HOBBY GRADE TEST KITS CAN OUTPERFORM ICP MEASUREMENTS…REALLY??

[Christoph]

@Lasse

With this - do you mean a purchased Certified Reference Material? Not done in your Lab?

Yes, a certified reference material bought from the European Comission. We are reporting how we use this material for internal quality control here

Correctness and repeatability of ICP-MS seawater measurements

Hello Everyone! This is a „takeout“ from the reef moonshiners thread, which can be found here: https://www.reef2reef.com/threads/moonshiners-method-feedback.996193/ One point raised in this thread is that quality from seawater labs is often seen with a lot of skepticism. I would like to quote...

www.reef2reef.com

and here

ICP-MS measurement of Seawater Certified Reference Material

Dear Reef2Reefers! I have seen a lot of skepticism regarding seawater laboratory analysis in this forum, especially when in comes to reported values for trace elements. I must say, that all skepticism is very well justified, since there is many potential pitfalls in ICP analysis: Sampling...

www.reef2reef.com

All the best,
Christoph

 

[Dan_P]

Hello everyone,

maybe this is a good point to add some precision/accuracy data for the analyte copper (Oceamo ICP-MS seawater analysis) here. Data is based on triplicate measurement of three different concentration levels in seawater matrix based standard on 3 different measurement days. In addition data from a CRM that was measured on on 18 consecutive days (but not in triplicate, only one datapoint per day).

This is "typical" data and not automatically valid for all samples. As i have outlined before many aspects influence signal, so for example in very high salinity samples lower accuracy/precision is to be expected.

Copper
Method: ICP-MS

Mean accuracy @ 1 ppb: 108,33 (±2,62)% (9 Measurements split over 3 days)

Mean accuracy @ 5 ppb: 103,70 (±5,87)% (9 Measurements split over 3 days)

Mean accuracy @ 10 ppb: 95,62 (±2,72)% (9 Measurements split over 3 days)

Mean accuracy @ 0,87 ppb: 109,28 (±13,3)% (18 Measurements on 18 consecutive days, CRM data)





I hope this is helpful!
best regards,
Christoph

Thanks for sharing this information Christoph.

Is the percent accuracy correlated with three standard deviations?

While this data is an example how well your analytical device works, it still does not address the question of what precision the customer can expect because of the long time between sampling and analysis and uncontrolled storage conditions between sampling and analysis. So, the important question is whether you have duplicated these results with samples that you mailed to yourself and which then sat in the queue waiting to be tested?

 

[Randy Holmes-Farley]

Thanks for sharing this information Christoph.

Is the percent accuracy correlated with three standard deviations?

While this data is an example how well your analytical device works, it still does not address the question of what precision the customer can expect because of the long time between sampling and analysis and uncontrolled storage conditions between sampling and analysis. So, the important question is whether you have duplicated these results with samples that you mailed to yourself and which then sat in the queue waiting to be tested?

Such a test should include freezing since that may be an unavoidable aspect of shipping in winter, and has the potential to mess with element concentrations as the residual liquid gets more and more concentrated.

 

[Dan_P]

@Rick Mathew, Thursday roughly marks when all discussion was suspended. All quiet and time for reflection I guess.. It would be interesting to have ChatGPT have a go at summarizing our 43 pages of discussion.

 

[Dan_P]

@Rick Mathew, Thursday roughly marks when all discussion was suspended. All quiet and time for reflection I guess.. It would be interesting to have ChatGPT have a go at summarizing our 43 pages of discussion.

@Rick Mathew, Just had a chat with ChatGPT and it did not know that a $50 ICP-OES test was available, let alone that hobby test kits are competitively accurate for some chemical species. The AI noted that it was trained with information up to 2021. I did not point out that ICP’s were avaiable since 2016.

 

[Randy Holmes-Farley]

@Rick Mathew, Just had a chat with ChatGPT and it did not know that a $50 ICP-OES test was available, let alone that hobby test kits are competitively accurate for some chemical species. The AI noted that it was trained with information up to 2021. I did not point out that ICP’s were avaiable since 2016.

Wow, pretty big knowledge gap for an internet trained AI.

 

[Garf]

ICP’s were avaiable since 2016.

I thought these were out 11 or 12 years ago through triton when I was messing around with algae scrubbers. Perhaps I’ve got my timeline mixed up, lol. I would have thought they had perfected them by now, to be honest.

 

[Rick Mathew]

@Rick Mathew, Just had a chat with ChatGPT and it did not know that a $50 ICP-OES test was available, let alone that hobby test kits are competitively accurate for some chemical species. The AI noted that it was trained with information up to 2021. I did not point out that ICP’s were avaiable since 2016.

