THere is no HPLC oxidant detector, but you can detect compounds that have this property and others if you have a detector for the others. There is also an amperometric detector which allows to detect compounds possessing redox properties (must be 'tuned')

Hi, Francisco, yes, ypu can use HPLC for determination of contents of low molecular weight antioxidants and its redox.

You have to extract your materail in MPA and you can u8se HPLC for determination of reduced and total ASC/GSH. Fhr total contents you have to use DTT tretaent before loading to HPLC. Good luck!,

THere is no HPLC oxidant detector, but you can detect compounds that have this property and others if you have a detector for the others. There is also an amperometric detector which allows to detect compounds possessing redox properties (must be 'tuned')

Yes u can use DPPH or ABTS online HPLC methods for the estimation of antioxidant activity by using HPLC.

The negative peaks of antioxidant compound present in the extrcat gives u a view about the presence of antioxidants in it.

You can use HPLC-DAD with gradient system for determination of contents of antioxidant chemicals among the crude or fractionated extracts of medicinal plants. UV-visible Spectrophotometric method is best for antioxidant activity tests in different methods

Yes you can use HPLC for this purpose. However, you should identify the components which having this property. There is no HPLC unit with oxidant determination.

Concerning spectrophotometric methods, you can associate UV-visible and electrochemistry (potentiostat) to analyze the antioxidant potential of your metabolites. It is really interesting if you want to measure the oxidation kinetics of your extracts.

Using HPLC, amperometric detector is the best way. Firstly, you can detect compound family depending on the measured current related to your selected potential (interesting if you want to remove certain metabolite families when working on a total extract from plants). Then you can analyze the redox properties of your metabolites and highlight their capabilities to cope with reactive species.

This detector can be also associated to LCMS to optimize the determination of natural products!

if you pass a standard (for example caffeic , cinnnamic, benzoic acid ...) you can see if your mixture contains these compounds or not, the best is to do GC/MS and LC/MS

of course, You can use HPLC with PDA detector for determining antioxidants. You can use many kinds of column such as: C8, C18 or Ph column. With mobile phase: organic Solvents (methanol or ACN) with actate buffer or phosphat buffer ( pH 3 - 4.5) with brandy or gradient programe!

In which the matrix?

The best way to determine antioxidant compounds in food, edible plant, medicinal plant [crude/fractionated extracts (water, methanol, ethanol, acetone, ethyl acetate extracts)] with LC-MS/MS. If the extracts are n-Hexane, DCM, Chloroform extracts, you can use GC-MS to quantify polyphenolic compounds. You can see a lot of these type of papers in Food Chemistry Journal.

Dear Valdebenito, I use spectrophotometry and fluorimetry. I can not tell you whether you can use HPLC.

Sincerely,

For antioxidant activity test in different methods you can use spectrophotometry and fluorimetry but for antioxidant compounds determination from extracts you have to use HPLC or LC-MS/MS or GC-MS.

I agree with Hemayet

You may determine the antioxidant component in HPLC but not the activity

Why do you want to use the HPLC? To learn the technique? Or is there a problem with the spectrophotometric method that you want to overcome? If you want to characterize the roots more accurately you should use a technique that is orthogonal (unrelated) to the anti-oxidant activity.

Qualitative and quantitative HPLC methods are described for the analysis of mixtures of twelve antioxidants. For identification of the components present, gradient elution with a convex profile from 35:65 v/v water-methanol to pure methanol is used, on a Waters 5 mum C(18) Resolve column, with an ultraviolet detector. Propyl gallate and methyl p-hydroxybenzoate cannot be separated, however. For quantitative analysis, with ultraviolet and electrochemical detectors in series, the 35:65 water-methanol mixture or pure methanol is used as the eluent, under isocratic conditions, with lithium perchlorate as supporting electrolyte. An applied potential ranging from +0.8 to + 1.7 V allows detection of all the antioxidants tested. Both modes of detection are very sensitive, with limits of detection as low as 61 pg (UV, methyl p-hydroxybenzoate) and 360 pg (electrochemistry, butylhydroxyanisole).

You may determine the antioxidant component in HPLC but not the activity. For antioxidant activity test in different methods you can use spectrophotometry and fluorimetry

You can do HPLC-DAD assay for antioxidants

In general, spectrophotometry and fluorimetry are enough for determine antioxidant activity. However, it depends on the amount of antioxidants. If there is a few amount in microgram range, HPLC may be suitable for quantify. Spectrophotometry and fluorimetry are simple and reliable instruments when you do validate method.

You can use HPLC to identify antioxidants. One thing you have to be careful is while selecting your mobile phase and running protocol.

Using a developed method you can separate more than 20 antioxidant standard compounds in one run of HPLC-DAD with gradient system and different wavelength. Then you can quantify amount of antioxidant compounds present in your extract or in different fraction of extracts by comparing to area of standard antioxidant compounds.

HPLC technique coupled with MS can be used to identify potential components that may contribute to high antioxidant activity.

Its depends on compounds, in case of phenols and naphthols you can use HPLC with UV detectors, for amines use GCMS with FID.

Phenols also very easily can be detected by GCMS-FID.

The polyphenolic compounds can be easily analyzed by LC-MS.

You can determine antioxidant activity by using an HPLC system with post-column on-line antioxidant detection based on 2,2’-azinobis-3-

ethylbenzothiazoline-6-sulphonic acid / DPPH radical scavenging activity.

I suggest to use HPTLC, being the method more useful to obtain the whole figure of the constituents of different types. After the separation the antioxidant can be specifically revealed

There are several option to determine qantity and quality of antioxidants in the sample. GLC or GLC with programmed increase in the temperature, both equipped vith FID, may be useful in case of relatively good volatibility and thermostability of the measured sample. In case of thermall instability or very high boiling temperature of the compounds analysed it is convenient to derivatize them via alkylation /phenols, polyphenols or amines/ or acetylation etc. GC-MS combination is another but more expensive option.

As for HPLC / DAD with variabile vawelength or electrochemical one, it is a convenient choice in the case of sollubile antioxidants. Isocratic or better, gradient

course of analyses may be used /depending on analysed antioxidants, polarity of the column and properties of mobile phase. Derivatization prior to some analyses might improve the resolution.

I agree with the comments of Rastislav Solar

Hossain,

thanks.