TLC in bioanalysis

[aniket]

i am newcomer in the field of chromatography? i just have seen so many lc, lc-ms methods for bioanlysis, but very few TLC methods, i fell TLC is very good technique? then why it is not used in bioanalysis? i dont TLC should be given its due importance? please help me on this? tom sir!

[bert]

Dear Aniket,

TLC is not very suitable for quantitative analysis and it will not help you to fullfill demands from government guidelines.

Regards Bert

[Srinivas SK]

Hello

We've grown so used to high-tech, automated, "intelligent" and "modern" chromatography systems that we've forgotten our chromatographic roots.

TLC is a badly underestimated technique - and unfairly so. Instrumental TLC is just as good as any other separation methodology. It can and does meet regulatory requirements as well, which is why it still features in pharmacopoeial monographs.

TLC does have some pluses going for it and it scores over other methods, especially with herbal samples and non-volatile analytes in complex matrices. Sensitivity and resolution are comparable to HPLC, if one uses the right system and if one knows what one is doing.

Cost-per-sample is remarkably low compared to analytical HPLC. And end-user training is a lot easier - even with the latest HPTLC systems.

I've always found it a pleasure to train people on HPTLC systems. And it's a whole lot easier to get into more "advanced" forms of chromatography if one has a good understanding of TLC.

Using prep tlc one can even isolate analytes with a purity in excess of 95% - comparable to prep LC and at far lower costs.

TLC remains a valid - and relevant - separation technique, even in today's automation-dependent, regulation-bound analytical lab.

Sorry to sound like a 20th century dinosaur, but I really think TLC deserves its due in the modern lab.

It's no substitute for any other separation technique of course, but TLC can hold its own against any chromatographic system one can think of.

So much so, I feel we really need a separate TLC forum ! It certainly merits a forum of its own.

As for Aniket's query about TLC methods : Well there are perhaps as many TLC methods as HPLC methods. It's simply a matter of looking in the right place, like any other literature search.

If you have any TLC method development needs, I'd be happy to come over to your lab and help you out - as a professional.

Warm rgds

[bert]

It can and does meet regulatory requirements as well, which is why it still features in pharmacopoeial monographs.

Dear Srinivas,

I understood that Aniket is talking about bioanalysis? Do you think that is a food option? And what about selectivity/sensitivity?

Regards Bert

[Srinivas SK]

Seek and thou shalt find

Check out these links :

http://www.ncbi.nlm.nih.gov/entrez/quer ... d=16321493

http://www.ncbi.nlm.nih.gov/entrez/quer ... &DB=pubmed


Or, visit PubMed at this link and enter "TLC" or "HPTLC" in the Search window.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi


Merry XMas !

[bert]

Maybe Christmas will do the thing

Have also a nice Christmas!

[amaryl]

Hello

We've grown so used to high-tech, automated, "intelligent" and "modern" chromatography systems that we've forgotten our chromatographic roots.

TLC is a badly underestimated technique - and unfairly so. Instrumental TLC is just as good as any other separation methodology. It can and does meet regulatory requirements as well, which is why it still features in pharmacopoeial monographs.

TLC does have some pluses going for it and it scores over other methods, especially with herbal samples and non-volatile analytes in complex matrices. Sensitivity and resolution are comparable to HPLC, if one uses the right system and if one knows what one is doing.

Cost-per-sample is remarkably low compared to analytical HPLC. And end-user training is a lot easier - even with the latest HPTLC systems.

I've always found it a pleasure to train people on HPTLC systems. And it's a whole lot easier to get into more "advanced" forms of chromatography if one has a good understanding of TLC.

Using prep tlc one can even isolate analytes with a purity in excess of 95% - comparable to prep LC and at far lower costs.

TLC remains a valid - and relevant - separation technique, even in today's automation-dependent, regulation-bound analytical lab.

Sorry to sound like a 20th century dinosaur, but I really think TLC deserves its due in the modern lab.

