HPLC or UHPLC?

[adrs211]

I work with a company which is trying to upgrade their Lab. They don’t have any analytical instrument at the moment. I have not worked with any UHPLC system is the past, but it seems that they are becoming more popular. I am wondering if it would be better to invest on a UHPLC system rather than a HPLC system! Our main work would be on development of stability indicating assays for semisolid dosage.

[XL]

Depending on the nature of analysis and budget limitqation, a "HPLC" system may satisfy your needs in most cases. However, it makes more sense to consider buying LC systems that are compatible with both UHPLC and HPLC applications. For your purpose, such UHPLC/HPLC system is appropriate. Agilent, Thermo and Waters are offering such systems with some differentiations. You will need to contact the local sales person from all three companies for more details.

[nonagon]

You must consider your application/s, as there are many which are not (yet?) compatible with UHPLC.
- There are very few columns for large molecules.
- Refractive index (RI) detectors are not available for UHPLC (CAD is the only current replacement).
-In a regulated environment (USP, EP), going from HPLC to UHPLC is OK but not the the other way around.
- Do you have high throughput to justify UHPLC (maybe try semiporous/nonporus columns on HPLC).
In addition to what XL said most new "off the shelf" HPLCs can allow >600bar.
I am working with a HPLC/UHPLC hybrid and would not reccommend it as a starting kit.
In short: go for a good new HPLC and contact column supplier for applications for your analytes. Add UHPLC when throughput trumps costs.