(Hive Bee)
06-04-03 15:26
No 437765
      Some helpful TLC detection reagents
(Rated as: excellent)

General: Anisaldehyde-Sulphuric acid
Dipping sol, 1 ml of anisaldehyde 2 ml conic H2SO4 in 100 ml of GAA or sprayed with 8 ml conic H2SO4 and 0.5 ml of anisaldehyde in 85ml of MeOH and 10 ml of GAA. Good for essential oil separation, phenols and terpenes. (Lots of pretty colours for all our favourite compounds.)

General: Phosphomolybdic Acid Spary
5% sol of phosphomolybdic acid in ethanol followed by a brief (5-20 min) heating at 110C gives blue-gray spots against a yellow background. Good for many organic compounds including substituted phenols indole derivatives and essential oil components.

For Alcohols: Spray
6% ceric ammonium sulphate in 2N HNO3 will yield brown spots on yellow background.

For aldehydes and ketones: spary
Dissolve 0.4g 2,4-dinitrophenylhyrazine in 100 ml 2N HCl will yield yellow to red spots on pale orange background.

For Alkaloids: (Reagent: Iodoplatinate) Spray
(a) 5% platinic chloride in H2O (b) 10% aqueous KI Color reagent: mix 5 ml of (a) with 45 ml of (b), dilute to 100 ml with H2O will yield basic drugs yield blue or blue violet spots that turn brown yellow; addition of conc. HCl, 1 part to 10 parts of spray solution, will often increase sensitivity of reagent.

For Amines and amino acids: (reagent Indanetrione hydrate [ninhydrin]) Spray
Mix 95 parts 0.2% ninhydrin in n-butanol with 5 parts 10% acetic acid. This will yield Yellow, pink-red, or violet spots on white background.

For Barbiturates: (Reagent: s-Diphenylcarbazone Bromocresol green) Spray
0.1% reagent in 95% ethanol. Dissolve 0.04g BCG in 100 ml of ethanol; add 0.1N NaOH until blue color just appears. Will yield Purple spots. Acids: yellow spots on blue background; bases: blue spots on green background.

For Inorganic ions: (test for Hg) (Reagent: Ammonium sulfide) Spray
Saturated aqueous H2S made alkaline with NH3 Cations detected black: Ag, Hg, Co, Ni; brown: Au, Pd, Pt, Pb, Bi, Cu, V, Ti; yellow: Cd, As, Sn; yellow-orange: Sb

Thin-Layer chromatography 4th Ed Chromatographic science series vol 81
(Hive Addict)
06-04-03 19:28
No 437793
      Sensitivities?  Bookmark   

Could you post the lower limit of detection sensitivites for these visualization reagants?   ng range?? mg range?


Infinite Radiant Light - THKRA
(Hive Bee)
06-04-03 20:32
No 437805
      for the FSE  Bookmark   

TLC of salvinorin A (I thought I would try to slip this on into this thread...)

Post 437802 (ChemisTris: "Quantification of Salvinorin A from S. divinorum", General Discourse)
Idetification and Quantification of Salvinorin A
"Typical TLC analyses carried out during the extraction of S. divinorum samples and purification by column chromatograpgy used 20 cm x 20 cm silica gel G-F245 plates. Plates were developed with a mixture of hexane:EtOAc 1:1 and salvinorin spots visualized using either the vanillin-sulfuric acid or anisaldehyde sulfuric acid spray reagent, followed by heating in an oven at 100 C for 10 minutes."
"Authentic salvinorin A...appeared as a violet-blue spot with an Rf of 0.45 - 0.53"

Got democracy?
(Hive Bee)
06-06-03 01:53
No 438096
      ClearLight: No ranges were given, I would...  Bookmark   

ClearLight: No ranges were given, I would guess that most of these guys/gals would be using Carmag TLC gear. I think the smallest applicator tubes for that stuff is .5 ul. So a guesstimate at .5 to 5ul and maybe diluted to a third of that vol?
(Hive Adickt)
06-06-03 10:34
No 438191
      ClearLight ng range. a good TLC beat's a ...  Bookmark   

ClearLight ng range. a good TLC beat's a standard GCMS/HPLCMS.