Seawater analysis

[flipperaust]

Im not a scientific guru but wanted to know Is there an all in one Scientific sea water analysis unit for testing of all common elements that are vital in reef keeping. Trying to avoid titration or photometer units.
So start with basics of calc, alk, mg, no3, po4, iodine, strontium, potassium, iron etc then into the more untested elements.
I understand the cost of a unit would be high but wonder if someone can point me into the right direction.
Cheers

[Randy Holmes-Farley]

I'm not familiar with such a grouping. In general, if you aren't looking for a photometer, then such a product would just be a bunch of kits collected together.

I also do not think you need to measure all of those, and do not think any kits are suitable for testing iron in seawater at the levels expected.

You can send samples out to a lab, such as www.enclabs.com

[flipperaust]

Thanks for the reply Randy. I would like to discuss my reasons for the question a little further but in private if possible. You will understand why
Thanks

[UVvis]

Honestly, no.

Even with more advanced instrumentation, there isn't a do it all that you'll find in an oceanography/limnology lab.

There are so many different instruments and analysis methods available, each with an area or two that they really specialize in.

On top of that, some of the heavy metals are very difficult to analyze for directly with the seawater matrix. All the sodium, magnesium and calcium really have a high loading to see through. This is where some preconcentration techniques for AA, GFAA, and ICP-MS instruments come into play.

There are some spectrophotometer/photometer/colormeteric methods that are often used for some of the more common ions, like phosphate, nitrate, nitrite, ammonia/ammonium, silicates and a couple others. Often in flow injection and discreet analyzers.

Many titrations are perfomed for alkalinity and dissolved oxygen, the calcium and total hardness chelation titrations are pretty good for Ca and Mg numbers.

Ion Chromatography is another good option for many of the cation/anion counds.

Sometimes folks with move to instruments with NDIR detectors for organic/inorganic carbon. Shimadzu makes some good ones that can add a chemiluminescent total nitrogen detectors that give results comparible to total kjehldahl nitrogen methods. Sometimes you'll have elemental analyzers that use catalytic oxidation methods for total nitrogen/carbon in particular matter.

Then you have flourometers and related turbidity instruments for particular pigments, sometimes HPLC extrations will be used too for different photopigment populations.

So basically, there really isn't an all in one unit that can target the ideal ranges of even the more common things out there.

Go figure.

[flipperaust]

Thanks UVvis,
Was looking at a way that i could offer accurate lab quality testing so reefers can compare these results with their own test kits to gauge accuracy. Obviously it would take various pieces of equipment to get the range or testing required.
Was just a thought but looks like it maybe more complicated than i thought.
Cheers

[disc1]

Mass Spectrometry baby.

[UVvis]

Mass Spectrometry baby.

:)

Even then your ionization methods and matrix effects do not work well in seawater. There are other instruments that outperform MS systems for a many analytes, and with lower overall cost pricetags.

Mass Spectroscopy is just another tool in the bag, and what we want is a bag full of tools.

[gypsyboy38]

Ha, took the words out of my mouth uvvis. Can't count the number of times I've run a sample on the ICP-oes instead of the ICP-ms because of matrix issues... I usually don't bother with the ms unless someone is interested in an element with poor emission intensity.

[Randy Holmes-Farley]

:thumbsup:

Nice to have a bunch of chemists around. :)