RESUMO
The determination of pantothenic acid in infant formula was carried out by means of HPLC. The sample was dissolved in deionizid water and put in an ultra-sonic generator for 15 minutes, adjust pH to precipitate protein. After centrifugation the supernatants were used as test sample for HPLC analysis. Column: Bondapak C18, Detector: ultraviolet 200nm, and 0.01M KH2PO4/CH3OH as eluant. Coefficient of variation was 6.58% and recovery was 93.78%.The method might be applicable to milk and milk products and alsoto the samples containing free pantothenic acid such as wheat germ and flour.
RESUMO
Vitamine E in peanut oil was determined by means of f Juorometric method (Ex = 285nm, Em=324nm) and TLC scanning method (? = 292nm). Both methods include saponification of the oil, isolation o'f the unsaponifiable matters and the respective final measurements. The result of the former method indicates the total vitamine E in terms of ?-vitamine E and the latter method may indicate their ?,?,? and 6 analogues separately. These two methods are simple, time-saving and reliable. The recovery of VE and the standard deviation of replication of fluorometric method and TLC scanning method are 99.3%, ? 0.587mg/100g sample and 103.04%, ?0.959mg/100g sample respectively. Both methods are also applicable to other foods such as fortified cakes, confectionaries, infant foods etc., but the oil in these samples must be extracted before saponification.
RESUMO
The determination of vitamine D in fortified milk powder was carried out by means of HPLC. Its pre-treatments include extraction of fat, sap onification, isolation of the unsaponifiable matters, and digitonin-celite and bentonite column chromatography. The HPLC was performed with 15cm ? 4mm column of silica 5m 0.7% ethyl alcohol in iso-octane as mobile phase, at 254nm. Only 12 grams of sample which contained 400-500 IU vitamin D/100 g were used. Within the sample there were relatively large amounts of interfering materials such as fats, sterols,?-carotene, vitamin A, vitamin E and their decomposed products, but they could be separated by the above method. The recovery rate of vitamin D was 81% with standard deviation of 0.39?g/100g. This method could also be applied to other samples such as fortified cakes, confectionaries, infant foods and "Mairujing" (milk maltose mixture powder) etc.