I have a G1315C detector that fails "Lowest Intensity Test" in the 190-220 nm range (1867 counts) and the 221-350 nm range (4915 counts). All other intensity values are significantly lower than when conducted a year ago. A new Agilent lamp is installed. All measurements are with flow cell removed from the light path. They were 3000 and 7980 counts, respectively, when run 14 months ago (Dec 2018).
I plan to attempt cleaning of accessible optics as a last resort before purchasing a detector exchange unit, after consultation with Agilent technical support. The 1260 user manual notes that the glass can become contaminated with a film as time passes due to the composition of the glass.
My question is regarding the acromat (source lens) in particular. I presume it consists of several lens elements cemented together to correct for chromatic aberrations and focus light through the flow cell. (I have not removed or disassembled it yet, awaiting proper tools to do so.)
Is the optic lens cement resistant to 2-propanol? I dont want to destroy the lens as I attempt to clean it. The other windows appear to be single elements so I am not as concerned with those.
Is there another solvent such as ethanol that Agilent might recommend for gentle cleaning of the optical surfaces.