Quantitative Determination of Carbaryl in Apples, Lettuce, and Water by Densitometry of Thin Layer Chromatograms

1978 ◽  
Vol 61 (3) ◽  
pp. 616-620
Author(s):  
Joseph Sherma ◽  
Andrew J Kovalchick ◽  
Richard Mack
Keyword(s):  
Thin Layer ◽  
Quantitative Determination ◽  
Fiber Optics ◽  
Silica Gel ◽  
Chromatographic Method ◽  
Visual Estimation ◽  
Carbamate Insecticides

Abstract A method for the quantitative determination of carbaryl insecticide by in situ densitometry was developed. After separation on silica gel thin layer plates, carbaryl residues were detected by using p-nitrobenzenediazonium fluoborate reagent and quantitated by scanning the resultant blue spots with a fiber optics densitometer and comparing them with standards. The method was applied to water fortified with carbaryl at 8 ppb and apples and lettuce fortified at 0.10 ppm; all recoveries were greater than 89%. The 2 crop extracts were cleaned up by using the AOAC thin layer chromatographic method for visual estimation of carbaryl. Related carbamate insecticides were detected by using the same reagent, and the potential for quantitation was demonstrated.

Thin Layer Chromatographic Determination of Subsidiary Dyes in D&C Red No. 19 and D&C Red No. 37

1974 ◽  
Vol 57 (4) ◽  
pp. 961-962
Author(s):  
Sandra Bell
Keyword(s):  
Thin Layer ◽  
Silica Gel ◽  
Chromatographic Method ◽  
Chromatographic Determination

Abstract A thin layer chromatographic method is presented by which triethylrhodamine and other lower ethylated subsidiary colors are separated from D&C Red No. 19 and D&C Red No. 37. After removal from the plate, subsidiary dyes are extracted from silica gel C adsorbent and quantitated spectrophotometrically. Recoveries of 1, 2, and 5% of added triethylrhodamine ranged from 89 to 1 0 3% for D&C Red No. 19 and from 85 to 1 0 2% for D&C Red No. 37.

Quantitative Determination of Tris-(2,3,-dibromopropyl) Phosphate by Densitometry of Thin Layer Chromatograms

1979 ◽  
Vol 62 (6) ◽  
pp. 1315-1318
Author(s):  
Albert M Gardner
Keyword(s):  
Sewage Sludge ◽  
Thin Layer ◽  
Quantitative Determination ◽  
Ethyl Acetate ◽  
Silver Nitrate ◽  
Flame Retardant ◽  
Silica Gel ◽  
White Background ◽  
Ppm Level

Abstract The flame retardant tris-(2,3-dibromopropyl) phosphate (Tris) was chromatographed on silica gel thin layer plates, using ethyl acetate-hexane (30+70) as the developing solvent. Tris was visualized by spraying the chromatogram with 1% aqueous silver nitrate followed by exposure to ultraviolet light for 40 min. Tris appeared as dark gray spots on a white background; the spots were quantitated by densitometry at 600 nm. The lower level of sensitivity was 50 ng; calibration plots were linear from 50 to 800 ng. The procedure was developed to determine the levels of unmetabolized Tris remaining after exposure to sewage sludge suspensions. Recovery of Tris from 3 sewage sludge samples fortified at the 1.0 ppm level averaged 97%.

In situ mineralization and determination of phosphorus in phospholipids on silica gel sintered thin-layer chromatographic plates

1988 ◽  
Vol 454 ◽  
pp. 432-437 ◽  
Author(s):  
Takashi Terabayashi ◽  
Tadao Ogawa ◽  
Yasuhiro Kawanishi ◽  
Jukichi Ishii
Keyword(s):  
Thin Layer ◽  
Silica Gel

Determination of Glutethimide (Doriden) and Its Metabolites in Biologic Specimens

1968 ◽  
Vol 14 (7) ◽  
pp. 595-609 ◽  
Author(s):  
Irving Sunshine ◽  
Robert Maes ◽  
Rosalie Faracci
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Quantitative Determination ◽  
Thin Layer Chromatography ◽  
Chromatographic Method ◽  
Blood Concentrations ◽  
Gas Chromatographic Method ◽  
Clinical Conditions ◽  
Layer Chromatography

Abstract A gas chromatographic method for the quantitative determination of glutethimide was developed. This method was applied to samples obtained from patients who were comatose because of acute glutethimide intoxication. The results obtained from this procedure were compared with those obtained by using an ultraviolet method. The patients’ clinical conditions were assessed and correlated with the blood concentrations of glutethimide. The samples were processed to isolate glutethimide, as well as its metabolites. The metabolites were separated using thin-layer chromatography and were checked for purity by both thin-layer and gas chromatography.

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