Agilent 6410 QQQ decreased sensitivity
Posted: Tue May 19, 2009 5:15 pm
Hi All, I hope I can find an answer to my problem in this wonderful forum. I have an Agilent 6410 QQQ (1.5 yo) and been experiencing low sensitivity (low response, even baselines with 3-digit abundances) lately. I routinely run formic acid (0.1%) ACN mobile phases. I didn't have this problem only 2 months back, but now the problem is persistent and I have horrible sensitivity for even 10-20ppm samples (only 10e1 sensitivity) when I used to have 10e5 response for 1ppb levels of the same analyte only 2 months ago. I have tried to clean the capillary, clean the nebulizer, sample shield, checked spray symmetry, to no avail. Could any inner hardware be the source of the problem? (skimmer, optics, detector, multiplier..??) I am in the middle of a BioEq study and feeling very depressed for the deminished sensitivity of the instrument. Can anybody try to shed some light in the right direction?? Thanks