Analysis of Dairy Products for Chlorinated Insecticide Residues by Thin Layer Chromatography

1966 ◽  
Vol 49 (4) ◽  
pp. 795-800
Author(s):  
William A Moats
Keyword(s):  
Aluminum Oxide ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Color Development ◽  
Tlc Plates ◽  
One Step ◽  
Rf Values ◽  
Tlc Analysis ◽  
Layer Chromatography

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.

DEVELOPMENT OF HPTLC METHOD FOR THE ESTIMATION OF ONDANSETRON AND RANITIDINE IN COMBINED DOSAGE FORM

INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (12) ◽  
pp. 42-48
Author(s):  
P. J. Patel ◽  
◽  
D. A Shah ◽  
F. A. Mehta ◽  
U. K. Chhalotiya
Keyword(s):  
Thin Layer ◽  
Stationary Phase ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
High Performance ◽  
Dosage Form ◽  
Solvent System ◽  
Rf Values ◽  
Layer Chromatography ◽  
Hptlc Method

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.

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
Keyword(s):  
Molecular Weight ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Easy Method ◽  
Mobile Phases ◽  
Rf Values ◽  
Visualization Systems ◽  
Layer Chromatography

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.

Sensitive Thin Layer Chromatographic Detection of High Fructose Corn Sirup and Other Adulterants in Honey

1979 ◽  
Vol 62 (4) ◽  
pp. 917-920 ◽  
Author(s):  
Irene Kushnir
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Plant Source ◽  
High Fructose ◽  
Highly Sensitive ◽  
Rf Values ◽  
Chromatographic Detection ◽  
Total Mixture ◽  
Layer Chromatography

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.

Thin-layer chromatography of free porphyrins for diagnosis of porphyria.

1989 ◽  
Vol 35 (6) ◽  
pp. 1043-1044 ◽  
Author(s):  
M J Henderson
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Screening Tests ◽  
Fluorescent Light ◽  
Comprehensive Investigation ◽  
Long Wave ◽  
Tlc Plates ◽  
Layer Chromatography

Abstract In this simple thin-layer chromatographic (TLC) technique for evaluating porphyrin excretion, porphyrins are extracted from urine or feces, then separated on silica-gel TLC plates. The distinct porphyrin bands are observed by viewing the plates under long-wave fluorescent light. Positive screening tests can readily be confirmed or rejected, and a more comprehensive investigation confidently undertaken.

Identification of Organic Compounding Ingredients in Vulcanized Rubbers by Thin Layer Chromatography

1969 ◽  
Vol 42 (2) ◽  
pp. 625-635 ◽  
Author(s):  
K. Nagasawa ◽  
K. Ohta
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
English Summary ◽  
Two Dimensional ◽  
One Dimensional ◽  
Vulcanized Rubber ◽  
Rf Values ◽  
Calcined Gypsum ◽  
Layer Chromatography

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.

Thin Layer Chromatography of Organophosphorus Insecticides with Several Adsorbents and Ternary Solvent Systems

1968 ◽  
Vol 51 (5) ◽  
pp. 1101-1107 ◽  
Author(s):  
Melvix E Getz ◽  
Helen G Wheeler
Keyword(s):  
Aluminum Oxide ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Magnesium Silicate ◽  
Organophosphorus Insecticides ◽  
Binder Free ◽  
Solvent Systems ◽  
Layer Chromatography

Abstract Forty-two organophosphorus insecticides were chromatographed on binder-free thin layer plates prepared from silica gel, aluminum oxide, and magnesium silicate. Five ternary solvent systems were used for the development and three selective chromogenic sprays for the identification of the migrated spots

Separation of dl-2-(3-Phenoxyphenyl) propionic Acid (Fenoprofen) From Its Intermediates by Thin Layer Chromatography

1973 ◽  
Vol 56 (3) ◽  
pp. 656-658
Author(s):  
Rafik H Bishara
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Lower Limit ◽  
Raw Material ◽  
Chemical Constitution ◽  
Tlc Plates ◽  
Rf Values ◽  
Synthetic Intermediates ◽  
Layer Chromatography

Abstract Fenoprofen and its synthetic intermediates are resolved on silica gel F254 TLC plates developed with chloroform-acetic acid (98+2). The interrelationship between the chemical constitution and the Rf values is discussed. The lower limit of detecting the intermediates in Fenoprofen raw material is 1%.

A Comparison of Assay Procedures for Aflatoxin in Peanut Products

1964 ◽  
Vol 47 (6) ◽  
pp. 993-1001
Author(s):  
W T Tracer ◽  
L Stoloff ◽  
A D Campbell
Keyword(s):  
Aluminum Oxide ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Quantitative Estimation ◽  
Peanut Butter ◽  
Peanut Meal ◽  
The Other ◽  
Thinlayer Chromatography ◽  
Layer Chromatography

Abstract A number of analytical procedures for aflatoxin assays, which were used in the autumn of 1963 by government and industry laboratories, were compared for their efficacy in the detection and quantitative estimation of aflatoxin in peanut meal and peanut butter. All but one of these procedures employed aluminum oxide thin-layer chromatography in the determinative step, but the method employing silica gel thinlayer chromatography was shown to be superior to the aluminum oxide technique. When silica gel was used as the determinative step in each of the procedures, all but one were found to be approximately equal. The other procedure did not effectively extract the aflatoxin.

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