RESUMEN
A method is described for determining the artificial sweetener aspartame in beverages and beverage mixes by liquid chromatography. Aspartame is separated on a microC18 column, using a mobile phase of acetic acid, water, and isopropyl alcohol at pH 3.0 and UV detection at 254 nm. Beverages are filtered through 0.45 micron filters and injected directly into the chromatograph. Aspartame is eluted in approximately 7 min. Detection of aspartame is confirmed by a UV scan of the trapped peak. Aspartame is quantitated in the presence of other beverage additives such as saccharin, caffeine, sodium benzoate, artificial colors, and artificial flavors. Results are presented for spiked soda beverages, beverages from fruit-flavored mixes, instant tea, reconstituted presweetened drink mixes, and a powdered tabletop sweetener.
Asunto(s)
Aspartame/análisis , Bebidas/análisis , Dipéptidos/análisis , Cromatografía Liquida/métodos , Espectrofotometría Ultravioleta/métodosRESUMEN
Supplementary biotin (1 mg d-biotin/kg feed) increased the compressive strength of the mid-abaxial sidewall region of pig's hoof from 9.3 (+/- 0.5) X 10(6) N/m2 to 12.0 (+/- 0.5) X 10(6) N/m2 (P less than 0.05). It also increased the hardness of this region, measured on the Shore A and D hardness scales (P less than 0.05). The leading edge of the hoof wall was significantly stronger than the sidewall (P less than 0.001) with a compressive strength of 14.5 (+/- 0.7) X 10(6) N/m2. This site showed no significant improvement in compressive strength or hardness in response to biotin. Biotin also produced a significant decrease in the hardness of the heel bulb on the Shore A scale (P less than 0.05). There would therefore appear to be a rational biomechanical basis for the finding by others that biotin reduces lameness. The Shore A and D hardness testers are sensitive to the improvement produced by biotin and may be useful as small, hand-held hoof testing devices for use in field conditions by the practising veterinarian.
Asunto(s)
Biotina/farmacología , Alimentos Fortificados , Pezuñas y Garras/efectos de los fármacos , Porcinos , Animales , Fenómenos Biomecánicos , Biotina/administración & dosificación , Dureza , Caballos , Estrés MecánicoRESUMEN
A number of analogs of a new antineoplastic agent, 1-(m-ethoxymethyloxyphenyl)-1-nonen-3-one (IIIa) were prepared and evaluated against murine P-388 lymphocytic leukemia. Metabolic studies of IIIa in rats showed that it was sequestered rapidly to the brain and hence probably to other adipose tissue, which may account for the absence of IIIa and metabolites in urine and feces. A detailed toxicological evaluation of IIIa in rats showed marked pathological changes principally in the liver and spleen as a result of erythrophagocytosis from bleeding into the abdomen.
Asunto(s)
Antineoplásicos/síntesis química , Cetonas/síntesis química , Cetonas/metabolismo , Leucemia P388/tratamiento farmacológico , Leucemia Experimental/tratamiento farmacológico , Animales , Antineoplásicos/metabolismo , Biotransformación , Encéfalo/metabolismo , Fenómenos Químicos , Química , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Cetonas/farmacología , Masculino , Ratas , Ratas EndogámicasRESUMEN
A collaborative study was conducted using a modified AOAC method (sugars in chocolate) for the determination of fructose, glucose, sucrose, and maltose in presweetened cereals by high pressure liquid chromatography (HPLC). Eight samples consisting of 6 products were analyzed in duplicate by the HPLC method and the AOAC Lane-Eynon method. The AOAC method was modified to use water-alcohol (1 + 1) and Sep-Pak C18 cartridges for sample cleanup. The HPLC results indicate precision comparable to the lane-Eynon method and the chocolate method. The modified HPLC method has been adopted official first action.
Asunto(s)
Disacáridos/análisis , Grano Comestible/análisis , Monosacáridos/análisis , Cromatografía Líquida de Alta Presión/métodosRESUMEN
A new surface adsorbent technique has been compared with the widely used resin sponge T3 uptake method. The new technique has the desired attributes, correlates very highly with the resin sponge method (r = 0.93) and has been accepted as a simple, rapid and reliable method under normal temperature conditions. However, under extreme conditions (0-20 degrees C and 30-60 degrees C) the test is unreliable.