Chromate | Analytical Services | USA

[Chromate]

So sample prep is dilute and shoot for potential AAS adulterant in an supplement oil / synthol oil or AAS adulterant in capsule / tablet?

The data shared above gives good indication of instrument precision and operator precision for a dilution (method precision if sample prep is just dilution and injection).

For the above example, each sample was prepared by a single usage of a calibrated pipette and volumetric flask (from a stock solution). Many other samples are prepared just like this.

Some have a more simple preparation, such as peptides and certain oral supplements, requiring only a single usage of a volumetric flask.

Others are more complex, requiring 2x pipettes and 2x volumetric flasks. In which case you can compound the error shown above (after subtracting instrument error).

Powdered samples uniquely require the use of an analytical balance, introducing another form of measurement error.

 

[readalot]

For the above example, each sample was prepared by a single usage of a calibrated pipette and volumetric flask (from a stock solution). Many other samples are prepared just like this.

Some have a more simple preparation, such as peptides and certain oral supplements, requiring only a single usage of a volumetric flask.

Others are more complex, requiring 2x pipettes and 2x volumetric flasks. In which case you can compound the error shown above (after subtracting instrument error).

Powdered samples uniquely require the use of an analytical balance, introducing another form of measurement error.

Yes thank you. For my interests I'm addressing specifically the potential AAS adulterants in an oil or tablet / capsule and the methods / sample prep to quantify them.

Let me denote that as JN1 or Job Number 1 for an HPLC qualitative/quantitative test at Meso University.

 

[readalot]

instrument error

And just so we are on the same page, I am addressing | we are addressing questions on precision currently although this touches on accuracy as well. So I'd prefer to use the term instrument precision above when referring to the RSD obtained from injecting 10 reps of same sample.

 

[Chromate]

And just so we are on the same page, I am addressing | we are addressing questions on precision currently although this touches on accuracy as well. So I'd prefer to use the term instrument precision above when referring to the RSD obtained from injecting 10 reps of same sample.

Certainly. That was the intended term.

 

[nightprowler7]

So far chromate is looking like a good domestic testing facility. Would like to see more double blind comparison tests though

I'll probably use them again

 

[Ateam2023]

i wish they tested hgh though

 

[Ateam2023]

then that would be a good testing factor if only they tested hgh

 

[Ateam2023]

then that would be a good testing factor if only they tested hgh

as well as other oils

 

[DarkStalker]

What can they test exactly ?

 

[Fattyone]

What can they test exactly ?

Very first post. Click the link.

 

[UncleBuns]

Looks like my sample went MIA. I'll send another through a different courier and update when results are received.

 

[Ateam2023]

Mia? Was it the vendors fault or the mail courier?

 

[Chromate]

i wish they tested hgh though

Many new tests in development. Stay tuned.

Mia? Was it the vendors fault or the mail courier?

Either arriving late, or lost, unfortunately.

@readalot Apologies for the late submission.

A short analysis of the data collected here.

Instrument precision (right column), RSD:
First 2 injections: 0.077%
First 3 injection: 0.194%
First 6 injections: 0.251%
All 7 injections: 0.262%

USP Guidelines:



For n=3 we are 50% below the maximum permitted RSD, and for n=6: 70% below.

Interestingly, where instrument RSD increases as number of injections increases, method RSD decreases with repeat dilutions.

Method precision (left column), RSD:
First 2 dilutions: 1.52%
First 3 dilutions: 1.13%
First 6 dilutions: 1.10%
All 7 dilutions: 1.05%

Of course, this is not representative of a full method because no quantification was performed here. It is also difficult to extrapolate onto a full method because such errors are unlikely to perfectly reinforce one another.

Based on this data, it appears it would be of more value to prioritize single injections of multiple dilutions in lieu of replicate injections (due to extremely high instrument precision). Replicate injections should be used for periodic validation of instrument precision.

 

[readalot]

Excellent summary.

If anyone wants full paper for Table 2 above:

Link (click "download full pdf" box)

Replicate injections should be used for periodic validation of instrument precision.

Absolutely.

Based on this data, it appears it would be of more value to prioritize single injections of multiple dilutions in lieu of replicate injections (due to extremely high instrument precision).

Yes this would give you what I term "method precision" and gives you RSD that includes operator/method imprecision plus the instrument.

The effort you are putting in here will serve you well and take you far.

 

[readalot]

Instrument precision (right column), RSD:
First 2 injections: 0.077%
First 3 injection: 0.194%
First 6 injections: 0.251%
All 7 injections: 0.262%

And one more comment just for clarity...while the RSD may be increasing, what is happening to the confidence interval as N increases? Remember the CI scales as the t-score ÷ sqrt(N).

Very nice data set @Chromate.

An example on an actual AAS adulterant test with the method precision approach above plus a spike recovery will really demonstrate to folks you've got the accuracy and precision locked down.

Best wishes.

PS: don't worry @phenominal34 I'm still just actively doing my hidden troll act on here. I haven't fooled anyone. Just busy trolling @Chromate with clown-based nonsense.

Regards,
hidden troll / clown

 

[Mr.Olympia24]

Hello MESO,

We are an analytical lab based in the USA and specialized in the analysis of health supplements, research peptides, and research chemicals.

For orders and inquiries, email: hello@chromate.org

For up-to-date pricing information, visit: chromate.org/meso

On that page you will also find guidelines for sample preparation and popular shipping options for our American customers.

Late in 2023 we performed a soft launch on this forum. Since then we have acquired new instruments, calibrated our equipment, and greatly expanded our services.

We look forward to serving you!


Chromate Team

Hello MESO,

We are an analytical lab based in the USA and specialized in the analysis of health supplements, research peptides, and research chemicals.

For orders and inquiries, email: hello@chromate.org

For up-to-date pricing information, visit: chromate.org/meso

On that page you will also find guidelines for sample preparation and popular shipping options for our American customers.

Late in 2023 we performed a soft launch on this forum. Since then we have acquired new instruments, calibrated our equipment, and greatly expanded our services.

We look forward to serving you!


Chromate Team

Hello!

I would like to know if you could provide me with an example of what these reports would look like. Also, I would be interested to know if you have plans to implement a page to authenticate them in the future.

 

[nightprowler7]

Looks like my sample went MIA. I'll send another through a different courier and update when results are received.

Any updates

 

[readalot]

T

Hello!

I would like to know if you could provide me with an example of what these reports would look like. Also, I would be interested to know if you have plans to implement a page to authenticate them in the future.

Two examples in this thread.

 

[Chromate]

Hello!

I would like to know if you could provide me with an example of what these reports would look like. Also, I would be interested to know if you have plans to implement a page to authenticate them in the future.

Hello,

The requested feature has already been implemented.

Give it a try to view an example report.

Chromate Client Portal

Job number: 10101
Access code: QWERTY123456

 

[UncleBuns]

Any updates

First sample definitely lost in the mail. Second sample is on the way through a different courier. I'll update when I get the report.