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A substantially available identiˆcation system for Sildenaˆl in health foods was established using 3 diŠerent analytical methods; i.e. TLC, preparative TLC/MS and HPLC/photo-diode array. Sildenaˆl in health foods was extracted with ethyl acetate under alkaline conditions as sample solutions for TLC and preparative TLC, and also extracted with 50％ methanol and then diluted with solution of HPLC mobile phase for HPLC. The sample solution for TLC was applied to Silica gel 60 F 254 plates with chloroform/methanol/28％ ammonia (90：1：5, under layer) as mobile phase. Spots were located under UV radiation at 254 nm and 366 nm, and spraying dragendorŠ reagent. The conditions for preparative TLC were the same as these of TLC method, and samples abtained from preparative TLC were determined by MS with APCI interface, under both positive and negative modes. The HPLC analysis was carried out on a column of Cosmosil 5C18-AR(4.6 mm×150 mm, 5 mm) with 0.05 mol/l phosphate buŠer pH 3.0/acetonitrile(73：27) as mobile phase and the eluate was monitored by a photo-diode array detector. The quantitative analysis was available, when the peak of this sample on HPLC was detected at 290 nm. When this system was applied to commercial health foods, Sildenaˆl was identiˆed and their contents were 25 mg-45 mg/tablet or bottle. These contents nearly correspond to that in Viagra, 25 mg, 50 mg/tablet. Therefore, there is a fear of side eŠects for Sildenaˆl, when it is taken as health foods.

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A method for the determination of 12 synthetic food dyes (Amaranth, Erythrosine, Allura Red AC, New Coccine, Phloxine, Rose Bengal, Acid Red, Tartrazine, Sunset Yellow FCF, Fast Green FCF, Brilliant Blue FCF, Indigo Carmine) in food was developed using capillary electrophoresis (CE) with photodiode array detection.The dyes were extracted with water and 0.5 ammonia-ethanol (1 : 1) mixture, and cleaned up using solid-phase extraction (Sep-Pak Plus tC18). The dyes were eluted with methanol from the cartridge. The dyes were separated by CE on a bubble cell fused-silica capillary (72 cm to the detector, 75 mm i.d.) using 20 acetonitrile in a mixture of 10 mmol/L potassium phosphate, monobasic and 5 mmol/L sodium carbonate (pH 10.0) as the running bu#er. Identifications of the dyes were performed on the basis of the migration time and the absorbance spectrum of each peak. The coe$cients of variation of the migration times and the peak areas were 0.28ῌ0.62 and 1.84ῌ 4.30, respectively (n5). The identification limits using the absorbance spectra of the dyes were 10 mg/mL for Brilliant Blue FCF and Fast Green FCF, and 5 mg/mL for the other 10 dyes. The recoveries of the 12 dyes from pickles, soft drinks and candies at the level of 10 mg/g were 70.0ῌ 101.5. The method was applied to the analysis of dyes in foods. The dyes detected by CE were in agreement with those detected by paper chromatography.

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