No abstract

Lycopene, a-carotene and 6-carotene in canned vegetable juice were determined by high performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (LC/APCI-MS) with selected ion monitoring (SIM). The extracted carotenoids were separated on a C-18 reversed phase column with methanol as the mobile phase and cholesterol benzoate as an internal standard (IS). In order to obtain good repeatability, only the peak portion of analytes eluted from the LC column was introduced into the APCI interface by using an auto switching valve. In the positive mode, lycopene, a-carotene and 3-carotene were monitored at m/z 537 and IS was monitored at m/z 369. The limit of detection was 1ng (s/n=4) and the recoveries of lycopene, a-carotene and 3-carotene were 85.1%, 80.0% and 82.8%, respectively. This SIM determination using LC/APCI-MS allows the analyte in samples to be determined without the influence of co-existing substances which cause problems in LC-UV chromatography.

No abstract

The effects of feeding of saturated and unsaturated fatty acids on the contents of short-chain fatty acids (SCFAs) derived from bacterial fermentation in the colon were examined in rats. The concentration of lipids in the feces was also measured. Tripalmitin or safflower oil at the concentration of 10% (w/w) in the diet with 5% (w/w) corn oil were used as the source of saturated or unsaturated fatty acids, respectively.