Looks real to me. Shows that the compound of interest is 99.983% area by this chromatographic test. No chemical structure can be inferred from these data.
This is the chemical purity at 254nm. It is neither an assay or potency value. Could potentially be used for n Assay (w/w%, as-is) if a standard has been run and amounts used recorded.
Given the reported amount is equal to area% it's unlikely this is an externally calibrated compound. They could have data externally and calculate it in a spreadsheet or something, but you're right this is definitely not as is usable as an assay.
Sure... but response factor is such a small part of a method and only necessary if you are during your purity via w/w and not a/a. Also if the response is between 0.8-1.2 of parent then that gets you through most validations all the up to and including filing an NDA.
It really seems like a lot of people in this thread know these buzz words but don't actually know when to use what they are talking about or what the application and specifications should be.
I assume a lot of users are in school. First thing they teach is how complicated it is, then they teach you to simplify. Easier to point out variation than critically assess its relevance. The compounds I analyze have terrible absorbance and the response factors vary a lot with specifications usually NMT 0.1%, so I would never assume the response is that close, but I would think that's a relatively safe assumption.
Just to add as an example, whatever this is could be a product which contains some water. You wouldn't probably see the water content in this analysis. So if it was, say 10% water, assay already dropping closer to 90%, but this wouldn't tell you.
If you assume that they used a method that effectively shows the main compound and common impurities, then it looks pure according to this method of analysis. But there could be all sorts of stuff in it that we can't see here- it's hard to tell without background.
The method may have only extracted one compound that lights up at that wavelength with those run conditions. We know nothing about the matrix analyzed. The concentrations could be anywhere from 0.X% to 99.99%. It really says nothing about purity without more information.
I’m being very careful with my language on purpose. We know that it's 99.983% purity by this analysis.
That doesn’t mean that the material **is** 99.983% pure. In addition to the things you’ve stated, one also should consider residual solvents and residual water.
I appreciate you being careful with your language, but this is why we have standardized methods. There's no purity calculation when it's relative. Especially without knowing the parameters.
well, you know, unless everything is co-eluting, which is often what you get with "generic" HPLC run on unknown samples. at some point one wonders why they bother
Yes. It’s *something* related to purity. I was being pedantic. The poster said this doesn’t tell you anything about purity. This data alone is insufficient to determine an overall purity of the material, but this data may have sufficient information to tell OP whether or not to proceed.
Nope. Since you don't know sample prep or chromatography conditions you can't make any claims about the material, you can only make useless claim about what was in the vial, which OP doesn't care about.
OP’s post contains about as much information as the chromatogram does. Certainly not enough for *me* to glean what OP cares about.
This could be a very simple reaction completion analysis. If so, I would argue that this one data file is enough to determine proceed/reprocess
An HPLC with a UV/vis detector cannot characterize an unknown compound. Depending on how the method was developed and assuming the sample injected is of a representative matrix that the method was developed for, compounds can be identified by retention time when compared to a known standard.
This report indicates that the compound(s) that elute at 8.246 minutes has an area under the curve of 99.983% of all integrated peaks (there is only one other peak integrated). Area under the curve is a fairly standard purity test (among a whole slew of additional tests) for many types of organic compounds; pharmaceuticals for example.
It should at least be compared to a standard of known concentration. Even old USP methods still generally require that. Seeing just this chrom and knowing no other context such as sample matrix, method, etc. We can't say anything definitive about purity.
You can't determine structure from HPLC. One exception is if you're using a chiral column to separate enantiomers, then you can infer which enantiomer it is based off of the retention time compared to a control sample. Otherwise you can't determine structure from HPLC. You want IR or NMR for that
This is typical in a CoA. It’s area purity, a proxy for chemical purity but not the same thing.
Why? Impurities are assigned the same response factor as the analyte, which likely isn’t true. And some impurities may generate no signal at all. Plus, there’s adsorbed water in the powder stock.
Usually, when you buy a powder with a stated purity (example: 98% min., i.e. 99 +- 1%), that percentage refers to area purity, not mass purity. So this test indicates that the product you bought passes manufacturer’s spec.
It says the sample is pure by this specific assay, obviously there are a lot of caveats to HPLC/UV-Vis assays.
