Chromatography Forum

Question: Are there any "high performance" UV detectors out that there are significantly better than the mainstream models available? By better, I mean a 30% or better S/N ratio for peaks that are riding close to the method LOQ, at a typical wavelength of 210 nm. Reason for this is that we have a trace impurity method under development that is close to the goal of a LOQ of 5 ppm, but needs that extra little "push" to build in ruggedness and "safety". We've already run out of all of the usual "tricks" to lower the method LOQ (such as sample concentration, injection volume, fixed wavelength versus diode array, pre-mixing the mobile phase solvents, changing detector slit widths, time constants, flow cells, column and particle size, flow rates, etc, etc.), but would be highly interested to know if there is a unique UV detector out there that is a "superstar" - even if from an obscure vendor.
Thanks.
/posted on behalf of my colleague/

At 210 nm, the limit in sensitivity is more often related to the mobile phase, and much less to the detector capability.

Although I agree with Uwe, I kind of remember of a "superstar" UV, where they were using superior optics and re-focusing techniques to increase the S/N. I do not remember anymore the brand name (I thought it was Jasco, but I took a quick look in their site without noticing something).

Although I do not remember the claimed increase in sensitivity, I remember that their UV was about 2 fold more expensive (which might led to it discontinuation...).

My impression is that the "arms race" on UV detectors ended in a stalemate. The only non-standard one I'm aware of is Thermo's 10-cm path-length cell. I believe there is patent protection on the internal reflectance technique they use, so it will probably be a one-of-a kind for the next few years.