Repeated Sample RSD failures

[djones82]

Using a very robust (and simple) HPLC method that works constantly on other machines on a Waters Alliance HPLC I keep getting erroneous injections or typically high sample RSD's. The system has been OQ'd and PM'd very recently and passed all the basic points on this but still suffers from these failures. There is a new lamp fiitted too. Occasionally I experience the "plunger over pressure" error code but would this have any bearing?

I am a novice.....please help!!

[DR]

Plunger over pressure error is certainly worth investigating.
Without more information about your samples and solutions in use, there's not much more we can offer.

[Consumer Products Guy]

Plunger over pressure error is certainly worth investigating.

Always fix first what you KNOW is bad.

See above.

[juddc]

What CPG said...Did you PQ the system post PM? A plunger overpressure error definitely isn't right.

[Johnny Rod]

What is a "high" RSD? Waters injectors aren't as precise as others