I have seen this response from ChatGPT a number of time before...

 

[Rick Mathew]

@Rick Mathew, Thursday roughly marks when all discussion was suspended. All quiet and time for reflection I guess.. It would be interesting to have ChatGPT have a go at summarizing our 43 pages of discussion.

Seems so...

 

[Dan_P]

I thought these were out 11 or 12 years ago through triton when I was messing around with algae scrubbers. Perhaps I’ve got my timeline mixed up, lol. I would have thought they had perfected them by now, to be honest.

Well, yeah, at least my Bio-AI got closer than ChatGPT

 

[Dan_P]

Wow, pretty big knowledge gap for an internet trained AI.

I thought the same thing. Maybe if paid for a better version, the gaps would be smaller.

I wonder whether training AI has parallels with training children minus the child’s propensity to glom onto all sorts of other data at the same time.

 

[Reefahholic]

I thought these were out 11 or 12 years ago through triton when I was messing around with algae scrubbers. Perhaps I’ve got my timeline mixed up, lol. I would have thought they had perfected them by now, to be honest.

Triton was already testing water before 2014. So at least 10 years ago.

 

[Christoph]

Such a test should include freezing since that may be an unavoidable aspect of shipping in winter, and has the potential to mess with element concentrations as the residual liquid gets more and more concentrated.

Here you go, Randy :


Original: Sample measured within 60 min after taken from a reef tank
8 day room temp: Sample stored 8 days at room temperature (~19-22°C) prior to analysis
7 days -20°C, 1 day room temp: Sample stored for 7 days in the freezer (-20°C) and one day at room temperature prior to analysis

All samples taken at the same time in triplicate and also analyzed in triplicate (individual tubes).
Analysis performed: Oceamo ICP-MS seawater analysis

All the best,
Christoph

 

[Rick Mathew]

Here you go, Randy :


Original: Sample measured within 60 min after taken from a reef tank
8 day room temp: Sample stored 8 days at room temperature (~19-22°C) prior to analysis
7 days -20°C, 1 day room temp: Sample stored for 7 days in the freezer (-20°C) and one day at room temperature prior to analysis

All samples taken at the same time in triplicate and also analyzed in triplicate (individual tubes).
Analysis performed: Oceamo ICP-MS seawater analysis

All the best,
Christoph

Christoph, looks like we don't have to worry about stability of copper during transport. Thanks for sharing... Nice work

 

[ingchr1]

There are also other reasons to not use them. I sent in a sample and got my RODI results, but the results for my tank remained in pending status. I contacted them several times inquiring about it but never got resolution. They responded to my initial emails, but after that they never responded back.

As an update on this, they (ICP-Analysis.com) did end up contacting me. My sample or results were lost, wasn't clear which one. They sent me a replacement test kit.

 

[Dan_P]

Christoph, looks like we don't have to worry about stability of copper during transport. Thanks for sharing... Nice work

39 elements to go

 

[Rick Mathew]

39 elements to go

That would be the idea!....very valuable!

 

[Randy Holmes-Farley]

Here you go, Randy :


Original: Sample measured within 60 min after taken from a reef tank
8 day room temp: Sample stored 8 days at room temperature (~19-22°C) prior to analysis
7 days -20°C, 1 day room temp: Sample stored for 7 days in the freezer (-20°C) and one day at room temperature prior to analysis

All samples taken at the same time in triplicate and also analyzed in triplicate (individual tubes).
Analysis performed: Oceamo ICP-MS seawater analysis

All the best,
Christoph

Nice! Thx.

 

[Lasse]

Here is my results from 12 test send from Sweden to Austria (normal 5 days transport) during winter, spring, summer and fall for three years. I have take away all that I dose (Alk, Mg, Ca, Sr,Fe, Va, I, Mn, B and F) and all known residues/uptake from other processes (Al Si and Ba) I dose Ru until 23-01-18 after that no dosing of Ru. I have used Red Sea blue in order to withhold salinity until 23-01-18. No major WC. Between 23-01 18 and 23-02-18 I did change around 30 % of the water - using OCEAMO´s controlled, liquid salt Oceamo Corrector. it is the only salt I use for the moment. I change around 0.6 L saltwater a day (replaces water losses from KH director)

These figures tell me that ICP testing is rather reliable - its not much variation (or spread) in the tests of the compounds. During this time I have only feed with frozen food

If I do a similar of all of my over 20 tests since 2016 I have done with help of Triton I get a similar sets of result - variations - yes but they are small in µg/l.

Sincerely Lasse.

 

[rtparty]

39 elements to go

39+

Don't foget it is 40+ elements we get to know when testing with ICP compared to home kits.

40.

Plus.

Dan.