It's no substitute for any other separation technique of course, but TLC can hold its own against any chromatographic system one can think of.

So much so, I feel we really need a separate TLC forum ! It certainly merits a forum of its own.

As for Aniket's query about TLC methods : Well there are perhaps as many TLC methods as HPLC methods. It's simply a matter of looking in the right place, like any other literature search.

If you have any TLC method development needs, I'd be happy to come over to your lab and help you out - as a professional.

Warm rgds

So much passion for TLC hmm great! Reminds of being Indian passion

Merry Christmas to all!

Amaryl.

[amaryl]

Ammendments in monograph doesn't takes place so easily. Thus, TLC will continue to stay. Evolution of life accounts for our existence so is the research to find better options humans seek convenience.

What will be the future of UPLC and OPLC in analytical labs in coming years?

Regards,

Amaryl.

[jitender]

Amaryl Wrote:

Ammendments in monograph doesn't takes place so easily.

IF you pointing to 'test of impurities' which in many Pharmacopoeia is based on TLC, it may be noted that in US Pharmacopoeia same is refered as 'chromatographic impurities' and is usually (if not always) based on HPLC analysis.

[aniket]

i agree with srinivas, call it great indian passion, or whatever, but i fell TLC is not getting its due as a analytical technique, there is one lab in mumbai called Anchrom labsoratories which is imparting free HPTLC training for students, which is very good, it is helping spread awareness of TLC, around 25 labs in and around mumbai have HPTLC, many people are using this, TLC should get what it is desrving,

thank you,

meerry Xmas

[Srinivas SK]

Hey there Aniket

I know the Anchrom people well. Nice to know my old friend Dilip Charegaonkar is still vigorously promoting HPTLC.

I'd suggest you also check out Chromline Equipment in Mumbai. They promote HPTLC systems in India, from the other major HPTLC manufacturer. My friend Rajendra Bande from Chromline is quite an authority on HPTLC and I'm sure he'd be happy to give you some good tips on HPTLC techniques.

Always a good idea to be in touch with more than one instrument vendor, especially in HPTLC ! You get a lot of useful tips that way !!

Warm rgds,

Srinivas

[aniket]

thanks shrinivas for replying,
what do you think pharmaindustry should look inot TLC as a technique? not only in bioanalytical but in other fields too? i fell it is a negected imp technique? can you please give me adress of chromline?

also i have seen in anchrom they are using HPTLC for isolation of compoensts, which is lot cheaper and easier than prep HPLC, what do u think?

thank you very much

[Srinivas SK]

Hi there Aniket

I don't want to spill the beans now, but I am working on an indigenous HPTLC development project of my own, here in Bangalore. I'll share more with the forum when I have something to talk about.

Personally, I would not choose a Camag system for prep work. I'd prefer dedicated prep tlc systems like radial flow or centrifugal tlc or optlc.

You can contact Chromline via :

www.chromlineindia.com

Chromline sells Desaga HPTLC systems in India and also represents several other chromatography companies.

A point of caution though : HPTLC is by no means a substitute for HPLC. A good prep HPLC would yield components of much higher purity as compared to prep TLC. Prep TLC is OK for around 95% purity or so. But if one is trying to isolate hi-purity reference compounds, prep HPLC is the method of choice.

An instrument dealer that sells only HPTLC systems would naturally be somewhat biased. Which is why it is always a good idea to talk to a dealer with a wider product range that includes other chromatography techniques. As a purchaser and end-user, one has to talk to several vendors and take information from varied sources.

Warm rgds,

Say hello to the Chromline boys from me.

[amaryl]

A great deal of medicinal uses has been reported for the herbs in Ayurveda.

But looking in to the present scenario of patents and guidelines we need lot of supporting data for their claims to be useful in diseases like diabetes, cancer and many other.

TLC and HPTLC holds a good promise to isolate, characterize, quantify the active constitutents. Good area of research work.

Amaryl.

[HW Mueller]

Take a look at CAMAG´s refs if you think TLC is not used much in bioanalytics.