ITLC +/- silica

The radiochemical purity of the Re-DMSA(V) was determined by ITLC, using ITLC silica gel strips developed in 95% acetone. Tlie strips were dried and cut into 0.5 cm long segments, and the radioactivity was measured in a gamma counter (Ecko Electronics). The labelled molecule remained at the origin (Rf = 0), and the Rf for ReOi was found to be 0.9. 

System I Gelman ITLC silica gel fiberglass plates and 2-butanone (methyl ethyl ketone [MEK]) as solvent Reduced, hydrolized Tc-technetium (C) and the secondary Tc-HMPAO complex (A) remain at the start (A-tC) the lipophilic Tc-HMPAO complex (D) and unbound Tc-Na-pertechnetate (B) are measured at the solvent front (B+D). 

System I Gelman instant thin-layer chromatography (ITLC) silica gel fiberglass plates and 2-butanone (methyl ethyl ketone [MEK]) as solvent Reduced, hydrolized... 

Instant thin layer chromatography (ITLC) plates are prepared from ground-up glass fibers impregnated with silica gel. This provides a uniform plate, readily wetted by the more polar solvents so capillary action is rapid. The plates are fragile and should be handled accordingly. 

ITLC plates are made of fiberglass sheets, impregnated with an adsorbent, usually silica gel (e.g., SG). Due to the fine mesh material, the migration properties are increased many-fold by the TLC materials. The time for the development of any chromatogram may be reduced to < 5 min, without affecting the separation of radiochemical impurities. 

The separation properties of silica gel 60 depend to a certain extent on the activated state of the adsorbent, which is related to the water content. However, when using organic solvents, it is recommended to dry the ITLC plate before use by heating for 10-20 min at 110°C (Frier M and Hesslewood 1980). 

Silica Gel. The chemical properties are based on siloxane (Si-O-Si) and silanol (Si-OH). Polar groups are responsible for the interaction of the adsorbent with water and with the sample to be analyzed. Silica stationary phases (3-8 pm) have been produced for ITLC as silica gel (ITLC-SG) and silicic acid (ITLC-SA). ITLC-SG is the most frequently used adsorbent for routine radiochemical purity determinations (Table 9.1.1.1). 

Silica gel (ITLC-SG) 20x20 Pall Gelman 61886 25 sheets... 

Products were separated either on ITLC glass fibre mats (Gelman) or on glass plates produced from a slurry of silica gel G (Brinkmann). After solution was applied to these plates ammonia was added to neutralize the acid and chromatograms were developed with a 50% (V V) petroleum ether (30-60°C.) and benzene solvent. Bands or spots were extracted with ethyl alcohol or water. 

Chromatographic support material this can be Whatman 3MM chromatography paper, silica gel coated plastic TLC sheets, or silica gel impregnated glass fibre (ITLC) sheets (Gelman Sciences)... 

ITLC (instant TLC) plates are glass microfiber sheets. The addition of silicic acid or silica gel gives the additional designation of SA or SG respectively. The strength of the layer by multiple solvent systems allows the retention of adenine, and its associated structures. 

ITLC instant thin layer chromatography ITLC-SA with salicylic acid, ITLC-SG with silica gel LiCl lithium chloride... 

TLC of dyes on ion exchanger-impregnated plates, 1021-1023 ITLC (instant TLC) +/- silica, 925... 

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