GCMSsolution

This video demonstrates how to use high pressure injection function in Shimadzu GCMS solution Let me first explain why we need to use high pressure injection or you might be familiar with the alternative name of pulsed injection instead if you are using non Shimadzu instrument. Inside the injection port in the gas chromatograph, there is a glass insert installed. The glass insert has a fixed volume depending on the dimension of glass insert used. When liquid sample is introduced into the injection port, it will get vaporized inside the glass insert. Different solvents have different solvent expansion volumes depending on the type of solvent, injection temperature, injection volume and column head pressure. Which mean how much vapor would be produced from that injection. When solvent vapor exceeds the volume of the glass insert, backflash will occur, solvent vapor containing the sample will overflow to the carrier gas line. The carrier gas line is not heated, so condensation will occur. When condensation occur, it means samples will stay in the carrier gas as a contaminant. In such a case, there is a need to increase the pressure such that solvents vapor is suppressed and not overflowing to the carrier gas line.

This video demonstrates the Automatic Adjustment of Retention Times (AART) function in Shimadzu GCMSsolution software. When a column is cut during maintenance or the method is transferred into another instrument, there may be a shift in compound retention time. Hence, there is a need to modify the retention times. Good news is that the retention index of the compounds remains unchanged when same column stationary phase and dimension is used. AART function in Shimadzu GCMSsolution make use of this property to allows adjustment of compound retention times automatically using the retention indices of the compounds and the n-alkanes retention times and retention indices.