Odd Pressure Profile

Discussion created by arp on May 14, 2019
Latest reply on May 16, 2019 by arp



We have a 1290 Infinity high speed pump and monitor the pressure continuously. Over the past 3 months, I've noticed a small dip in the pressure trace which has become more prominent over time (circled on image below in red). The method gradient is below; this dip corresponds with the gradient switching back to initial method conditions.  


A: 2mM ammonium acetate in 5% acetonitrile

B: Acetonitrile


Time (min):      A(%):      B(%):

0.00                  85.0        15.0

1.00                  85.0        15.0

5.00                  10.0        90.0

6.40                  10.0        90.0

6.50                  85.0        15.0

(Stoptime: 9.50 mins)


Our chromatography and quantitative results look fine--I'm mostly concerned about this being an indicator of wear on some component in the system. Has anyone seen this before?