Hi,

Sorry, no way to measure such species directly with a simple spectrophotometer.

Specific electrochemical or optical sensors can be used for in-situ measurements for some of your species. You can use X-Ray fluorescence techniques which is moderatly invasive for P, S, Ca, Mg, K, Na but needs a  rather expansive equipment and also specific method development.

With colorimetry, you can measure most of these ions with a minimum of equipment but it uses reagents. If you can buy equipment, you may consider HPIC (high performance ionic chromatography) or ICP-OES (Ok for S and P but you will not measure ammonium nor carbonate). For metals, flame atomic absorption/emission is also an option, you can find low cost instruments on the market (used for about US$ 1000) and switch it in emission mode to spare lamps. Nowaday it will use also reagents such as nitric acid, lithium and lanthane (for matrix stabilisation).

Unfortunately, there is no hope to perform your analyses for free.

Dear Frenkel,

you may want to search for the term "ion sensitive electrodes". If money is an issue but time and patience is not, it may even be an option to build them on your own?..

Good luck!

Holger

Dear Frankel,

Have you considered the use of ion chromatography.  It is a relatively straightforward technique and does not require the mentioned ions to be derivatised, and can be relatively inexpensive.  In addition, it is a pretty sensitive technique, where sensitivities may be enhanced by the use of an appropriate column/s, sample pre-concentration and the optimum instrument parameters.

Please find attached, application notes which cover examples of the mentioned analytes.

If you do decide to obtain an ion chromatography system, do consider one which is modular, easy to install and use and maintain, and robust.  In that way extra modules, such as detectors, autosamplers, post column reactors, etc., may be added at any stage, to accommodate your future requirements.

Kind regards,

Ade Kujore

Marketing

Cecil Instruments Limited

Milton Technical Centre, Cambridge CB24 6AZ

United Kingdom

email:- [email protected]

telephone:- +44 (0) 1223 420821

fax.:- +44 (0) 1223 420475

web site:- www.cecilinstruments.com

Spectrophotometry is generally molecular spectrometry method, which we may measured (quantify) molecules present in the solution (their concentrations). Metalic ions and some anions are analogues of atoms, so we have to use methods of atomic spectrometry (AAS, OES and ICP-MS). If we wanted to determine ions by molecular spectroscopy methods we have to convert them to the appropriate molecules (reactions with specific reagents) and use their absorption in the relevant region of the spectrum. As a non-destructive method for measuring elements and ions could be used X-ray fluorescence spectrometry method with some limitations of this method.

The only ion you can determine with direct spectrophotometric detection is nitrate. It has a very high UV absorbance (below 250 nm) and if there isn't much organic matter in the water, the spectrometric method can be very accurate.  If there is a lot of organic matter, some corrections are necessary, but they may be unreliable if the absorbance of the OM is very high relative to the nitrate.  Iron may also interfere.  Here is one link:

https://books.google.com/books?id=tZEAAAAAQBAJ&pg=PA287&lpg=PA287&dq=direct+detection+nitrate+spectrophotometric+standard+methods&source=bl&ots=hkA91NDzUt&sig=Y1tMxFckoSHfXaEYuA-h2_ch6tY&hl=en&sa=X&ved=0ahUKEwih4J6n8rDJAhWEaz4KHVtGBOgQ6AEINTAD#v=onepage&q=direct%20detection%20nitrate%20spectrophotometric%20standard%20methods&f=false

Dear colleagues,

Thanks a lot for your answers. Feedback in every topic is always inspiring.

My request specifically dealed with the possibility of using specific reagents at least as possible and developing techniques as soon as possible with the infrastructure at my hand: a spectrophotometer UV-visible, a conductimeter (conductivity, TDS, % salinity) and a pH meter (pH and voltage).

In the other hand, I realise that cooperation between labs is always required until financing. Open to collaborations and advices,

Kind regards, Frenkel

Dear Ade,

I downloaded all the files you attached to me. Useful information that I will consider when planifing coming projets for ecotoxicology studies in freshwater ecosystems near human settlements.

I sent an application to Rockefeller foundation for funding in this topics. If accepted I´ll contact you. Have in mind if equipment can be shipped to Cuba. Answer me soon.

Kind regards, Frenkel

Dear Frenkel,

Thank you for your response.

Do you have an email address through which I can send you further information.  I look forward to hearing from you.

Kind regards,

Ade Kujore

Marketing

Cecil Instruments Limited

Milton Technical Centre, Cambridge CB24 6AZ

United Kingdom

email:- [email protected]

telephone:- +44 (0) 1223 420821

fax.:- +44 (0) 1223 420475

web site:- www.cecilinstruments.com

Dear Ade,

Of course you can send additional information and keep in contact through [email protected]

University E-mail account does not allow entry of attachement higher than 3.5 Mb at should not overpass 10 Mb each day. Keep this in mind.

Regards, Frenkel

Na and K are  analyzed by flame photometer;Calcium and total calcium plus magnesium are analysed by EDTA titrimetric methods using the indicator of Patton and Reeder, and Eriochrome Black T, respectively. The difference between

the two titrations gave the magnesium content in the sample. Calcium and magnesium contents were also verified by using a new indicator developed in our laboratory . Bicarbonate and carbonate contents are analysed by titration with hydrochloric acid using methyl orange and phenolphthalein as indicators. Chloride content are  analysed by titration with silver nitrate using potassium chromate as indicator. Sulphate  is  measured by visual comparison of turbidity with closely

matching standards using barium chloride as precipitant, pH and conductivity by pH-meter and conductivity meter, respectively. Kindly go through the cited references in this publication.

Article Interpretation and evaluation of the variations in uranium, ...

Conference Paper New indicator for titration of calcium and total calcium plu...

Article Indicator for the titrimetric determination of calcium and t...

Article Spectrophotometric determination of nitrite in water

Dear Charles,

Thanks for your feedback. It's an interesting book. Do you have it downdoaled?

Regards, Frenkel

Dear D.P.S. RATHORE,

Thanks for your support. Articles and books are very valuable. I´ll check it this week-end for selecting possible methodologies that I could use soon.

Regards, Frenkel

Sorry, I do not.  There is a link to the standard methods here,

http://www.mwa.co.th/download/file_upload/SMWW_4000-6000.pdf http://www.mwa.co.th/download/file_upload/SMWW_4000-6000.pdf

The method is under "Ultraviolet Spectrophotometric Screening Method"

There are some more interesting papers on water analysis related with uranium.

Article Letter to the Editor: Comments related to the publication by...

Article Letter to the Editor: Comments related to the publication ti...

Article Comments on Uranium Concentration in Groundwater in Hisar City, India

Article Letter to Editor : Query related to publication titled “A co...

Article Letter to HERA's Editor Concerning the Article “Risk Assessm...

Article Letter to Editor : Geochemical modeling of uranium speciatio...

Dear Tareq,

Could you send me some of the articles you mentioned above? I need procedures for calculating ions concentration when using conductometry or potentiometric methods, essentially those commonly encountered in urban, industrial and domestic wastes.

Thanks