Agilent InfinityLab LC Series Vialsamplers User Manual 173
5 Optimizing Performance  
Precise Injection Volume
Precise Injection Volume
Injection Volumes Less Than 2 µL
When the injection valve switches to the BYPASS position, the mobile phase in 
the sample loop is depressurized. When the syringe begins drawing sample, the 
pressure of the mobile phase is decreased further. If the mobile phase is not 
degassed adequately, small gas bubbles can form in the sample loop during the 
injection sequence. When using injection volumes <
 2 µL, these gas bubbles can 
affect the injection-volume precision. Use degassed mobile phases for best 
injection-volume precision with injection volumes <
 2 µL.
If the pump has no degasser, it is recommended to use an Agilent 1260 Infinity 
degasser.
Also, using the automated needle wash (see “Optimization for Lowest 
Carryover” on page 167) between injections reduces carryover to a minimum, 
further improving the injection volume precision.