The Identification of Rubber Compounding Ingredients by Using Thin Layer Chromatography

1983 ◽  
Vol 56 (5) ◽  
pp. 1080-1095 ◽  
Author(s):  
B. J. Gedeon ◽  
T. Chu ◽  
S. Copeland

Abstract TLC is a quick, easy method to the identification of rubber compounding ingredients. Both silica gel absorbent and C18 absorbent are suitable for these identifications. With the mobile phases used in this study, a better separation of antioxidants is possible using silica gel absorbent. Work should be continued on finding suitable mobile phases for the C18 absorbent, since the Rf values are more reproducible. For those separations that require a separation of compounds of varying molecular weight, the C18 absorbent is superior to silica gel absorbent. The visualization systems that have been developed for use with silica gel absorbent are suitable for use with C18 absorbent. These systems give the same colors for either absorbent.

INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (12) ◽  
pp. 42-48
Author(s):  
P. J. Patel ◽  
◽  
D. A Shah ◽  
F. A. Mehta ◽  
U. K. Chhalotiya

A simple, sensitive and precise high performance thin layer chromatographic (HPTLC)method has been developed for the estimation of ondansetron (OND) and ranitidine (RAN) in combination. The method was employed on thin layer chromatography (TLC) and aluminium plates were precoated with silica gel 60 F254 as the stationary phase, while the solvent system was methanol. The Rf values were observed to be 0.5 ± 0.02, and 0.3 ± 0.02 for OND and RAN, respectively. The separated spots were densitometrically analyzed in absorbance mode at 299 nm. This method was linear in the range of 25-300 ng/band for OND and 50-600 ng/band for RAN. The limits of detection for OND and RAN were found to be 3.47 and 1.83 ng/band, respectively. The limits of quantification for OND and RAN were found to be 10.53 and 5.55 ng/band, respectively. The proposed method was validated with respect to linearity, accuracy, precision and robustness. The method was successfully applied to the estimation of OND and RAN in combined dosage form.


2003 ◽  
Vol 68 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Marijana Acanski ◽  
Suzana Jovanovic-Santa ◽  
Lidija Jevric

The retention behavior and separation ability of a series of new 16,17-secoestrone derivatives has been studied on silica gel, alumina and C-18 silica gel layers with non-aqueous and aqueous-organic mobile phases. The retention behavior and separation ability are discussed in terms of the nature of the solute, eluent and stationary phase.


1966 ◽  
Vol 49 (4) ◽  
pp. 795-800
Author(s):  
William A Moats

Abstract Butterfat and milk samples were analyzed for chlorinated insecticides by thin layer chromatography (TLC) on aluminum oxide or silica gel plates containing a small amount of silver nitrate. The adsorbent was washed with distilled water before preparing the plates. A one-step cleanup on a partially inactivated Florisil column was performed prior to TLC analysis. For color development, the TLC plates were sprayed lightly with hydrogen peroxide to suppress possible interference from fat and then steamed before exposure to ultraviolet light to accelerate and intensify the color reaction. Rf values for a number of solvent systems on aluminum oxide and silica gel plates are given. With this procedure, 0.05 μg or less of insecticide can be detected in a 0.4 g butterfat sample or the extract from 10 ml milk.


1979 ◽  
Vol 62 (4) ◽  
pp. 917-920 ◽  
Author(s):  
Irene Kushnir

Abstract A highly sensitive procedure has been developed to detect the undeclared addition of high fructose corn sirup (HFCS) to honey. Carbohydrates must be separated first to achieve the requisite degree of sensitivity: charcoal-Celite chromatography was used to isolate a fraction containing oligo- and polysaccharides. The fraction was then concentrated and examined by thin layer chromatography on silica gel. Pure honeys yielded only 1 or 2 blue-grey or bluebrown spots at Rf values >0.35; a series of spots or blue streaks extending from the origin characterized adulterated samples. The method detects HFCS and conventional honey adulterants at levels as low as 10% or less of the total mixture. In addition, the procedure detects the presence in honey of all starch-derived sugar sirups tested thus far, regardless of the plant source.


2000 ◽  
Vol 83 (6) ◽  
pp. 1502-1506 ◽  
Author(s):  
Jan Krzek ◽  
Anna Kwiecień ◽  
Małgorzata Starek ◽  
Anna Kierszniewska ◽  
Włodzimierz Rzeszutko

Abstract A thin-layer chromatographic/densitometric method was developed for the identification and quantitation of oxytetracycline, tiamulin, lincomycin, and spectinomycin in veterinary preparations. Silica gel-coated thin layer chromatography plates and 2 mobile phases were used to separate these constituents. The appropriate compositions of the suitable mobile phases were established: 10% citric acid solution–n-hexane–ethanol (80 + 1 + 1, v/v) and n–butanol–ethanol–chloroform– 25% ammonia (4 + 5 + 2 + 5, v/v). Along with Rf values and spot colors, direct UV and visual densitometric measurements were used for identification. Similar measuring ranges were used for quantitative analysis to obtain repeatable and reliable results for the preparations examined. The results of the quantitative analysis are characterized by a small confidence interval and are close to the declared contents of active constituents: oxytetracycline 30.01 ± 0.38 g at λ = 350 nm and 30.24 ± 0.86 g at λ = 430 nm; tiamulin, 10.19 ± 0.86 g at λ = 450 nm; lincomycin, 2.27 ± 0.08 g at λ = 278 nm; and spectinomycin, 2.18 ± 0.07 g at λ = 421 nm. The recoveries for all antibiotics ranged from 100.01 to 102.54%.


1969 ◽  
Vol 42 (2) ◽  
pp. 625-635 ◽  
Author(s):  
K. Nagasawa ◽  
K. Ohta

Abstract As a result of a search for a method for the simultaneous analysis of organic compounding ingredients in vulcanized rubber by one dimensional and two dimensional thin layer chromatography, a method was discovered by which it was possible to identify directly 24 accelerators and 19 antioxidants. The sample was developed on a Wakogel B-5 (silica gel) plate with chloroform/benzene (10/9) in one direction and then with ethanol in the other direction. The plate was sprayed with formalin/sulfuric acid (1/4) and then heated for one hour at 120° C. It was found that the 43 compounding ingredients could all be identified from their Rƒ values and the colors of the spots. Good results were also obtained in the actual analysis of the organic compounding ingredients in vulcanized rubbers. Investigation of interference by the base rubbers showed that the organic compounding ingredients could be identified. Translator's note: According to the English summary, the silica gel contains 5% of calcined gypsum. This is not mentioned in the Japanese text.


1973 ◽  
Vol 56 (2) ◽  
pp. 367-372
Author(s):  
David L Stalling ◽  
James N Huckins

Abstract The components of Aroclors® 1232, 1248, 1254, and 1260; Halowaxes® 1099, 1013, and 1014; and several chlorinated pesticides are resolved by reverse phase thin layer chromatography (RPTLC), which permits component separation by partition between a nonpolar stationary phase and a polar mobile phase. Rf values of resulting spots were calculated for 2 of 4 new solvent systems (mobile phases). RPTLC patterns were reproducible and characteristic of each material examined. The spots were recovered from the plates and characterized by gas-liquid chromatography (GLC) and/or GLC-mass spectrometry. In some cases, single GLC peaks of Aroclor standards were resolved into more than one component by RPTLC, whereas some RPTLC spots of Halowaxes were resolved into as many as 4 GLC peaks. The analysis of environmental residues of chlorinated compounds was facilitated by this technique.


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