Products

  The Dynamic TLC Program

Dynamic Adsorbents Inc.'s technology and experience has resulted in one of the broadest TLC-HPTLC-"S" HPTLC programs in the world. Our TLC-HPTLC program is one of the most complete. Included in the program are silica gels, aluminas, cellulose and PEI cellulose. In addition, we supply these materials in a broad variety of layers and plate types.
 

Layer Code/Type	Layer Description	Feature/Benefits
Analytical TLC
HLO	Hard-Layer: Organic Binder HLO the most abrasion resistant high resolution TLC product available in our program. Write directly on the plate. Outstanding detectability, sensitivity; Minimal breakage.	High resolution Standard of the industry Durable reflective surface
Alumina A, B, N	Select the pH most appropriate to your separation, A=Acid, B=Basic, N=Neutral. Alumina is stable a pH 4 - 14 and can be used to separate most compounds, especially basic.	Ideal for the separation of basic compounds Standardized Particle for TLC, prep TLC Stable reproducible layer
PEI - Cellulose	Ideal Anion ion-exchanger for many life science applications e.g. nucleic acid compositions. Keep refrigerated at 4º Celcius to avoid discolorization.	Long chain anion exchanger Bio-life science applications Stable reproducible layer
Cellulose	Available as microcrystalline, Avicel, and Native (MN layers for the separation of polar compounds via liquid - liquid partition chromatography.	Liquid - liquid partition separation mechanism Ideal for polar analytes Available as crystalline or native fibers
HPTLC and "S" - HPTLC Advanced Layers
HPTLC	A 5 micron particle, 200 micron thick layer, suitable for very difficult separations. Spots of 1-2 mm will optimize separations. Three to five times the resolving power of TLC. Fast development time.	Obtain 3-5,000 theoretical plates /5 cm Ideal for the most difficult separations Resolution similar to HPTLC
"S" HPTLC	The ultimate in separating power; 3-10 times the resolving power of TLC. Technology and separation dependant on a 3 micron particle; 100 micron layer. Separate nanogram - picogram quantities. Spots of 1-2 mm will optimize separations.	Smallest TLC particle (micron), highest resolution Fast analyses Thin, highly reflective surface
Prep TLC
Prep TLC	Select 100, 200, 250, 500, 1,000, and 2000 micron layers according to the amount of material to be separated.	Readily Isolate mg - gms Standardized particle for prep TLC, Prep LC Wide variety of prep TLC Layers
"S" HPTLC	The ultimate in separating power; 3-10 times the resolving power of TLC. Technology and separation dependant on a 3 micron particle; 100 micron layer. Separate nanogram - picogram quantities. Spots of 1-2 mm will optimize separations.	Smallest TLC particle (micron), highest resolution Fast analyses Thin, highly reflective surface
Selected Backings
Glass Backing	Use glass for optimum separation and with aggressive mobile phases. Inert backing will not react with selected detection sprays. Easy to handle. Best resolution.	Resistant to virtually all sprays, eluants Rigid support for optimum Resolution Available in micro-macro sizes
Plastic and Aluminum Backing	Unbreakable and easy to handle. Cut into any size. Easy to isolate one spot for subsequent elution/detection. Can be easily included (attached) to lab reports.	Cut into virtually any size Readily isolate any spot for Subsequent detection Ideal for documentation

Applications

Separation of Phenothiazine Derivatives on Basic Aluminum Oxide TLC Plates

Phenothiazine salts migrate little, if at all, on acid aluminum oxide plates. On layers of neutral and  more particularly basic Aluminum Oxide TLC layers, good migration is achieved by virtue of exchange processes (similar to those with alkaloid salts on aluminum oxide layers). Benzene is a suitable developing solvent with the addition of 5% acetone. Dragendorff reagent is used as a developer. If the acetone content is increased, the Rf-value becomes greater.

	Pure substance	Drops	Ampoules
Phenothiazine	RF-value	RF-value	RF-value
Megaphen	0.51	0.54	0.53
Verophen	0.31	0.36	0.40
Atosil	0.58	0.56	0.61
Lorusil	0.22	—	0.24
Randolectil	0.23	—	0.23
Neurocil	0.71	—	0.71
Latibon	0.84	—	0.85
Andantol	0.42	—	0.48

Identification of Methaqualone in Tissue and Blood via TLC and Mass Spectrometry

It is difficult to distinguish between methaqualone and substances with simular Rf-values via thin-layer chromatography. If this problem arises, methaqualone may be identified by the mass spectrum of the substances adhering to the adsorbent.

Chromatographic examination of autopsy-blood extract contaminated with decomposistion products of hemoglobin, was carried out on Silica Gel F TLC, using chloroform/acetone 9+1 (v/v) and Dragendorff reagent, and showed a substance spot at Rf=0.80-0.83.

The reference substances showed the following Rf values:

Methaqualone=0.84
Gluethimide=0.78

For improving the differentiation, the spot detected on the plate under UV-light was scraped off, the sample was extracted with diethyl ether, decanted, enriched in a small amount of Silica Gel and placed directly into the ion-source of the mass spectrometer.

The attached figure shows the mass spectra of the sample and of the pure substance methaqualone. Quantities of about 15-20 μg. of methaqualone can be reliably detected by means of this procedure.

Detection of Barbituric Acid Derivatives by TLC and
Mass Spectrometry in Autopsy Material

The identification of about 20-25μg of 12 barbiturates as well as Cabromal and Bromisoval, which are often present in pharmaceutical specialties together with 4 barbituric acids, is possible by mean of a combination of thin-layer chromatography and mass spectrometry.

Autopsy material is extracted with a solution of tartaric 5. acid in ethanol after homogenization. the ethanol is evaporated and the residue dissolved by warm water.

