Twin trough chamber

Among the verity of PP those containing flavonoids and lipophilic plant ingredients were selected as widely used and rather labile. Sample preparation varied to accommodate certain product type. Samples were chromatographied on Sorbfill HPTLC plates in saturated twin trough chamber. 

Polycyclic aromatic hydrocarbons (PAH) Apply sample solution and dry. Place TLX2 plate for 20 min in a twin-trough chamber containing phosphorus pentoxide to which 2 to 3 ml cone, nitric acid have been added. PAH nitrated by nitrous fumes. [20]... 

Fig. 43 Twin-trough chambers (A) and conditioning chamber (B) (Camag).

The twin-trough chamber (Fig. 43A) was not just developed to economize in mobile phase it also allows the layer to be impregnated as desired from the vapor... 

The chromatograms are dried in a stream of cold air (alkaloids 110 —120°C for 25 min in drying cupboard) and placed for 15 min in a twin-trough chamber — in the case of alkaloids while still hot — whose second trough contains 10 ml 25% ammonia solution. 

Detection and result The chromatogram was heated in the drying cupboard to 110 —120°C for 25 min and immediately placed — while still hot - in a twin-trough chamber, whose second trough contained 10 ml 25% ammonia solution, for 15 min. The chromatogram was then immersed for 2 s in a solution of liquid paraffin — n-hexane (1 + 2). 

Ascending, one-dimensional development in a twin-trough chamber. 

Note Note that the diazotization of primary aromatic amines can also be achieved by placing the chromatogram for 3 — 5 min in a twin-trough chamber containing nitrous fumes (fume cupboard ). The fumes are produced in the empty trough of the chamber by addition of 25% hydrochloric acid to a 20% sodium nitrite solution [2, 4], iV-(l-Naphthyl)ethylenediamine can be replaced in the reagent by a- or -naphthol [10, 14], but this reduces the sensitivity of detection [2]. Spray solutions Ila and lib can also be used as dipping solutions. 

Detection and result The chromatogram was freed from mobile phase (10 min in a stream of warm air) and placed for 10 min in the empty half of a twin-trough chamber in whose second half nitrous fumes were being generated by the addition of 10 drops 37% hydrochloric acid to 5 ml 20% aqueous sodium nitrite solution. After the nitrous fumes had cleared (3 —5 min in air, fume cupboard ) the chromatogram was immersed in solution Ila for 1 s and dried in a stream of cold air. 

Ascending, one-dimensional development in a twin-trough chamber with chamber saturation with the layer being preconditioned in the solvent-free half of the trough for 15 min after application of the sample. 

Detection and result The chromatogram was dried in a current of warm air and either immersed in reagent solution I for 1 s or placed for 15 min in a twin-trough chamber in whose second trough 5 ml of dipping solution I had been placed ca. 10 min previously. If the chromatogram was derivatized by dipping it had to be dried for ca. 1 min in a stream of hot air and allowed to cool to room temperature. 

Detection and result The chromatogram was freed from mobile phase in a stream of warm air, then immersed in dipping solution I for 1 s, dried for 90 s in a stream of warm air and after cooUng immersed in dipping solution II for 1 s. After drying briefly in a stream of warm air it was heated to 110°C for 2 min and treated with hydrochloric acid vapor for 15 min in a twin-trough chamber (37% hydrochloric acid in the vacant trough). 

The chromatograms stained with ninhydrin are immersed in the reagent solution for 1 s or sprayed evenly with it and then placed in the free half of a twin-trough chamber containing 25% ammonia solution. Apart from proline and hydroxyproline, which yield yellow copper complexes, all the amino acids yield reddish-colored chromatogram zones [3],... 

Note If the spray solution or a nonbasic dipping solution [2] is employed for detection then it is advisable to spray again with a 10% aqueous sodimn carbonate solution. The necessary basicity can also often be achieved by placing the treated chromatogram in a twin-trough chamber whose second trough contains 5 ml ammonia solution (25%). 

Ascending, one-dimensional development at 10 —12 °C in a twin-trough chamber with 5 ml cone, ammonia solution in the trough containing no mobile phase (chamber saturation 15 min). 

Ascending, one-dimensional multiple development method (stepwise technique, drying between each run) in two mobile phase systems in a twin-trough chamber without chamber saturation (equilibration 30 min at 20-22°C) at a relative humidity of 60 — 70%. 

Reagent solution Place 10 ml cone, sulfuric acid in a twin-trough chamber and add 2 ml cone, hydrochloric acid dropwise and with care. 

Ascending, one-dimensional development at 10 —12°C in a twin-trough chamber, with 25% ammonia in that part not containing mobile phase. The chamber was equihbrated for 15 min before starting development. 

Blue zones appear immediately or after a few minutes on a yellow background. The background can then be lightened [7] by placing the chromatogram in a twin-trough chamber whose second trough contains 25% ammonia solution. 

Formaldehyde gas Fill one trough of a twin-trough chamber with 20 ml formalin solution (37%) [1, 2]. 

Hydrochloric acid vapor This can be generated by placing 10 ml fuming hydrochloric acid (371 o) in one trough of a twin-trough chamber. 

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