We would like to buy an HPLC system but I do not have any experience with preparative HPLC. We aim to analyse secondary metabolites from medicinal plants, collecting the compounds and then employing structure elucidation other systems. Do you have any suggestion about preparative ones or both together, analytical and preparative for phytochemical analysis? If so, let me know the system(s)- (brand, model etc)
The use of preparative HPLC mainly depends on the amount of product you want to purify. The amounf of product to product will govern the choice of column size (the internal diameter of the column and not its length), and this will impose the flow rate. With analytical HPLC you can work up to 5 or even 10 mL./min (but keep in mind that it is not very good for the pump to work at the upper limit for a long time). For higher flow rates you must work with preparative pumps and consequently use preparative HPLC.
However, if you do not have an analytical HPLC, i would recommand you to buy one first. And thanks to the automatic injector, what you can do is to inject lower volumes (so less quantity of compound) but repeat the injection a lot of times.
Do not also forget that the softwares dedicated for analytical HPLC are not the same that for preparative ones, espacially for the collection module what is very important for purification !
For structure determination (i suppose by NMR), you do not need high quantity of compound (several mg or several tens of mg). So, indeed, an analytical HPLC may be converted to "semi prep" HPLC with columns of 1 or 2 cm internal diameter.
Otherwise, if you need to isolate sevarl hundreds of mg or several grams, i would recommand you to acquire a preparative HPLC which uses columns with internal diameter of several cm.
In our lab, we have recently acquired a preparative HPLC from Interchim with a 3 detection (ELSD, UV, RI) to work up to 250 mL/min with maximum pressure of 250 bars and to work with columns of 2 cm or more. As for the price, it is around 65 000 €.
It is also my interest but it is very expensive. it is one of the modern analytical instrument the increases the performances in this area.
Waters, Agilent, Shimadzu, Thermo, Perkin-Elmer and so many companies have prepHPLC. According to my opinion go with Waters. I have done a lot of work on Waters perpHPLC system.
But you can also go for flash chromatography. Agela, Biotage etc. companies for flash chromatography.
Gudluck
:)
Yes , You can use flash chromatography . And in my view , you can also use Agilent 1100 HPLC. And upgrade it for preparative ,the company will do it. And the same instrument can be used for analytical as well as preparative applications . There is also fraction collectors provide along with it to collect the different fractions that will be useful for the biological properties.. You can also attach the mass spectrometer attached to it and separate the required compounds as per mass of the compound and collect it as fraction.
The use of preparative HPLC mainly depends on the amount of product you want to purify. The amounf of product to product will govern the choice of column size (the internal diameter of the column and not its length), and this will impose the flow rate. With analytical HPLC you can work up to 5 or even 10 mL./min (but keep in mind that it is not very good for the pump to work at the upper limit for a long time). For higher flow rates you must work with preparative pumps and consequently use preparative HPLC.
However, if you do not have an analytical HPLC, i would recommand you to buy one first. And thanks to the automatic injector, what you can do is to inject lower volumes (so less quantity of compound) but repeat the injection a lot of times.
Do not also forget that the softwares dedicated for analytical HPLC are not the same that for preparative ones, espacially for the collection module what is very important for purification !
For structure determination (i suppose by NMR), you do not need high quantity of compound (several mg or several tens of mg). So, indeed, an analytical HPLC may be converted to "semi prep" HPLC with columns of 1 or 2 cm internal diameter.
Otherwise, if you need to isolate sevarl hundreds of mg or several grams, i would recommand you to acquire a preparative HPLC which uses columns with internal diameter of several cm.
In our lab, we have recently acquired a preparative HPLC from Interchim with a 3 detection (ELSD, UV, RI) to work up to 250 mL/min with maximum pressure of 250 bars and to work with columns of 2 cm or more. As for the price, it is around 65 000 €.
next week, a group from Shimadzu will give us a briefing about the preperative systems. As they said, they have an equipment with flow rate 100 mL/ min, it seems promising to obtain the products. Anyway, I'll share meeting notes, here very soon, if you are interested.
Thx Richard, I'll keep in mind your suggestions... In fact, this will be our first, therefore try to get one, and use continuously. I dont know time what shows me for later experiment... I may discuss the options what I have here.
For my part, i always need an analytical HPLC to check the purity of the compounds purified by preparative HPLC.
And in general, a pump efficient at 80 mL/min flow rate is not as efficient at very low flow rates (1 mL/min for instance)...
1. analytical model expandable to semiprep are available. They will do both jobs well.
2. While selecting, if you are not in any big city where servicing the instrument is not easy, pl check your surrounding labs. Buy from the maximum instrument supplier from your area. You can exchange small components, service engineers will be more willing to attend if there are more instruments of their brand around etc.
If your goal is just quantify already isolated compounds, then go for Analytical HPLC. Shimadzu LC2010 series is a good option for compact analytical HPLC.
However, if you want to isolate new compounds, I will suggest prep HPLC. No doubt it will be expensive but as you have stated in your question that you want to go for structure elucidation and things like that, I will suggest you go for Prep.
As Dr. Maringati suggested, make sure that enough and easy after sales service is available for whichever instrument you buy.
I have used Shimadzu, Agilent and Thermo HPLC/UPLC and its my personal opinion that Shimadzu systems are more robust when compared to other. But as I said, its my personal opinion, other people might differ but you can do some survey to get such info. Hope this help.
Rohitash
Thanks for your suggestions... I have decided to buy Analytical since my goal will quantfy the samples for now. Later I'll try to find a fund for flash chromatography for isolation. Of the brands, I was amid Shimadzu, Agilent and Thermo HPLC/UPLC... For that Rohitash's suggestion and mine Shimadzu Prominence model HPLC seems better, not only for price but also service here.
I will have also another question (this will be in another title in same topic) about fraction collector system connected to analytıcal HPLC.
Dear Buhara, as you said that your goal is just to quantify for now, I will suggest you go for LC201HT. Its cheaper than prominence (almost half) and robust as its a compact HPLC. Though it only comes with UV-Vis detector. Ofcourse, you can go for PDA with Prominence which is a modular system or else you can buy a LC2010HT + PDA.
http://www.shimadzu.com/an/hplc/LC2010/2010.html
1. with a little effort and patience, even with analuytical model you will be able to collect 10mg of pure compd which is sufficient for NMR and MS studies.
2. Fraction collector is useful and they are user friendly. Shimadzu is good- we used that and also Agilent.
3. Get AMC for 5yrs and spares of minimum essential components shd be procured.
You can use FCS if you don't want to bug yourself with manual collection of fractions.
Always possible to use liquid liquid extraction, or SPE, etc in place of a prep system. There is no replacement for analytical system. I am fond of Waters systems, the 515 pumps are very forgiving
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