Mass spectrum of BHT

The mass spectrum of BHT is given in Figure 9.4. The most abundant fragment ion is that at m/z 205. The TG-MS curves are shown in Figure 9.5, which it can be seen that the TG curve is a typical S -shaped evaporation curve. It can be seen that, under these conditions, the rate of loss of BHT reaches a maximum at 100 10 °C. Although 100% weight loss... 

Figure 9.4 The mass spectrum of BHT, shown to illustrate the selection of characteristic ions for continuous ion monitoring. For this material, ions with mIz = 205 and 220 are suitable Reproduced from Keen and co-workers, Polymer Degradation and Stability [20]...

Dry clean tanshen rhizomes were powdered and extracted with hexane for three days at room temperature. The hexane solution was kept overnight and then filtered. After removal of the solvent a residue was obtained which was separated into seven colored fractions by column chromatography with silica gel. Miltirone was isolated by preparative tic from fraction 1 (light red) using hexane ethyl acetate (4 1) followed by benzene-acetone (20 1). The product obtained was recrystallized from ethylacetate, m.p. 100-101°C. Its structure was confirmed by mass spectrum, NMR, IR and UV spectra which agree quite closely with those of Ho et al [76], Miltirone showed antioxidant behavior comparable to that of the commonly used phenolics BHT and BEA [77], The antioxidant activity of miltirone in lard at 100°C was determined with a Rancimat. Miltirone and other related compounds may have the potential of being used as natural antioxidants in food and cosmetics. 

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