44
Optimizing Performance
Fast Injection Cycle and Low Delay Volume
Fast Injection Cycle and Low Delay Volume
Short injection cycle times for high sample througput is one of the main
issues in analytical laboratories. Shortening cycle time starts with:
•
shortening column length
•
high flow rate
•
steep gradient
Having optimized these parameters, further reduction of cycle times can be
obtained using the overlapped injection mode.
Overlapped Injection Mode
In this process, as soon as the sample has reached the column, the injection
valve is switched back to bypass and the next injection cycle starts but waits
with switching to mainpass until the actual run is finished. You gain the
sample preparation time when using this process.
Switching the valve into the bypass position reduces the system delay
volume, the mobile phase is directed to the column without passing sample
loop, needle and needle seat capillary. This can help to have faster cycle
times especially if low flow rates have to be used like it is mandatory in
narrow bore and micro bore HPLC.
N O T E
Having the valve in bypass position can increase the carry-over in the system.
The injection cycle times also depend on the injection volume. In identically
standard condition, injecting 100 µl instead of 1 µl, increase the injection time
by approximately 8 sec. In this case and if the viscosity of the sample allows
it, the draw and eject speed of the injection system has to be increased.
N O T E
For the last injection of the sequence with overlapped injections it has to be
considered that for this run the injection valve is not switched as for the
previous runs and consequently the injector delay volume is not bypassed.
This means the retention times are prolonged for the last run. Especially at
Summary of Contents for G1313A
Page 1: ...s1 Agilent 1100 Series Standard Micro and Preparative Autosamplers Reference Manual ...
Page 3: ...Reference Manual Agilent 1100 Series Standard Micro and Preparative Autosamplers ...
Page 12: ...12 Contents ...
Page 39: ...2 2 Optimizing Performance How to optimize the autosamplers to achieve best results ...
Page 93: ...93 Troubleshooting and Test Functions Step Commands ...
Page 216: ...216 Introduction to the Autosampler Electrical Connections ...
Page 244: ...244 Theory of Operation The Main Power Supply Assembly ...
Page 265: ...265 Introduction to the Control Module Diagnostics and Tests ...
Page 268: ...268 Introduction to the Control Module Diagnostics and Tests ...
Page 274: ...274 Specifications Performance Specifications ...
Page 275: ...10 Legal Safety and Warranty Information ...
Page 286: ...286 Agilent Technologies on Internet ...
Page 290: ...290 Index ...
Page 291: ......