Determination of allicin by sulfur assay. Accurately suck garlic extract 10ml (equivalent to 5g fresh garlic), add 5 ~ 6ml concentrated nitric acid, stir with a glass rod until yellow, let stand for 20min, filter, wash into a 100mL volumetric flask, and adjust the volume to scale. Suck 80mL of filtrate, put it in a beaker of 150mL, add 5 drops of 0. 1% methyl orange indicator, add 10%NaOH solution to yellow, and adjust the pH to 2-with1:1kloc-0/ Heat it in an electric furnace until it is slightly boiling, add lOmL 15% barium chloride solution while it is hot, stir it evenly, keep it in a 9o~c water bath for 2h, filter it with quantitative (ash-free) filter paper, wash it with hot deionized water until there is no chloride ion (until the filtrate is not turbid with silver nitrate solution), put the precipitate and filter paper into a porcelain crucible with constant weight in advance, carbonize it at low temperature, and then put it into a muffle furnace at 600℃.

Where: 32.06 is the molecular weight of sulfur; 233.39 is the molecular weight of barium sulfate; M is the weight of barium sulfate; 162.26 is the molecular weight of allicin; Trio is the sample weight; Vo is the total volume of the extract; V is the volume (mL) of the tested extract. Then the percentage of allicin was converted into (g/L).