Triton vs Aquaforest ICP-OES

[jsker]

Triton took just a little over a week, AF about a month.

Thank you for the reply

 

[hpeti]

ICP-OES (or AES) can be complicated to interpret.

I have run it myself on my own (well, my company's) machine. There is not always just a single answer from a single run of a single sample. I was doing it with much more careful oversight of the actual data than I'm sure any analysis company does, and this was my comment in one case:

http://reefkeeping.com/issues/2005-04/rhf/index.php

from it:

"For initial testing I chose to use as the "standard" a sample of artificial seawater that was mixed to an approximate salinity of S=35. I mixed a 44-gallon batch using Instant Ocean artificial salt mix and reverse osmosis/deionized (RO/DI) water to a conductivity of 52.7 mS/cm, and allowed it to settle for three weeks. I then proceeded to measure its calcium concentration by ICP-AES (inductively coupled plasma-atomic emission spectroscopy, an $80,000 analytical instrument. I was somewhat disappointed with my inability to use this sophisticated technique to get a precise answer. Despite taking five different samples and analyzing them at eight different emission wavelengths using two different calibration methods (five standard additions of known calcium concentrations to each sample, as well as comparison to a fixed 1000 ppm commercial calcium standard), I was unable to get consistent values. Some of the samples were acidified or filtered through submicron filter membranes to determine if solid materials were impacting the result (they were not). Overall, I took more than 200 measurements, each involving three replicate observations of the emission intensity. Nevertheless, the result was not very satisfying, with a substantial variation occurring between the different values. The average of every measurement taken was 336 ppm. With the uncertainty involved, however, I'd conclude that the true value was probably 340 ± 40 ppm. I also measured the same sample once with a Salifert brand test kit and got 330 ppm calcium."

Randy, Thank you so much for the link, very informative. After reading your article I checked my logs as I also tested a few parameters of the same sample using my basic test kits. My one time calcium measurement was 460 ppm (Salifert).

 

[Jamie7907]

As a fellow reefer I would like to gauge people's interest in this testing. If you could get this same testing done here in the U.S. with a quicker turn around time and for around $15 per test how many people would be interested? Would a monthly subscription service be of interest? I was thinking something like up to 4 tests a month for one flat rate say $50-$60 or buying tests as a package? Let me know your thoughts.

 

[hpeti]

Is there any available info what the minimum amount of an element that has to be present in the sample to show up on the ICP test?

 

[jason2459]

Is there any available info what the minimum amount of an element that has to be present in the sample to show up on the ICP test?

You can download Triton's limits of detection (LOD) here: http://www.triton-lab.de/en/products-services/downloads/

 

[hpeti]

You can download Triton's limits of detection (LOD) here: http://www.triton-lab.de/en/products-services/downloads/

Thank you for the link. I think I downloaded the same version a while back, still trying to understand how to interpret that data...

 

[Randy Holmes-Farley]

Thank you for the link. I think I downloaded the same version a while back, still trying to understand how to interpret that data...

The way to interpret it is that any value that is at or below the LOD (use the higher one if a range is given) can be any value between 0 and the LOD number. In some cases, natural levels are below the LOD, so this test cannot quantify natural levels.

 

[hpeti]

The way to interpret it is that any value that is at or below the LOD (use the higher one if a range is given) can be any value between 0 and the LOD number. In some cases, natural levels are below the LOD, so this test cannot quantify natural levels.

Randy, Thank you for the clarification, I wasn't sure why the LOD was reported in ranges.

MANGANESE / Mn

LOD : 0.116 ppb - 0.384 ppb Calibration MAX : 360 ppb Correlation coefficient : 0.99986

I always thought that I would have manganese showing up on my test when the concentration in above 0.116 µg/L...
So this range would mean that I can have no manganese detected on the test but the sample could have a concentration anywhere between 0.00-0.384 µg/L?

 

[hpeti]

How should I interpret the following data for example?

CALCIUM / Ca

LOD : 0.05 ppm - 0.5 ppm Calibration MAX : 600 ppm Correlation coefficient : 0.99994

 

[Randy Holmes-Farley]

I am not sure why it is reported in ranges either, but probably depends on what other elements are present at what concentration since there can be interferences. I'd assume the higher value since they do not say for any particular test result.

 

[hpeti]

I am not sure why it is reported in ranges either, but probably depends on what other elements are present at what concentration since there can be interferences. I'd assume the higher value since they do not say for any particular test result.

Thank you for your help! It's starting to make some sense to me now, but can't say I'm not confused anymore

 

[hpeti]

Just looked at my last 13 Triton test results on manganese for example, it all shows zero. It was a relief to see some detected on the AF test as I've been dosing manganese daily for over a year now...

 

[Randy Holmes-Farley]

Here's my interpretation of that same result for my tank:

http://www.reefedition.com/my-triton-testing-results-by-randy-holmes-farley/
Manganese (Mn). Triton can just barely detect the natural level of manganese (0.17 µg/L) since their LOD is 0.12 µg/L. Detecting none suggests it may be depleted, and is another possibility for dosing, but I have less confidence that this one is really seriously depleted since it is so close to the LOD. But Mn is biologically important and I will consider it.

 

[hpeti]

Thank you! I'm not targeting natural seawater levels or any specific numbers, especially with trace elements. I can totally accept the limitations of these tests, but it's still a lots of fun to learn more about the small details...

 

[Aaron Gustafson]

As a fellow reefer I would like to gauge people's interest in this testing. If you could get this same testing done here in the U.S. with a quicker turn around time and for around $15 per test how many people would be interested? Would a monthly subscription service be of interest? I was thinking something like up to 4 tests a month for one flat rate say $50-$60 or buying tests as a package? Let me know your thoughts.

I'd be interested to know more.