I do not understand your question. HPLC and "Methods" are two different things. We create HPLC "Methods for use in chromatography. It does not matter if they are for use on a Prep or Analytical system as they are still called methods.

If you need an analytical HPLC (for 99.95% of most applications) for routine analysis and method development (flow rates 0.010 to 10 ml/min), then for best result use or purchase an analytical HPLC. Flow rate ranges are just one of many differences between the two. Prep HPLC systems have pump heads with huge dwell volumes (to pump large amts of liquid), use very large diameter tubing, bigger columns and are biased toward high flow rates from 20 ml/min to several hundred mls/min. While some companies do/did offer Prep systems which could be used for semi-prep and even some analytical runs (e.g. Delta Prep 4000 system), they were all very poor for analytical purposes. The large dwell volume of the Prep heads and large ID tubing means huge gradient delays and diluted samples. *Hybrid systems which allowed users to swap the prep heads for analytical ones still had to change out all of the tubing and detector's flow cell too. Prep and Analytical HPLC system are very different systems with different needs and hardware.  Prep systems can also be equipped with many of the same features and modules (i.e. Column Heaters, AutoInjectors, UV/VIS Detectors, Fraction Collectors) as analytical systems, but again, they are for very different purposes (Prep are for separating and purifying large amounts of material; Analytical systems are for developing methods to separate and quantify small amounts of material). Under normal operations, a Prep system is used with an analytical system to check purity of fractions. Only buy/use a Prep system if you need those capabilities and please do not buy/use it if your main application is an analytical one.

You wrote: "I've heard Prep HPLC has limitation of sensitivity." This terminology does not make sense. In Prep LC, you normally have huge amounts of sample so you are intentionally reducing the detector sensitivity in most methods so it does not saturate the detector. Sample quantity, chemical properties (e.g. strong or weak chromophore?),detection method used and quality of method used determine sensitivity for all methods on any type of HPLC system.

Summary: We do not recommend using a "Preparative HPLC" system for analytical HPLC methods. Prep HPLC systems have huge dwell volumes which are incompatible with the low flow rates and small columns used in analytical gradient HPLC.

Dear Dr Seongho Jeon,

Could you please explain your question again? Probably me or someone else can help.

Best regards

Aly

My question is simply, Can I use prep HPLC as just HPLC?

typical HPLC system, I mean, pumping like low rate(0~1ml/min) and high pressure (~1000psi), heating column(~60~70oC), and data from UV or RID detector)

If I understand correctly whether on not you can use a prep HPLC for analytical work depends on your particular instrument.  If you can stably achieved flow rates for analytical columns then it should be fine.

Dear Seongho,

yes you can use prep HPLC for analytical works.

BUT you have to remember that in chromatography all dead volumes are fundamentals (for gradient elution and for resolution) and must be reduced in order to maximize the resolution. Additionally also the detector dead volume is important for the same reason.

For your applications you can check the back-pressure. In HPLC with analytical column. Generally the prep HPLC support the back-pressure (check the manual before) generally observed in HPLC (approx. 1000 to 2000 psi).