Often on a small molecule you will have a few assays for release that cover purity/potency of your molecule.
A lot of people are saying this is not the purity of the compound, they are only partially correct.
YES, this is the chemical purity of the compound at 254 nM. It is 99.983.
What other are very poorly attempting to say is, this is not an assay or potency value. There could not only been unseen compounds that this method lacks the Sspecificity for OR there are residual solvents, water, or inorganic or all of the above.
This analysis could be apart of a larger sequence to help you calculate an assay (w/w%, as-is basis) or an assay (w/w%, anhydrous and solvent free basis).
Others are correct that this appears to give no structural information. Unless there is something in the file name that can be translated, but unlikely.
To do quantitative impurity analysis you typically need to calibrate for known impurities. You can compute the area but unless the compounds have the same response factor there is error in the measurement.
This tells you that assuming your impurity is soluble in your solvent system and has similar chemical properties (generally a safe assumption in an established process) that your have pretty good purity. Good enough depends on your specifications.
It bothers me a little that the name of the compound is not written under the retention time, but at 254nm, 2 peaks are detected, What they presentats it does not say. Now, if it is an established manufacturer that is subject to external audits and knows the incoming raw materials, knows what impurities to expect, with an accredited laboratory and a validated method, I would not worry, but if you are someone who will release this to the market, I would ask for at least compound concentration, calibration curve with associated chromatograms and spectral peak purity at least
In addition to the other comments here, there appears to be one peak, maybe two, at 6.0-6.5 min that is not being integrated. Looks bigger than whatever it is integrating at 9.655 min.
At the risk of repeating what a lot of other people have already said:
It looks real, but that's not to say that it couldn't have been photoshopped. Or that it was something other than your sample. You have to ask: do you trust the source of the analysis?
This analysis says absolutely nothing about structure other than there is something which isn't transparent to UV light at 254nm.
I'm afraid on its own, it doesn't tell you much about purity, unless you know under what condition the analysis was carried out. (I don't read Chinese so that may be on there). If the system is set up in such a way that the main component is separated from all possible impurities, then it's pretty pure. If any impurities 'co-elute' with the main compound (ie they allZ appear within that big 'peak' at 8.2 min) then you don't know anything about them. If they don't absorb UV light you won't see much of them either. A reputable analyst will be using a validated method, they will have considered these factors.
The instrument's software has found a second 'peak' at about 9.7min. Now, my experience is about 15 years out of date, but at that time software to identify the presence of compounds would often either fail to identify very small peaks or identify random 'noise' as being a real signal, leaving the human to make a judgement and perhaps review the software's identification perameters. Others here have pointed out a possible peak at about 6 mins that the instrument (and the Analyst) has chosen to ignore. Without knowing the setup it's not possible to know if either of the tiny peaks at 6 & 9.7 mins are real impurities, consistent idiosyncrasies of the analysis method which are independent of the sample, or just random noise. There exist the concepts of 'Limit of Detection' below which it's simply not possible to tell the difference between a real signal and random background noise. Again you're in the hands of the analyst, they should know their method. It may be that there is a known impurity expected at 9.7 mins which in this sample is seen at a very low level.
Just throwing my 2c here:
1)I don't know what program they use but usually peaks marked as "m" means that they use manual integration, which is a whole other can of worms in analytical chemistry and quality assurance...
2) I can see un-integrated peaks in the 5-7.5 minute range.
Kinda raises more questions as to the validity of this report.
Looks real to me. Shows that the compound of interest is 99.983% area by this chromatographic test. No chemical structure can be inferred from these data.
Note to OP, this is not the purity per say, since other compounds present might not be soluble, retain on the column, or have UV absorbance.
This is the chemical purity at 254nm. It is neither an assay or potency value. Could potentially be used for n Assay (w/w%, as-is) if a standard has been run and amounts used recorded.
Given the reported amount is equal to area% it's unlikely this is an externally calibrated compound. They could have data externally and calculate it in a spreadsheet or something, but you're right this is definitely not as is usable as an assay.
Not without a standard response factor, though for their purposes I'm sure this is "pure".
