Inorganic ions analysis by HPLC

[zanio]

Hi my name is Ana. I am new in field of chromatography science and I am glad that this forum exist.

I have a question? What is the application of HPLC in analysis of inorganic ions in soil?

Thank you!

[Gerhard Kratz]

Kurzmitteilung Bestimmung von Dicyandiamid, Nitrit und Nitrat in Bodenextrakten mit Hochdruckflüssigkeitschromatographie
K. VilsmeierArticle first published online: 12 JAN 2007

DOI: 10.1002/jpln.19841470215

Copyright © 1984 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


Determination of dicyandiamide, nitrite and nitrate in soil extracts by high pressure liquid chromatography

A method for simultaneous determination of dicyandiamide, nitrite and nitrate in soil extracts and percolation water by means of HPLC has been developed. Extraction is done with water or CaCl2, followed by separation on a RP–C18 column with tetrabutylammonium hydrogen sulfate and sodium dihydrogen phosphate as mobile phase UV-absorbance is measured at 220 nm. Detection limit is 0.1 mg N/I.

Or IEX chromatography. You can start with the following conditions:
Column Hamilton PRP X-100, 10 mm anionexchange
column, 150 mm 3 4.1 mm
Injection volume 20 ml
Flow rate 2.0 ml min21
Mobile phase 10 mM PO4
32, pH 6.0, isocratic
Good luck

[zanio]

Thank you for the reply. I'll try with HPLC variant.
May I ask another question?
Can I carry out analysis of anions on conventional HPLC sistem with anion exchange column? Can I use conventional sistem for ion chromatography?
In the lab we have got Agilent 1200 liquid chromatograph, quaternary pump , autosampler, degasser and UV-DAD detector.
What anion could be determined with UV detector? -bromide,iodide,thiosulphate, nitrate,nitrite , ciano metalic compounds?

[Gerhard Kratz]

Yes you can use your Agilent HPLC system, but sensitivity will be not as good as with a dedicated IC system from Metrohm or Dionex. UV is possible for most of the anions, but detection will be at 190-200nm, or 210nm or 230nm.

[Markus Laeubli, Metrohm]

Another possibility would be indirect UV detetction. Using and anion exchange column and a phthalic acid eluent. Detecting at the phthalate absorption will lead to so called vacency peaks for ions which do not absrob at that wavelength.
Its an alternative for HPLC, but as Gerhard mentioned not as sensitive as with IC.
You also neeed to be aware that the HPLC System should be passivated prior to use. Otherwise components from the system may harm the column and or complex ions of interest.

[zanio]

Besides ion chromatography , can I use ion pair reagents on RP HPLC column , because we haven't got IC sistem?
What do you think about this possibility?

Thank you!

[Markus Laeubli, Metrohm]

you definitely can give it a try.
I have no experience in this field as I am working with ion exchange columns. In the beginning also on HPLC systems.

[Gerhard Kratz]

Please be aware that ion pair reagents will modify the surface of your column packing material. Extremely difficult to remove that. Indirect UV detection I would try first.

[Consumer Products Guy]

Can I carry out analysis of anions on conventional HPLC sistem with anion exchange column? Can I use conventional sistem for ion chromatography?
In the lab we have got Agilent 1200 liquid chromatograph, quaternary pump , autosampler, degasser and UV-DAD detector.
What anion could be determined with UV detector? -bromide,iodide,thiosulphate, nitrate,nitrite , ciano metalic compounds?

All depends upon your matrix, and sought-for anion levels. We routinely use an Agilent 1050 or 1100 system for this with a conductivity detector, detect anions and organic acids. Mostly we pre-make mobile phase and bypass the quad pump mixing valve to get a smoother baseline (like we do when we use refractive index detector).

If you matrix is clean, you might even be able to use low UV as posted above. There are specialty anion columns and organic acid columns readily available for these.

[zanio]

Thank you !

May I ask you last question? Can I determine simultaneously cations( Ca2+, Mg2+, K+,) and anions in one run by IPC?

[Markus Laeubli, Metrohm]

I assume that you ask for anions and cations by IC.
Here the answer is no. There have been a few columns where the manufacturer did claim to be able to run anions and cations simultaneously. But I never saw a system for real samples.

It is possible to run anions and cation in parallel by using a dual channel system.

[oscarBAL]

Hi zanio; as far as I know there is no way to determine cations and anions together by IPC.
I used to Analyze NO3, NO2, SO4 and even Total Nitrate after pesulfate dijestion in Saples from aquaculture ponds by IPC using DAD and C18; the results were quite good for my porpuse I would say that even better than conventional spectrophotometric determination by color generation; can you imagine how dirty my samples were???
The problem as Gerhard mentined you will need a dedicated column for that and stabilization time in my case was longer; As a learning experience was very good; but if you can Buy a IC column then go for it!! and if you can get an IC even better.

Coming back to the cation analysis I do not know what your limits of detection are and how many samples you will analysis but try to have in mind what other option are; if price is an issue I think a flame photometer could do the job (not to much sencible for Calcium emmsion as far as I remember) avery basic instrument could be arround $15K; or if you have a good pH meter you could also explore ISE potentiometry.


Hope this help

[zanio]

Thank you of all for the responses!

Let me to explain my idea . In our lab we make soil analysis of nutrition elements by so called wet chemistry. These are time consuming and low sensitive methods. Since 2 years ago we bought Agilent 1200 with UV DAD.
And than I ask myself if could be make this analysis on HPLC. In literature I found more ways for determination these compounds, such as IC, spectrophotometric , ICP ( for metals) and other. I know that IC is more power technic for these kind analysis, but we haven't got this sistem. Than I had readed one article for simultaneously determination of cations and anions by IPC UV. This had attracted my attention and becauce I haven't more expirience in this field I have desided to ask this qouestion. Here is a link http://www.springerlink.com/content/j128g60h7v2hh560/ of the article.

Regards!!!!! Ana

[H.Thomas]

May I ask you last question? Can I determine simultaneously cations( Ca2+, Mg2+, K+,) and anions in one run by IPC?

The only way to simultanouesly determine anions and cations that I have heard of, is with zwitterionic columns.
http://chromatographyonline.findanalyti ... ail/624005
http://www.esainc.com/docs/spool/70-876 ... ection.pdf
http://www.ncbi.nlm.nih.gov/pubmed/19772722

It uses a chraged aerosol detector, I'm not sure if it would work with UV.

BTW: we are also analyzing nutrients in soil - we use CFA-Autoanalyzers (Bran+Lubbe, now SEAL) for N,P,K, AAS for Mg and Ca, and IC for S.

[HW Mueller]

I have not seen the article of the last link given by H.Thomas, but the other two don´t look like all of this was simultaneous, but rather overlayed (different chromatograms were overlaid). As mentioned before, I have done some extensive experiments, using radioactive ions, and comparing a ZIC-HILIC with a Atlantis silica column. Presently, I don´t want to say more than that my impression is: the links may refer to methods which are not general.