Study On Distinguishing Shaoshui-oil In Restaurants Rapidly

In China, the economy goes up at very fast speed, which lead the demand of edible oil increased, and producing a number of shaoshui-oil (oil being gained from sewer). In order to get more and lawless profits, badmen refine the shaoshui-oil simply, and sell it to little restaurants in lower price. The shaoshui-oil is badly endangering the health of people. Now, research report about the shaoshui-oil is few in our nation and overseas. For the sake of the shaoshui-oil being examined in time and by rule and line, keeping the shaoshui-oil from using in restaurants. It's instancy to investigate the methods of examining the shaoshui-oil rapidly and efficiently.This paper investigates the methods of examining the shaoshui-oil rapidly by some experiments. The progress has been reviewed on several aspects:1. A drip of eligible edible oil on the silica gel plate mixing bromcresol green indicator, the color of the silica gel plate don't change. A drip of the shaoshui-oil on the silica gel plate, the color of the silica gel plate become yellow. The method can determine shaoshui-oil, and edible oil mixed with shaoshui-oil primitively.2. The electrical conductivity of water phase by mixing the eligible edible oil and water is below 10μs·cm^-1. However the electrical conductivity of the water phase by mixing shaoshui-oil and water is above 100 μs·cm^-1. Measuring the electrical conductivity is a method to identify the shaoshui-oil and eligible edible oil. The content of shaoshui-oil mixing with the eligible edible oil is linearity with the electrical conductivity of water phase.3. Using thin-layer chromatography separate the shaoshui-oil and the eligible edible oil, we find there exist same spots at Rf=0.73 on chromatosheet. While the shaoshui-oil appeares trailing spot on chromatosheet at Rf=0.4 which don't exist on eligible edible oil's chromatosheet. The trailing spot is a special spot, we can distinguish the shaoshui-oil and eligible edible oil according the special spot. Then analysis the ingredient of trailing spot by infra-red sepectrometry, there are aldehyde and ketone compounds.4. We distinguish the shaoshui-oil and the eligible edible oil by fluorescencemethod determining neopelex. There exist apices at A. ex/ A. em=230/290 nm in the fluorescence spectrum of the water phase gained from the shaoshui-oil. While there don't exist apices at A ex/ A em=230/290 nm in the fluorescence spectrum of the water phase gained from the eligible edible oil. Intensity of apices at A em=::290 nm is relative with the content of the shaoshui-oil mixing with the eligible edible oil.5. Ultraviolet-visible adsorption spectroscopy scan the shaoshui-oil and the eligible edible oil. Peanut oil exist three special adsorption peak at A =427 nm> 452 niiK 478 nm. While the shaoshui oil exist a special adsorption peak at A = 668 nm. Intensity of special adsorption peak is relative with the content of the shaoshui-oil mixing with the eligible edible oil. According difference of curve of spectrum, we can distinguish the shaoshui-oil and the eligible edible oil.