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

[Dan_P]

I asked Christoph about the filter. He said it’s for everything. Small particles of food, detritus, or whatever can potentially affect the reading/accuracy. The nutrient stabilizer basically freezes any microbial activity in the blue cap vial. The filter also helps to reduce most of the microbes making into the sample in the first place.

Just to clarify, the vendor filters for accuracy not the customer, right?

 

[Reefahholic]

Just to clarify, the vendor filters for accuracy not the customer, right?

Correct. They provide you with the filter and nutrient stabilizer.

 

[Dan_P]

Correct. They provide you with the filter and nutrient stabilizer.

Cool, which vendors go to this length?

 

[BeanAnimal]

We are slipping further into the abyss here I think.

OK, one experiment with 8 elements outside of a lab setting with freshly mixed saltwater that is prone to errors and contamination issues.

I wish you would not have done that (honestly) because I think you just showed the zealously driving most of your contributions to the conversation.

Yes it was 8 Elements, and none of them fared very well with regard to precision or accuracy. With that in mind, your position is that you somehow, also outside of a lab are able to discern the accuracy of another 40+ returned element values that use the same testing methods and are prone to the the same contamination or worse because you are interpreting results from random people and random tank samples from various labs.

Even with OES, reefers were still getting better results,

You missed the point. You have spent time in this thread admitting that EOS is and can be way off compared to MS.... yet before MS you were 100% trusting the the EOS results and used those to drive the same dosing methodology.

Which broken compass can be attributed to the success?

 

[Rick Mathew]

I have to say, that is one of the nicest home labs I’ve seen. I wish I had that kind of space. Are you using Eppendorf single channel pipette’s? I need to find some good cheaper ones. I can’t afford the stuff I have at work, but they are very accurate.

Kind of you to say. I have been building it for several years...Birthdays and Christmas is part of the supply chain ...I had to vacate my closet ...the local thrift store was very happy.

Every addition is directed to either enhance accuracy / precision and or make the testing easier. Keeping it well organized is inherited from my father..."If your organized you can be more effective in your work and decrease the chances of error" ...One other lesson he instilled in me was "pretty does not equal good and chaotic does not equal bad. It is the craftsman not the tools that do the work...learn and practice your craft and make it a goal to continuously get better"...Pretty good advice from my perspective.

Here are the Pipettes I use

 

[ingchr1]

We were talking about filtered ICP sample water.

I was referencing this quote. It sounded like you were talking about tank water, not sample water going into the ICP machine.

...Since all of our water is filtered, I’m guessing there’s not much benefit to unfiltered samples...

The question I have, is there benefit to the hobbyist to know how their tank water tests filtered vs unfiltered?

 

[Randy Holmes-Farley]

IMO, it's a confounding issue with ICP that folks do not know what, if anything, is filtered out, and what particulates are present but not filtered out.

I found that issue myself when testing aluminum released from phosguard. Some of the aluminum released from phosguard could be filtered out by a 0.45 um filter, and some could not. Would less have been filtered out with a larger pore filter? More with a smaller pore filter?

Interpreting the answers becomes quite complicated when we cannot distinguish soluble from particulate forms of elements.

 

[Rick Mathew]

Very clearly reasoned.

Agree!

 

[Randy Holmes-Farley]

I assume that careful studies have been done to justify the filters, but I'd also caution that analytes at low levels can be bound to filters enough to impact the values.

It may not be easy to determine if the value of, say, copper, went down on filtration because it is in a particulate large enough to be excluded, or bound to an organic molecule that attaches itself to the filter material. This is a well known problem with filtering samples prior to analysis.

We always run our controls through the same filters as samples to ensure that we are not losing analyte onto the filter, but in a case such as, say, copper in a reef tank, if we do not know what it is bound to, it is difficult to run an appropriate control.

One possible answer is to use the same filter multiple times in a row and see if the drop in an element changes. If the drop became smaller, it may be that binding is the explanation, with binding sites eventually becoming saturated, while if it stays the same, that tends to support particulate removal.

As is often the case in reef chemistry, the closer we look at something, the less clear it becomes. lol

 

[Rick Mathew]

As is often the case in reef chemistry, the closer we look at something, the less clear it becomes. lol

This is soooooooo True!

 

[ingchr1]

Cool, which vendors go to this length?

I know that ICP-Analysis and Triton only provide vials, no filter or stabilizers. My last Triton sample was a couple of years ago, in case that has changed.

This raises the following questions:

1. Does the filtering and adding of stabilizers by the customer affect the end test results? Since at least one lab has the customer do this, is it expected that that labs tests results would be different than the other labs?
2. For the eight elements tested, would an unfiltered sample of tank water test the same as a filtered sample? When running an at home test most hobbyists are not filtering their sample water. Assuming an ICP labs filters the sample water, is it expected to get different test results? All other factors aside, just from a filtering standpoint.

 

[Thales]

IMO, it's a confounding issue with ICP that folks do not know what, if anything, is filtered out, and what particulates are present but not filtered out.

I found that issue myself when testing aluminum released from phosguard. Some of the aluminum released from phosguard could be filtered out by a 0.45 um filter, and some could not. Would less have been filtered out with a larger pore filter? More with a smaller pore filter?

Interpreting the answers becomes quite complicated when we cannot distinguish soluble from particulate forms of elements.

