Hi All, I recently discovered a command to load a standby method at the end of a single run automatically in Openlab Chemstation and wish to share with you guys.
Practically any gas chromatography systems should have the oven set up at an elevated temperature when they are not in use. This is to avoid any moisture being present in the carrier gas from deteriorating the column stationary phase, for example AL2O3 PLOT columns in refinery gas analysis (method UOP539) or hydrocarbon separation in liquefied petroleum gases (method ASTM D2163). The impact would be a significant change in retention times.
On another hand at the end of a single run or sequence the initial condition of a method is usually loaded to the gas chromatograph. Particularly any gas chromatographs starting at sub-ambient temperature, i.e. ASTM D7169 at -20oC, require the use of a cryogenic liquid (liquid carbon dioxide or liquid nitrogen). That means if the user forgets to set the oven temperature to higher at the end of his analysis it would consume a lot of cryogenic liquid.
Agilent Technologies has included a special command in Openlab Chemstation to call out the so-called standby method which helps turn the gas chromatograph to a conservative condition. Below are the steps to do so:
1. Create your own STANDBY.M method (you can name it in any ways you want).
2. Go to “Method and Run Control”, load your analysis method, access to “Method” from the top menu and select “Run Time Checklist” (Figure 1).
3. Check the box “Post-Run Command/Macro” and enter LOADMETHOD “Path to your method”,”your standby method”. For example LOADMETHOD “C:\Chem\1\Methods\”,”STANDBY.M” (Figure 2)
4. OK and save your method.
5. The method is ready to be used for your sample analysis. Once the run is done the STANDBY.M method will be called out automatically.

Figure 1

Figure 2