After filtration, the tartaric filtrate is extracted with ether and the ether dried over sodium sulfate and evaporated. Urine, after addition of hydrochloric acid (pH 3-4), is exhaustively extracted by ether. The ether is dried over sodium sulfate, treated with a small amount of active carbon and Aluminum Oxide neutral, Act. 1, for a short time, and finely evaporated.

The residue is chromatographed on Silica Gel GF TLC with the solvent chloroform/acetone 9:1. For the detection of substance spots the thin-layer chromatograms are sprayed with mercurous-
(I)-nitrate, Zwikkers reagent, and mercurous-(II) sulfate/diphenylcarbazone.

Two samples each of the test material are spotted adjacent to each other. Both samples are primarily evaluated under UV-light. One sample is used for a color test and the corresponding zones of the second sample for the mass spectrometry. For this purpose the single spots are scrapped off, extracted by ether, and the ether is decanted and evaporated. The substances so enriched are brought directly into the ion source of the mass spectrometer. They allow mass spectra, which can be reliably evaluated.

Identification of Selected Pesticides via Thin-Layer Chromatography

For the detection of pesticide residues in food many methods are published, which in most cases require a considerable amount of apparatus, reagents and time. The separation technique should allow quick detection of the quantity of pesticide residue without much expediture, and only with small amounts of solvents. This preliminary data will then dictate whether a precise determination of the identified pesticide should follow or whether the approximate value obtained by spot comparison is sufficient.

Summary of 15 substances to be detected include:

1. Chlorinated hydrocarbons:
   DDT, deildrin, aldrin, lidane, endsulfan (I and II) as well as
   pentachloronitrobenzene(PCNB) and
   tetrachloronitrobenzene (TCNB)

2. Phosphoric acid esters:
   Parathion, dimethoate, bromophos

3. Fungicides:
   Pentachloronitrobenzene (PCNB)
   tetrachloronitrobenzene (TCNB), dichlofluanid
   as well as its metabolite DMSA

4. Bacteriostatics:
   IPC (N-phenyl isopropyl carbamate; propham

5. Herbicides:
   N-(3-chloro-4methypheny)
   -2-methypentanamide (solan)

Technique: The plant material is macerated with hexaneisopropyl alcohol (70:30); active substances are transferred into the hexane phase. After drying and removal of pigments a combination column (Alumina basic, activity V and Na2S04 on top) the yellow extract yield is directly spotted on a thin layer plate. Length of run always 17 cm. If too much wak is present, it should first be treated with acetonitrile. The sensitivity is usually at 2-6 μg of each active substance, but with DDT even 0.5 μg can be detected.

1. Chlorinated hydrocarbons are separated on silica gel G TLC in hexane/chloroform (9:1). Detection by spraying with AgNO3*

Aldrin	R1 0.83
PCNB	R1 0.71
DDT	R1 0.64
Lindane	R1 0.22
Endosulfan	R1 0.15
Dieldrin	R1 0.08

2. Phosphoric acid esters are separated on silica gel G TLC or on TLC-plates, pre-coated with silica gel F 254 in hexane/acetone (4:1).

Parathon	R1 0.45
Bromophos	R1 0.70
Dimethoate	R1 0.66

3-5. Fungicides, bacteriostatics and herbicides are separated in the same manner P-esters on TLC  plates, pre-coated with silica gel F 254, then diazotised, coupled and the color products evaluated in UV and visible light.

PCNB	R1 0.97
TCNB	R1 0.97 reddish
Solan	R1 0.49 blue
IPC	R1 0.52 yellowish
Dichlofluanid	R1 0.39
DMSA	R1 0.19 violet red

Thin-Layer Chromatography of Selected Indanol Derivatives of Pharmaceutical Interest

7-Chloro-4-hydroxy indan, 4-hydroxy-1, 5, 7-trimethyl indan and other indanol derivatives demonstrate excellent bactericidal, fungicidal and amebicidal properties. Thin-layer chromatography was found to be ideal for qualitative and quantitative control of these substances in pharmaceutical specialties.

Method: Silica Gel GF TLC

Solvent Systems:

• I Water-saturated chloroform
• I I Benzen/chloroform/abs, alcohol 4
• I Chloroform/abs. alcohol 4:1:1
• IV Benzene
• V Carbon tetrachloride

Direction: After development the thin-layer plates should be dried. Under UV 254 mm the substances appeared as dark spots against the greenish fluorescent background. If the fluorescent indicator is not available, the plates should be sprayed with an aqueous potassium permanganate solution (1%): yellow spots indicate the position of the various compounds on violet brown background.
 

Substances	R1 - Values with various Solvent systems on Silica Gel F-254
	I	II	III	IV	V
4-Hydroxy Indan	0.31	0.84	0.78	0.25	Start
5-Hydroxy Indan	0.22	0.82	0.72	0.18	Start
7-chloro-4-hydroxy Indan	0.28	0.78	0.72	0.23	Start
5,7-Dichloro-4-hydroxy Indan	0.69	0.89	0.91	0.63	0.31
7-chloro-4-hydroxy Indan-on (1)	0.60	0.92	0.94	0.34	0.08
5-Acetyl Indan	0.60	0.92	0.94	0.34	0.05
5-Amino Indan	0.79	Front	0.94	0.83	0.38
4-Hydroxy - 1,5,7-trimethl Indan	0.59	0.89	0.84	0.44	0.07

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Dynamic Adsorbents, Inc. P.O. Box 80402  Atlanta, GA 30366-0402
Tel: 770-817-0123 Toll-Free: 1-866-314-SORB (7672) Fax: 770-455-4380 e-mail: info@dynamicadsorbents.com