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D Tonelli

Publications and source records attributed to D Tonelli.

40 records · Page 3Linked to original sources

Thin-layer chromatographic determination of indolic tryptophan metabolites in human urine using Sep-Pak C18 extraction.

Tryptophan and some of its indole metabolites were separated by thin-layer chromatography, stained with the Van Urk--Salkowski reagent, and quantitated by scanning densitometry. The application of this technique for the detection of the indoles in urine samples, employing Sep-Pak C18 cartridges for extraction, was demonstrated. The proposed method is simple and accurate. The detection limits were 2 micrograms/ml 5-hydroxytryptophan, 1.75 micrograms/ml 5-hydroxyindolyl-3-acetic acid, 1.5 micrograms/ml tryptophan, 0.8 micrograms/ml indolyl-3-acetic acid, 0.9 micrograms/ml indolyl-3-butyric acid, 1.75 micrograms/ml serotonin, and 1.25 micrograms/ml tryptamine.

Chromatography, Thin Layer↗

Effect of diflubenzuron and its major degradation products on the growth of Euglena gracilis Z. and incorporation of glycine-U-14C in protein.

Diflubenzuron (I) and its major degradation products 4-chlorophenyl urea (II), 2,6-difluorobenzoic acid (III) and 4-chloroaniline (IV) were tested for their activity on Euglena gracilis Z. The inhibition on the growth and on the incorporation of glycine-U-14C in the protein of Euglena was measured in the presence of I-IV ranging 10 to 200 ppm. 4-chloroaniline caused a considerable inhibition at every tested level whereas I-III slightly affected only the incorporation. Therefore, it must be inferred that diflubenzuron shows no effect on growth and protein biosynthesis for this nontarget organism.

Carbon Radioisotopes↗