FT-IR KBr

Off-topic conversations and chit-chat.

22 posts Page 1 of 2
Hi all

In IR you have make the KBr pellet for solids (crystalline) products. What do you think of weighing the sample in an analytical balance (1 or 2 mg!!) and and the 300 mg of KBr. And recoding the weights for GLP purposes.

Fernando
I've never seen a document that's asked to do this. If you're running the IR test for qualitative purposes (identification against reference standard or elucidation of structure) then it's strictly a qualitative test. If you were doing some sort of quantitative analysis, then I'd understand.

Side note: if you get the chance to upgrade your IR, I recommend picking up an ATR. It makes the KBr pellet unnecessary.
If you start with 300.0mg of KBr and make a pellet, what is the variability of the weight of the pellet when you are done? I could see it easily being + or - 1 mg.
Hi All

I'm sorry if I was not clear with this issue, I work in R&D and some colleages in QC are insisting in recording the weight (about 1 or 2 mg!!!!!!!). I asked them where is the regulation or in what pharmacopeia, ICH or FDA regulation are basing this procedure, no answer. I think they are exaggerating, this is a qualytative test and if if you wanted to do it quantitative you have to weight about 30 mg of sample and 900 mg (!!!!!!!!) of KBr IR quality.

Best regards.

Fernando
How hard *is* it to record the weight? This may be one of those things that's not worth fighting over.
-- Tom Jupille
LC Resources / Separation Science Associates
tjupille@lcresources.com
+ 1 (925) 297-5374
Fernando,

I am in agreement with you and I have spent my entire career in GMP facilities. There is no regulation to document weights of sample or KBr for a qualitative test. It's not something I've ever seen come up during an audit.

Tom has a point - it's not hard to record the weight but I have seen something simple like this get out of control. First they start recording the weight and then the SOP gets revised such that a weight range is assigned based on weighing history and before you know it there is a deviation because the procedure said to weigh 300 +/- 5 mg of KBR and someone weighed 306 mg of KBr.

This is what makes the ATR even more attractive. You just scoop some sample onto the crystal, tighten the arm and take your reading. So simple.
Hi all members

Thank you Tom and Blazer

I agree with you, I was very surprised that the weights that they want to record (1 or 2 mg!!!!!) where so far beyond the minimun wheight of the analitycal balance that I was complelled to make the post.

Again thank you

Fernando
When I see things like that, I'm glad I'm retiring next year.

If it doesn't add any value, don't do it is my motto.

Recording a 2mg weight lends spurious rigour and adds nothing to the scientific value of the IR measurement.

I've seen some reasonable suggestions - like comply, what have you got to lose?

This attitude is defeatist and will just encourage mindlessness.

I say, fight to the bitter end - we can defeat them, every battle should be fought as if the trivial nonsense they shove down our throats mattered, enormously!

Best Regards

John
johntee061 wrote:
Recording a 2mg weight lends spurious rigour and adds nothing to the scientific value of the IR measurement.


Best Regards

John
Izaak Kolthoff: “Theory guides, experiment decides.”
Hi johntee061

I agree 100 % with you but sadly for me I'm retiring in FIVE years and this type of nonsense is increasing. The regulations are OK and is good science to comply with them but this mindlessness as you rightly put is very common.

Best regards

Fernando
Fernando wrote:
this type of nonsense is increasing...



This seems to be EVERYWHERE. I do R&D support and troubleshooting for manufacturing. Oftentimes, time is critical for getting manufacturing issues solved. In the past, I could order online with company credit card, get chemical or supply next day.

Now company has forbidden "next day" unless a vice-president OKs.

We're also switching to different purchasing system: I have to get quotes (up to 48 hours), then purchase through such quote even if higher cost than ordering directly, then after the "button" is pushed, I must E-mail someone and get the charge to be routed to the right account, as the software doesn't let us do this in advance. Then when chemical arrives on-site, a chemical coordinator must sign this in, issue barcode, put on safety labels, etc. Maybe corporate feels this system will work for repeated purchased items, but it doesn't fit for R&D. But procurement reduced their headcount. So the order process for me goes from less than five minutes to at least an hour all told for each order, maybe double that as I learn the system. Apparently this is "progress".

This is akin to instead of walking out to mailbox to get the mail: walking outside, driving to the airport, getting a rental car, driving home, getting rental picked up, taking Uber back to airport, picking up own car, driving home, and stopping at mailbox to pick up the mail.
See also this Restek article by Koni Grob

http://www.chromtech.net.au/pdf2/Restek ... E_1-44.pdf

After despairing at the way that overzealous and inappropriate application of GLP in a research lab stifled innovation I asked whether the following method for making a fruit salad (by my son then aged 6) would be an acceptable SOP :D

Image

I just love the "we did sum uthur things"

Cheers

Ralph
Regards

Ralph
GOM wrote:
See also this Restek article by Koni Grob

http://www.chromtech.net.au/pdf2/Restek ... E_1-44.pdf

After despairing at the way that overzealous and inappropriate application of GLP in a research lab stifled innovation I asked whether the following method for making a fruit salad (by my son then aged 6) would be an acceptable SOP :D

Image

I just love the "we did sum uthur things"

Cheers

Ralph


The little guy didn't even sign and date the SOP for fruit salad! The taste of the salad may be severely compromised by these procedural anomalies. I would raise a CAPA and advise extra training.
Writing the perfect SOP.
Firstly, I would recommend an antiquated word processing package that is virtually impossible to use. Why use something like Word, that would be far too easy?
Always employ a numbering system that you do not fully understand. After all, no one does, so it doesn’t really matter. This has the beauty of making the numbering process 10 times longer than writing the document text.
Write the procedure, innocently, as you carry it out with all the required measures and checks.
Send it for review. It is essential that the reviewer is as hair-brained as possible and has never carried out a laboratory procedure.
It is at this vital stage that spurious rigour is added.
Essentials, such as the shelf where the column is stored when not in use or the name of the person’s dog who calibrates the ruler you use when measuring GC column ends can be recorded. Several logs should be specified.
It is also vital to specify parameters you have no control over, at this time. Throw away knowledge will not deter the hair-brained. Remember, they might know far less than you but they are far more persistent than you ever could be.
It is best to surrender early, rather than late. Willingly, specify that you will change the injection syringe after every 132 injections and not just when you need to. Too much thought should not be given to specifying the random, after all you are specifying the random.
You will be asked “how do you know?” - a lot. For example, you will be asked if the hexane you are using is really hexane. How do you know? Don’t even bother suggesting that if all the components you used were not what they were supposed to be, it simply wouldn’t work. This kind of holistic, knowledge-based approach is clearly subversive and undermines the very existence of your clipboard wielding hair-brain. It is best to capitulate, get a clipboard of your own and head off to ‘audit’ the multi-billion dollar, market leading chemical suppliers. They will look a bit surprised when you ask them how they know it’s hexane - they did with me, anyway.
This review stage will be protracted: months, maybe. At the end of it all you will have a perfectly unworkable set of nonsense that you couldn’t possibly follow.
I find traditional SOPs to be very confusing and clumsy, especially with the indentations so many use. It seems that many copy a poor system.
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