upstream of the plasma and through a sample introduction device. Mass spectrometers and optical emission systems that can use the gas comprising the nitrogen center are also described.

Provided are plasma processes for producing graphene nanosheets comprising injecting into a thermal zone of a plasma a carbon-containing substance at a velocity of at least 60 m/s standard temperature and pressure STP to nucleate the graphene nanosheets, and quenching the graphene nanosheets with a quench gas of no more than 1000 C. The injecting of the carbon-containing substance may be carried out using a plurality of jets. The graphene nanosheets may have a Raman G/D ratio greater than or equal to 3 and a 2D/G ratio greater than or equal to 0.8, as measured using an incident laser wavelength of 514 nm. The graphene nanosheets may be produced at a rate of at least 80 g/h. The graphene nanosheets can have a polyaromatic hydrocarbon concentration of less than about 0.7% by weight.

Provided are plasma processes for producing graphene nanosheets comprising injecting into a thermal zone of a plasma a carbon-containing substance at a velocity of at least 60 m/s standard temperature and pressure STP to nucleate the graphene nanosheets, and quenching the graphene nanosheets with a quench gas of no more than 1000 C. The injecting of the carbon-containing substance may be carried out using a plurality of jets. The graphene nanosheets may have a Raman G/D ratio greater than or equal to 3 and a 2D/G ratio greater than or equal to 0.8, as measured using an incident laser wavelength of 514 nm. The graphene nanosheets may be produced at a rate of at least 80 g/h. The graphene nanosheets can have a polyaromatic hydrocarbon concentration of less than about 0.7% by weight.

A conductive rod body is embedded in an insulative torch adapter into which a plasma torch is fitted so that a leading end protrudes from its outer circumferential surface. Further, a metal plate member electrically connected to a cable line to which a voltage for plasma ignition is applied is attached to a lower holder, and a conductive leaf spring member having a V-shaped cross section is attached to an upper holder. When the torch adapter is placed on the lower holder so that the protruding part of the rod body faces upward and the upper holder is closed to tighten a draw latch, the rod body and the metal plate member are electrically connected via the leaf spring member, and a high voltage for ignition can be applied to the plasma torch.

A conductive rod body is embedded in an insulative torch adapter into which a plasma torch is fitted so that a leading end protrudes from its outer circumferential surface. Further, a metal plate member electrically connected to a cable line to which a voltage for plasma ignition is applied is attached to a lower holder, and a conductive leaf spring member having a V-shaped cross section is attached to an upper holder. When the torch adapter is placed on the lower holder so that the protruding part of the rod body faces upward and the upper holder is closed to tighten a draw latch, the rod body and the metal plate member are electrically connected via the leaf spring member, and a high voltage for ignition can be applied to the plasma torch.

Disclosed herein are devices, systems and methods of use of an improved liner for a plasma torch. In particular, a segmented liner for use in a plasma torch (e.g., annular torch, swirl torch) is provided. In general, the improved segmented liner has improved thermal shock resistance capabilities over conventional unitary liners.