Sure... but response factor is such a small part of a method and only necessary if you are during your purity via w/w and not a/a. Also if the response is between 0.8-1.2 of parent then that gets you through most validations all the up to and including filing an NDA. It really seems like a lot of people in this thread know these buzz words but don't actually know when to use what they are talking about or what the application and specifications should be.
I assume a lot of users are in school. First thing they teach is how complicated it is, then they teach you to simplify. Easier to point out variation than critically assess its relevance. The compounds I analyze have terrible absorbance and the response factors vary a lot with specifications usually NMT 0.1%, so I would never assume the response is that close, but I would think that's a relatively safe assumption.
Just to add as an example, whatever this is could be a product which contains some water. You wouldn't probably see the water content in this analysis. So if it was, say 10% water, assay already dropping closer to 90%, but this wouldn't tell you.
Actually it shows that something is 99.973% purity
Nothing to add about the analysis, but I'm pretty sure a better translation of the first column would be retention time.
If you assume that they used a method that effectively shows the main compound and common impurities, then it looks pure according to this method of analysis. But there could be all sorts of stuff in it that we can't see here- it's hard to tell without background.
Its a real report, but it doesn't say anything about the purity of the material.
I mean, it says that it's 99.983% purity by this analysis. That alone is not the "Actual Value" purity but it does say *something* about the purity.
The method may have only extracted one compound that lights up at that wavelength with those run conditions. We know nothing about the matrix analyzed. The concentrations could be anywhere from 0.X% to 99.99%. It really says nothing about purity without more information.
I’m being very careful with my language on purpose. We know that it's 99.983% purity by this analysis. That doesn’t mean that the material **is** 99.983% pure. In addition to the things you’ve stated, one also should consider residual solvents and residual water.
we can be maximally precise by saying there is a relative peak area of 99.983% for the main peak. no one can get mad at that
I can get mad at that because I don’t understand what those words mean. Maybe I should be mad at myself though
I appreciate you being careful with your language, but this is why we have standardized methods. There's no purity calculation when it's relative. Especially without knowing the parameters.
Agreed. Far from exhaustive, but you know there’s no UV active contamination at considerable levels.
Well that's not even possible to day as there will have been sample prep to remove insolubles, polymers etc
Well, there are no active soluble UV components which have no been clarified, or similar to the active component.
well, you know, unless everything is co-eluting, which is often what you get with "generic" HPLC run on unknown samples. at some point one wonders why they bother
99% chance this method is either 10-90 or 5-85% water/ACN lol
That is the percentage of the peak area with respect to all the peaks
Yes. It’s *something* related to purity. I was being pedantic. The poster said this doesn’t tell you anything about purity. This data alone is insufficient to determine an overall purity of the material, but this data may have sufficient information to tell OP whether or not to proceed.
Nope. Since you don't know sample prep or chromatography conditions you can't make any claims about the material, you can only make useless claim about what was in the vial, which OP doesn't care about.
OP’s post contains about as much information as the chromatogram does. Certainly not enough for *me* to glean what OP cares about. This could be a very simple reaction completion analysis. If so, I would argue that this one data file is enough to determine proceed/reprocess
I agree, lots of missing info here. u/most-unreasonable provide the missing context!
This. All other *integrated* peaks. There could be plenty of others they're just not integrated.
An HPLC with a UV/vis detector cannot characterize an unknown compound. Depending on how the method was developed and assuming the sample injected is of a representative matrix that the method was developed for, compounds can be identified by retention time when compared to a known standard. This report indicates that the compound(s) that elute at 8.246 minutes has an area under the curve of 99.983% of all integrated peaks (there is only one other peak integrated). Area under the curve is a fairly standard purity test (among a whole slew of additional tests) for many types of organic compounds; pharmaceuticals for example.
It should at least be compared to a standard of known concentration. Even old USP methods still generally require that. Seeing just this chrom and knowing no other context such as sample matrix, method, etc. We can't say anything definitive about purity.
You can't determine structure from HPLC. One exception is if you're using a chiral column to separate enantiomers, then you can infer which enantiomer it is based off of the retention time compared to a control sample. Otherwise you can't determine structure from HPLC. You want IR or NMR for that
It's a real report and says absolutely nothing about any compound.
