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- Posts: 3
- Joined: Sat Apr 25, 2020 9:17 am
I have the same problem and like to hear how I can solve this.
Discussions about GC-MS, LC-MS, LC-FTIR, and other "coupled" analytical techniques.
Consumer Products Guy wrote:ucanmoruk wrote:Consumer Products Guy wrote:
Our hand sanitizer products were over 60% ethanol, but in our validation studies boss made us go down to extremely low levels, even those would be so many orders of magnitude less than our target levels. He was "afraid" of ever having to answer a question should an auditor ask.
chemist23 wrote:Consumer Products Guy wrote:
I am having difficulty extracting all of the alcohol from hand sanitizer products in the form of a 'gel'. While it appears the gel fully dissolved in water, the results of my alcohol content say otherwise. Did you always use water as your solvent and have you ever tested a gel matrix? If so what solvent did you use?
Consumer Products Guy wrote:chemist23 wrote:Consumer Products Guy wrote:
I am having difficulty extracting all of the alcohol from hand sanitizer products in the form of a 'gel'. While it appears the gel fully dissolved in water, the results of my alcohol content say otherwise. Did you always use water as your solvent and have you ever tested a gel matrix? If so what solvent did you use?
Our alcohol-containing products were hand sanitizer gels; we always used water as the solvent, and had no issues with our assay. We also cGMP-validated the USP procedure, adapted for our gel finished product, our pointy-haired boss demanded that.
Production QC also had no issues with the procedure.
There were some potentially proprietary sample preparation innovations we developed to aid in the analysis of a volatile analyte accurately. One involved weighing 3 gram sample into a volumetric flask already containing about 50 ml water.
chemist23 wrote:Consumer Products Guy wrote:chemist23 wrote:
I am having difficulty extracting all of the alcohol from hand sanitizer products in the form of a 'gel'. While it appears the gel fully dissolved in water, the results of my alcohol content say otherwise. Did you always use water as your solvent and have you ever tested a gel matrix? If so what solvent did you use?
Our alcohol-containing products were hand sanitizer gels; we always used water as the solvent, and had no issues with our assay. We also cGMP-validated the USP procedure, adapted for our gel finished product, our pointy-haired boss demanded that.
Production QC also had no issues with the procedure.
There were some potentially proprietary sample preparation innovations we developed to aid in the analysis of a volatile analyte accurately. One involved weighing 3 gram sample into a volumetric flask already containing about 50 ml water.
Measuring by weight would be easier than trying to pipette a specific volume. But then how would you get your result in v/v%? the only way I assume would be to know the density of the gel.
chemist23 wrote:
Measuring by weight would be easier than trying to pipette a specific volume. But then how would you get your result in v/v%? the only way I assume would be to know the density of the gel.
CallumShortland wrote:
please describe the results
Maja Djekic wrote:
Hello everyone,
this topic is interesting to me because I want to confirm that "alcohol-free" cosmetic cream is really free from alcohol. I planed to analyze it on GC-FID but I am not sure how to prepare the sample so I can extract alcohol (if there is any) because the cream matrix is oily? Any experiences or ideas?
Thank you in advance.
LALman wrote:
I'll just add that using a DB-VRX column to do alcohols is possible but I would worry about the hand cream composition. You don't want semivolatiles in the handcream getting on a column that has a max temp of 260C.
MSCHemist wrote:
I thought methanol was impossible to do via GC/MS you need an FID. The molecular weight of methanol is 32amu which is also the molecular weight of O2.
I do ethanol via headspace GC/ms. I use acetonitrile as the internal standard and use full evaporative. I put 10ul into a 10ml vial and heat to 120degC for 10 minutes. If I am doing an oil soluble sample I use acetone instead of water. I use a 0.5df wax coln though I am told 1701 or 624 works better.
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