It is also frustrating/confounding that there are no standards or best practices between reef icp/ms vendors - they all do things differently while saying they are the best, most accurate, and most precise. And no meaningful transparancy and constant changes to process.

 

[Randy Holmes-Farley]

I know that ICP-Analysis and Triton only provide vials, no filter or stabilizers. My last Triton sample was a couple of years ago, in case that has changed.

This raises the following questions:

1. Does the filtering and adding of stabilizers by the customer affect the end test results? Since at least one lab has the customer do this, is it expected that that labs tests results would be different than the other labs?
2. For the eight elements tested, would an unfiltered sample of tank water test the same as a filtered sample? When running an at home test most hobbyists are not filtering their sample water. Assuming an ICP labs filters the sample water, is it expected to get different test results? All other factors aside, just from a filtering standpoint.

FWIW, I've wondered if some of the folks with crazy high silicon are getting the value because one or more diatoms got into the plasma.

Need help with extremely high silicon.

Greetings I recently have been having issues with diatoms so I decided to serve a sample to be tested at ATI in Germany. They tested both my display task water and my rodi. Here is what is strange: the silicon readings in my RODI test sample are setup zero. Here, the silicon reading in my DT...

www.reef2reef.com

 

[taricha]

Just off the top of your head, how much do you think that would cost for the CRM? I haven’t looked yet.

heh, you wouldn't like my answer

I'm curious to see what you come up with for a quote on a seawater reference that will certify those 8 elements.

My Water Testing Lab

It's all so well organized and impressive and innovative - some stuff I know you DIY'd,
but the part that always tickles me is the bank of timers, LOL.

 

[areefer01]

Wow someone who runs the way I do (Strictly speaking on the filtration side). I do use bit of activated carbon, maybe a smidge different.

What the Berlin method? Lots of live rock and a skimmer? Many of us have been running this for years.

 

[areefer01]

Cool, which vendors go to this length?

Do you mean include a pre-filter for the hobbyist to use with their sample? I know when I tried Oceamo's ICP they included a filter. Basic rinse syringe with tank water a few times before, draw water, push through filter into sample tube, bla, bla, bla. That sort of thing.

I can't speak if they are the only one but I use ATI more often and there is no filter.

 

[areefer01]

It is also frustrating/confounding that there are no standards or best practices between reef icp/ms vendors - they all do things differently while saying they are the best, most accurate, and most precise. And no meaningful transparancy and constant changes to process.

One could argue that it is the same with additives and/or some hardware.

Hope your day is well.

 

[Thales]

One could argue that it is the same with additives and/or some hardware.

Hope your day is well.

For sure

 

[taricha]

1. Does the filtering and adding of stabilizers by the customer affect the end test results? Since at least one lab has the customer do this, is it expected that that labs tests results would be different than the other labs?
2. For the eight elements tested, would an unfiltered sample of tank water test the same as a filtered sample? When running an at home test most hobbyists are not filtering their sample water. Assuming an ICP labs filters the sample water, is it expected to get different test results? All other factors aside, just from a filtering standpoint.

1. The filtered/stabilized sample that oceamo uses is specifically for PO4. Based on storage studies by Rick over the years and data I've seen myself - it seems justified. Tank water doesn't typically hold PO4 steady for a week in a tube, unless something is done to halt biological activity. New salt water fares better, there's less stuff to drive biological activity in the tubes. Rick has demonstrated chlorination and acidification as two ways to help stabilize PO4 in tubes.

2. unfiltered vs filtered: in the narrow context of this study, filtered vs unfiltered will make little difference as this was mixed saltwater that had been prepared just for these purposes, all the things we looked at were well-soluble, and we checked that there was little loss during our storage for 7 days locally, and it's not live tank water with the potential for cells and detritus.

But in general with live tank water, I've messed around with running liters of tank water through filters and analyzing what gets left behind on the filters. It's not really enough to care about for most situations I can imagine. Specifically, For the 8 elements tested, Ca, Mg, K, - major ions dissolved in water far outweigh tiny dustings of particulates.
PO4 never seems to care much in my tank water whether I filter or don't (but a few others using La, or I guess having significant carbonate dust in the water find that filtering changes their hanna PO4 result). Iodine same. Fe, when I run GFO - the particulate Fe is not zero - I can see GFO dust collect in the skimmer, and this is likely far higher than the soluble Fe in the tank water.

Just as a thought experiment, consider what happens when you put live seawater in a tube, some cells will grow. If you could make sure those cells didn't stick to the tube and they all went into the plasma, then everything those cells pulled from the water would show back up in the ICP report and it would measure the same as if those cells had never grown at all - it would reflect your water at sampling time. But if you filter out those cells at the lab, then whatever the cells pulled from the water would be missing from the ICP - relative to what was in the tube at the time you sampled it.

 

[BeanAnimal]

IMO, water changes are too inconsistent and you loose precision. They also cause a destabilizing event every time you do one unless you have AWC’s setup. If I do a water change, it takes the tank a while to get back to the same stability, and growth it was getting before the change.

This sounds like sales rhetoric to me. Your entire body of work in this thread is predicated on a precision that simply does not appear to be available. That is my basic sticking point and hasn't changed with your supporting responses.

It feels more like faith than science and I can't get past that part.