(Hive Addict)
09-18-03 18:01
No 459834
(Rated as: excellent)
Quantitative and Qualitative TLC Analysis of 5meo DMT
By ClearLight and Desert Sun
We are reporting here our method for qualitative and quantitative analysis of the titled compounds using prior hive posts in addition to a unique photometric method for quantitative analysis of UV and visualized chromaphores.
Using TLC plates we have determined the rF values of the titled compounds and identified their wet and dry chromaphores using the modified Van Urk/Salkowski reagent system as well as their respective concentrations.
(see link for full pdf document)
http://www.angelfire.com/blog/clearlight
Conclusions:
Qualitative measurements of TLC plates are now possible using simple, home equipment. Utilizing a free program, Image, background subtracted image density (BSID) measurements, when averaged, correlate very well with the loadings on the plate. Use of a wet plate will not provide accurate measurements but will provide some qualitative information as to the nature of the materials under analysis. A 5 microliter spot containing 25 micrograms of the title compound was compared to a 10 microliter spot containing 50 micrograms of the title compound. The results for both U.V and visualized BSID measurements were 1.99 and 2.09 respectively.
Short Wave UV measurements of the image as well as dry visualized measurements provide accurate information as to the total amount of compound present when compared to a standard. This method now provides the experimenter with a rapid, easy way to quantify the amounts of compounds present in a sample and may be correlated to other compounds of interest to provide rapid, accurate measurements of your materials. This system compares favorably to analysis done using $20k –30k systems.
Infinite Radiant Light - THKRA
(Hive Addict)
09-21-03 17:35
No 460298
I'll be doing the translated into "easy" version of this soon... What this article really does is let you tell you how much of your pill is the goodies and how much is gaak, or the reaction your doing as well..
Since DEA prohibits drug testing labs from telling you how much is there, now you can do it yourself.
Infinite Radiant Light - THKRA
(Moderator)
09-22-03 01:31
No 460364
Some short questions and remarks:
- For a quantitative measurement you need a calibration curve with several different concentrations.
- Use high dilutions for TLC, the samples look heavily overloaded.
- That also helps in a uniformly staining of the spots, a prerequisite for quantitative measurements. The dark ring looks like a staining artifact due to overloading and/or incomplete staining. The best way to stain small sheets is by dipping them into the solution.
- Why do you add the FeCl3 to the spray reagent?
(Hive Addict)
09-22-03 03:52
No 460369
re: Calibration curve.. Didn't know that applied to tlc thought only to cuvette based spectrophotometry. So are you saying that the loadings will be non-linear and hence we need multiple measurements to fit the curve?
The dilutions were 25mg in 5 ml MeOH = 25 micrograms. Your right.. I should have used nanograms. ~ 100 should be about right..
-Dipping has not been successful in the past. The spots run and spread out..
- Re: FeCl3 This + H2S04 is the salkowski reagent, which makes this system more rapid( 3-5 min) vs 3-8 hours for the Van Urk reagent. These are from the prior paper I posted on the indole tlc visualization reagent. The combo works nicely.
I'll try it again w/ a more diluted sample.. see what happens..
Infinite Radiant Light - THKRA
(Moderator)
09-22-03 05:26
No 460374
The color using Van-Urk (= Ehrlich) reagent develops instantly while heating with an hair-blower. For simple and fast experiments this should do it without FeCl (at least if you have the "calibration curve" on the same sheet and take care of a uniform heating). Washing out the spots while dipping depends on several factors: Overloaded spots tend to wash out more easily and the more polar the staining solution is the more washing out you'll see. So use less conc. HCl to minimize H2O content or use more solvent, maybe substitute methanol with a more hydrophobic solvent like ethanol or isopropanol.
(Hive Addict)
09-22-03 16:00
No 460460
So do you think that the pdf ref. in post Post 332278 (ClearLight: "The Van Urk-Salkowski Reagent - Indole Specific", Methods Discourse) is irrelevant? I"m curious as to your opinion on that work...
thx!
Infinite Radiant Light - THKRA
(Moderator)
09-23-03 07:12
No 460551
No, it's not irrelevant, but is has to be tweaked to get reliable results. The software to analyze scientific images is a great find (Image Tool, http://ddsdx.uthscsa.edu/dig/itdesc.html