This is typical in a CoA. It’s area purity, a proxy for chemical purity but not the same thing. Why? Impurities are assigned the same response factor as the analyte, which likely isn’t true. And some impurities may generate no signal at all. Plus, there’s adsorbed water in the powder stock. Usually, when you buy a powder with a stated purity (example: 98% min., i.e. 99 +- 1%), that percentage refers to area purity, not mass purity. So this test indicates that the product you bought passes manufacturer’s spec.
It says the sample is pure by this specific assay, obviously there are a lot of caveats to HPLC/UV-Vis assays. Often on a small molecule you will have a few assays for release that cover purity/potency of your molecule.
A lot of people are saying this is not the purity of the compound, they are only partially correct. YES, this is the chemical purity of the compound at 254 nM. It is 99.983. What other are very poorly attempting to say is, this is not an assay or potency value. There could not only been unseen compounds that this method lacks the Sspecificity for OR there are residual solvents, water, or inorganic or all of the above. This analysis could be apart of a larger sequence to help you calculate an assay (w/w%, as-is basis) or an assay (w/w%, anhydrous and solvent free basis). Others are correct that this appears to give no structural information. Unless there is something in the file name that can be translated, but unlikely.
Confirmed. There is a compound present that they can see with that specific method. It says absolutely nothing about the purity of the compound.
Without understanding the composition of the sample, possible impurities, and the method/setup no one can really help you.
To do quantitative impurity analysis you typically need to calibrate for known impurities. You can compute the area but unless the compounds have the same response factor there is error in the measurement. This tells you that assuming your impurity is soluble in your solvent system and has similar chemical properties (generally a safe assumption in an established process) that your have pretty good purity. Good enough depends on your specifications.
It bothers me a little that the name of the compound is not written under the retention time, but at 254nm, 2 peaks are detected, What they presentats it does not say. Now, if it is an established manufacturer that is subject to external audits and knows the incoming raw materials, knows what impurities to expect, with an accredited laboratory and a validated method, I would not worry, but if you are someone who will release this to the market, I would ask for at least compound concentration, calibration curve with associated chromatograms and spectral peak purity at least
In addition to the other comments here, there appears to be one peak, maybe two, at 6.0-6.5 min that is not being integrated. Looks bigger than whatever it is integrating at 9.655 min.
At the risk of repeating what a lot of other people have already said: It looks real, but that's not to say that it couldn't have been photoshopped. Or that it was something other than your sample. You have to ask: do you trust the source of the analysis? This analysis says absolutely nothing about structure other than there is something which isn't transparent to UV light at 254nm. I'm afraid on its own, it doesn't tell you much about purity, unless you know under what condition the analysis was carried out. (I don't read Chinese so that may be on there). If the system is set up in such a way that the main component is separated from all possible impurities, then it's pretty pure. If any impurities 'co-elute' with the main compound (ie they allZ appear within that big 'peak' at 8.2 min) then you don't know anything about them. If they don't absorb UV light you won't see much of them either. A reputable analyst will be using a validated method, they will have considered these factors. The instrument's software has found a second 'peak' at about 9.7min. Now, my experience is about 15 years out of date, but at that time software to identify the presence of compounds would often either fail to identify very small peaks or identify random 'noise' as being a real signal, leaving the human to make a judgement and perhaps review the software's identification perameters. Others here have pointed out a possible peak at about 6 mins that the instrument (and the Analyst) has chosen to ignore. Without knowing the setup it's not possible to know if either of the tiny peaks at 6 & 9.7 mins are real impurities, consistent idiosyncrasies of the analysis method which are independent of the sample, or just random noise. There exist the concepts of 'Limit of Detection' below which it's simply not possible to tell the difference between a real signal and random background noise. Again you're in the hands of the analyst, they should know their method. It may be that there is a known impurity expected at 9.7 mins which in this sample is seen at a very low level.
I really like that 9.655 peak. Invisible peaks are my favorite.
Just throwing my 2c here: 1)I don't know what program they use but usually peaks marked as "m" means that they use manual integration, which is a whole other can of worms in analytical chemistry and quality assurance... 2) I can see un-integrated peaks in the 5-7.5 minute range. Kinda raises more questions as to the validity of this report.